General characteristics of the elements of the main subgroup of group V. Characteristics of elements of the main subgroup of group II: electron rotation around its own axis
16. Which of the gases taken with the same mass occupies the largest volume under the same conditions:
17. Determine the molar mass equivalent (g/mol) of sulfur in sulfur oxide (VI):
18. What is the mass fraction (%) of the metal in the oxide if the molar mass of the trivalent metal equivalent is 15 g/mol:
19. What is the relative molecular mass of a gas if this gas is 2.2 times heavier than air:
20. Which of the following equations is called the Mendeleev–Clapeyron equation:
3) PV = RT
21. List 3 gases that have the same density as any other gas:
1) CH 4, SO 2, Cl 2
2) C 2 H 4, CH 4, F 2
3) CO, Cl 2, H 2
4) CO, C 2 H 4, N 2
5)N 2, CH 4, H 2
22. How many moles of oxygen are formed from 3 moles of potassium chlorate during its complete thermal decomposition:
23. What amount (mol) of FeS 2 will be required to obtain 64 g of SO 2 according to the equation:
4 FeS 2 + 11O 2 = 2Fe 2 O 3 + 8SO 2;
24. What mass (g) of calcium carbonate will be consumed to produce 44.8 liters of carbon dioxide, measured at ambient conditions:
1) 200,0;
25. The equivalent of aluminum is:
1) aluminum atom;
2) 1/2 part aluminum atom;
3) 1/3 part aluminum atom;
4) two aluminum atoms;
5) 1 mole of aluminum atoms.
26. The law of constancy of the composition of substances is valid for substances:
1) with a molecular structure;
2) with a non-molecular structure;
3) with ionic crystal lattice;
4) with an atomic crystal lattice;
5) for oxides and salts.
27. The equivalent of magnesium is:
1) magnesium atom;
2) 1/2 part of a magnesium atom;
3) 1/3 part of a magnesium atom;
4) two magnesium atoms;
5) 1 mole of magnesium atoms.
28. To neutralize 2.45 g of acid, 2.80 g of potassium hydroxide is consumed. Define
molar mass of acid equivalent:
1) 98 g/mol;
2) 36.5 g/mol;
3) 63 g/mol;
4) 40 g/mol;
G/mol.
Classification and nomenclature of inorganic compounds
1) Na 2 O; CaO; CO2
2) SO 3; CuO; CrO3
3)Mn 2 O 7; CuO; CrO3
4) SO 3; CO2; P2O5
5) Na 2 O; H2O; CO2
30. Only acid oxides series:
1) CO 2; SiO2; MnO; CrO3
2) V 2 O 5; CrO3; TeO3; Mn2O7
3) CuO; SO2; NiO; MnO
4) CaO; P 2 O 3 ; Mn 2 O 7; Cr2O3
5) Na 2 O; H2O; CuO; Mn2O7
31. Cannot be used to neutralize sulfuric acid:
1) sodium bicarbonate;
2) magnesium oxide;
3) hydroxomagnesium chloride;
4) sodium hydrogen sulfate;
5) sodium oxide
32. To neutralize sulfuric acid you can use:
2) Mg(OH) 2
33. Using a glass tube, carbon dioxide is exhaled into solutions. The change will be in the solution:
3) Ca(OH) 2;
34. By dissolving the corresponding oxide in water you can obtain:
35. Under certain conditions, salt is formed in the case of:
1) N 2 O 5 +SO 3;
4) H 2 SO 4 +NH 3;
36. Can form acid salts:
1) H 3 PO 4;
37. Can form basic salts:
2) Ba(OH)2;
38. Mass of limestone required to produce 112 kg of quicklime:
39. Reacts with water:
2) CaO;
40. Soluble in water:
3) Ba(OH)2;
41. To obtain potassium phosphate, potassium hydrogen phosphate must be affected by:
42. Acid oxide:
3) Mn 2 O 7;
43. Will interact directly in an aqueous solution:
2) Cu(OH) 2 and ZnO;
3) AI 2 O 3 and HCI;
4) Rb 2 O and NaOH;
5) CaO and K 2 O.
44. All salts are acidic in the group:
1) KCI, CuOHCI, NaHSO 4;
2) KAI(SO 4) 2, Na, Ca(HCO 3) 2;
3) CuS, NaHSO 3, Cu(HS) 2;
4) NaHCO 3, Na 2 HPO 4, NaH 2 PO 4;
5) AIOHCI 2, NaHCO 3, NaCN.
45. Does not form acid salts:
4) HPO 3;
46. The title is spelled incorrectly:
1) ferrous sulfate;
2) potassium sulfate;
3) iron (II) hydrochloride;
4) copper (I) chloride;
5) ammonium sulfate.
47. When water is separated from a monobasic acid weighing 16.0 g, formed by an element in the oxidation state +5, an oxide weighing 14.56 g is obtained. The acid was taken:
1) nitrogen;
2) metavanadium;
3) orthophosphoric;
4) arsenic;
5) chloric.
48. When calcining metal (III) weighing 10.8 g in air, a metal oxide weighing 20.4 g was obtained. For calcination the following was taken:
2) aluminum AI;
3) iron Fe;
4) scandium Sc;
5) sodium Na.
49. Sign characterizing hydrochloric acid:
1) dibasic;
2) weak;
3) volatile;
4) oxygen-containing;
5) acid – oxidizing agent.
50. Dibasic acid:
1) nitrogen;
2) salt;
3) vinegar;
4) cyanide;
Selenium.
51. Monoprotic acid:
1) selenium;
2) phosphorous;
3) tellurium;
4) boric;
5) prussic
52. Two types of acid salts are formed:
1) sulfuric acid;
2) orthophosphoric acid;
3) metaphosphoric acid;
4) selenic acid;
5) sulfurous acid.
53. Does not form acid salts:
1) sulfuric acid;
2) orthophosphoric acid;
3) metaphosphoric acid;
4) selenic acid;
5) sulfurous acid.
54. Specify the cationic complex:
1) Na 3;
3) K 3;
4) CI 3;
5) K 2.
55. Complex non-electrolyte:
1) Na 3;
2) ;
3) K 3;
4) CI 3;
5) K 2.
56. Anion complex:
1) potassium hexacyanoferrate(III);
2) tetrachlorodiammineplatinum (IV);
3) diammine silver chloride;
57. Complex non-electrolyte:
1) potassium hexacyanoferrate (III);
2) tetrachlorodiammineplatinum (IV);
3) diammine silver chloride;
4) tetraammine copper (II) sulfate;
5) hexaaquachrome (III) chloride.
58. Formula of hexaaquachrome (III) chloride:
1) Na 3;
2) CI
3) CI 2;
4) CI 3;
5)K 2 Cr 2 O 7 .
59. Formula of hexaaquachrome (II) chloride:
1) Na 3;
2) CI
3) CI 2; 3bl
4) CI 3;
5)K 2 Cr 2 O 7 .
60. Yellow blood salt refers to:
1) To aqua complexes;
2) Hydrates;
3) To acidocomplexes;
4) To ammonia;
5) To chelates.
61. Copper sulfate refers to:
1) To aqua complexes;
2) Hydrates;
3) To acidocomplexes;
4) To ammonia;
5) To chelates.
62. To obtain CaCO 3, the following should be added to a solution of Ca(HCO 3) 2:
1) Ca(OH) 2;
“The structure of matter and the periodic law of D.I. Mendeleev"
63. In the nucleus of the most common lead isotope 207 Pb neutrons:
2) 125
64. Maximum number of electrons at level n = 3:
65. At an energy level with n = 4 sublevels:
66. Number of energy levels in a tungsten atom:
67. In the nucleus of the osmium atom there are protons:
68. The nucleus of a krypton atom contains:
P and 44n
69. Number of electrons in chromium ion:
70. An ion containing 18 electrons and 16 protons has a nuclear charge:
71. The maximum number of electrons that can occupy a 3s orbital:
72. The atom has the electronic configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1:
73. The designations of orbitals are incorrect:
3) 1p, 2d
74. The particle has the same electronic configuration as the argon atom:
1) Ca 2+
75. Electron affinity is called:
1) the energy required to remove an electron from an unexcited atom;
2) ability of the atom of this element to pulling electron density towards oneself;
3) transition of an electron to a higher energy level;
4) release of energy when an electron attaches to an atom or ion;
5) chemical bond energy.
76. As a result nuclear reaction 
isotope is formed:
77. In a hydrogen atom, absorption of a photon with minimal energy requires the transition of an electron:
78. The particle-wave nature of the electron is characterized by the equation:
79. For the valence electron of a potassium atom, the possible values of quantum numbers (n, l, m l , m s):
1) 4, 1, -1, - :
2) 4, 1, +1, + : 3bm
3) 4, 0, 0, + :
4) 5, 0, +1, + :
80. Charge of the nucleus of an atom whose configuration of valence electrons in the ground state is ...4d 2 5s 2:
81. The principal quantum number n determines:
1) the shape of the electron cloud;
2) electron energy;
82. Orbital quantum number l determines:
1) the shape of the electron cloud;
2) electron energy;
3) orientation of the electron cloud in space;
4) rotation of the electron around its own axis;
5) hybridization of the electron cloud.
83. Magnetic quantum number m determines:
1) the shape of the electron cloud;
2) electron energy;
3) orientation of the electron cloud in space;
4) rotation of the electron around its own axis;
5) hybridization of the electron cloud.
84. The spin quantum number m s determines:
1) the shape of the electron cloud;
2) electron energy;
3) orientation of the electron cloud in space;
4) rotation of the electron around its own axis;
5) hybridization of the electron cloud.
85. During - decay, the nucleus of an atom of a radioactive element emits:
1) electron;
2) positron;
4) two protons;
5) two neutrons.
86. During - - decay, the nucleus of an atom of a radioactive element emits:
1) electron;
2) positron;
3) two protons and two neutrons combined into the nucleus of a helium atom;
4) two protons;
5) two neutrons.
87. During + - decay, the nucleus of an atom of a radioactive element emits:
1) electron;
2) positron;
3) two protons and two neutrons combined into the nucleus of a helium atom;
4) two protons;
5) two neutrons.
88. The atomic orbital has the smallest value of the sum (n + l):
89. Highest value the sum (n + l) has an atomic orbital
90. The nitrogen atom will be more stable if at the 2p sublevel three electrons are distributed, one in each orbital. This matches the content:
2) Pauli principle;
3) Hund's Rules;
4) 1st Klechkovsky rule;
5) 2nd Klechkovsky rule.
91. The twenty-first electron of the scandium atom is located on the 3d sublevel, and not on the 4p sublevel. This matches the content:
1) The principle of least energy;
2) Pauli principle;
3) Hund's Rules;
4) 1st Klechkovsky rule;
5) 2nd Klechkovsky rule.
92. The nineteenth electron of the potassium atom is located on the 4s sublevel, and not on the 3d sublevel. This matches the content:
1) The principle of least energy;
2) Pauli principle;
3) Hund's Rules;
4) 1st Klechkovsky rule;
5) 2nd Klechkovsky rule.
93. The only electron of the hydrogen atom in the ground state is located at the first energy level. This matches the content:
1) The principle of least energy;
2) Pauli principle;
3) Hund's Rules;
4) 1st Klechkovsky rule;
5) 2nd Klechkovsky rule.
94. The maximum number of electrons at the second energy level of atoms of elements
equals 8. This corresponds to the content:
1) The principle of least energy;
2) Pauli principle;
3) Hund's Rules;
4) 1st Klechkovsky rule;
5) 2nd Klechkovsky rule.
95. One of the mechanisms for the formation of a covalent bond:
1) radical;
2) exchange;
3) molecular;
4) ionic;
5) chain.
96. An example of a non-polar molecule having a polar covalent bond would be:
4) CCl 4
97. Non-polar molecule:
98. In the series of molecules LiF - BeF 2 - BF 3 - CF 4 - NF 3 - OF 2 - F 2:
1) the nature of the connection does not change;
2) the ionic nature of the bond is enhanced;
3) the covalent nature of the bond weakens;
4) the covalent nature of the bond is enhanced;
5) there is no correct answer.
99. A covalent bond is formed in a molecule by a donor-acceptor mechanism:
2) CCl 4;
3) NH 4 C1;
4) NH 3;
100. In a nitrogen molecule the following are formed:
1) only - connections;
2) only - connections;
3) both - and - connections;
4) single bond;
5) double bond.
101. The methane molecule has the structure:
1) flat;
2) tetrahedral;
3) pyramidal;
4) square;
102. The formation of an ionic lattice is characteristic of:
1) cesium iodide;
2) graphite;
3) naphthalene;
4) diamond;
103. Which of the following substances is characterized by the formation of an atomic lattice:
1) ammonium nitrate;
2) diamond;
4) sodium chloride;
5) sodium.
104. Chemical elements are arranged in order of increasing electronegativity in
1) Si, P, Se, Br, Cl, O;
2) Si, P, Br, Se, Cl, O;
3) P, Si, Br, Se, Cl, O;
4) Br, P, Cl, Si, Se;
5) Si, P, Se, Cl, O, Br
105. The valence orbitals of the beryllium atom in the beryllium hydride molecule ... are hybridized
106. The beryllium hydride molecule has the structure:
1) square
Flat
3) tetrahedral
5) spherical.
107. The valence orbitals of the boron atom in the BF 3 molecule are hybridized as follows:
108. Which molecule is the strongest?
109. Which of the following molecules has the largest dipole?
110. What spatial configuration does the molecule have during sp 2 hybridization of AO:
1) linear
2) tetrahedron
3) flat square
Flat trigonal
111. The molecule has an octahedral structure if the following hybridization occurs
3) d 2 sp 3
112. The modern theory of atomic structure is based on the concepts of:
1) classical mechanics;
3) Bohr's theory;
4) electrodynamics;
5) chemical kinetics.
113. Of the following, the characteristics of atoms of elements change periodically:
1) charge of the atomic nucleus
2) relative atomic mass;
3) the number of energy levels in an atom;
4) number of electrons at the outer energy level;
5) total number electrons.
114. Within a period, an increase in the serial number of an element is usually accompanied by:
1) a decrease in the atomic radius and an increase in the electronegativity of the atom;
2) an increase in the atomic radius and a decrease in the electronegativity of the atom;
3) a decrease in atomic radius and a decrease in the electronegativity of the atom
4) an increase in atomic radius and an increase in the electronegativity of the atom
5) a decrease in electronegativity.
115. The atom of which element gives up one electron most easily:
1) sodium, serial number 11;
2) magnesium, serial number 12;
3) aluminum, serial number 13;
4) silicon, serial number 14;
5) sulfur, serial number 16.
116. Atoms of elements of group IA of the periodic system of elements have the same number:
1) electrons at the outer electronic level;
2) neutrons;
3) all electrons;
4) electronic shells;
5) protons.
117. Which of the following elements is named after the country:
118. Which series includes only transitional elements:
1) elements 11, 14, 22, 42;
2) elements 13, 33, 54, 83;
3) elements 24, 39, 74, 80;
4) elements 19, 32, 51, 101;
5) elements 19, 20, 21, 22.
119. The atom of which of the VA group elements has the maximum radius:
2) phosphorus;
3) arsenic;
4) bismuth;
5) antimony.
120. Which series of elements is presented in order of increasing atomic radius:
1) O, S, Se, Te;
3) Na, Mg, AI, Si;
4) J, Br, CI, F;
5) Sc, Te, V, Cr.
121. Metallic character of the properties of elements in the series Mg – Ca – Sr – Ba
1) decreases;
2) increases;
3) does not change;
4) decreases and then increases;
5) increases and then decreases.
122. Basic properties of hydroxides of elements of the JA group as the atomic number increases
1) decrease,
2) increase,
3) remain unchanged,
4) decrease and then increase,
5) increase and then decrease.
123. Simple substances of which elements have the greatest similarity of physical and chemical properties:
3) F, CI;
124. The existence of which of the following elements was predicted by D.I. Mendeleev:
3) Sc, Ga, Ge;
125. What distinguishes large periods from small ones:
1) the presence of alkali metals;
2) absence of inert gases;
3) the presence of d- and f-elements;
4) the presence of non-metals;
5) the presence of elements with metallic properties.
126.How to determine the period in which a given element is located using the electronic formula of an element:
1) by the value of the principal quantum number of the external energy level;
2) by the number of valence electrons;
3) by the number of electrons in the external energy level;
4) by the number of sublevels in the external energy level;
5) by the value of the sublevel where the last valence electron is located.
127. Which element has the lowest ionization potential:
128. A chemical element of the third period forms a higher oxide of composition E 2 O 3. How are electrons distributed in an atom of a given element?
1) 1s 2 2s 2 2p 1
2) 1s 2 2s 2 2p 6 3s 1
3) 1s 2 2s 2 2p 6 3s 2 3p 1
4) 1s 2 2s 2 2p 6 3s 2 3p 6
5) 1s 2 2s 2 2p 3
129.Which chemical element forms the base with the most pronounced properties
1) calcium
3) aluminum
Potassium
5) beryllium
130. A chemical element has the following distribution of electrons across the electron layers in the atom 2.8.6. What position does it occupy in the periodic table of chemical elements D.I. Mendeleev:
1) 6th period 6th group
Period 6 group
3) 2nd period 6th group
4) 3rd period 2nd group
5) 2nd period 8th group
131. The quantum numbers of the last electron in an element’s atom are n = 5, l = 1, m = -1, m s = - . Where is this element located on the periodic table?
1) 5th period, first group
2) 5th period, main subgroup of 4th group
3) 4th period, sixth group
period, sixth group main subgroup
5) 5th period, sixth group - secondary subgroup.
132. Formula of the highest oxide of the chemical element EO 2. Which group of the main subgroup of the periodic system of chemical elements belongs to D.I. Does this element belong to Mendeleev?
Fourth
5) sixth.
133. From the given list of elements - Li, Na, Ag, Au, Ca, Ba - alkali metals include:
1) all metals;
2) Li, Na;
3) Li, Na, Ag, Au;
134. In the series from Li to Fr:
1) metallic properties are enhanced;
2) metallic properties decrease;
3) the atomic radius decreases;
4) the connection of valence electrons with the nucleus is enhanced;
5) activity towards water decreases
135. The sequence of elements does not apply to metals:
3) B, As, Te;
136. With increasing atomic number of the element, the acidic properties of the oxides N 2 O 3 - P 2 O 3 - As 2 O 3
Sb 2 O 3 - Bi 2 O 3
1) intensify;
2) weaken;
3) remain unchanged;
4) strengthen, then weaken;
5) weaken, then strengthen.
137. The ammonia molecule has the form:
1) curved;
2) linear;
3) planar;
4) pyramidal;
138. In the series C-Si-Ge-Sn-Pb, non-metallic characteristics of the elements:
1) increase;
2) weaken;
3) do not change;
4) increase and then decrease;
5) weaken and then increase.
139. The valence orbitals of the carbon atom in the CH4 methane molecule can be described based on
ideas about hybridization type (sp; sp 2; sp 3; d 2 sp 3; dsp 2).
In this case, the methane molecule has the form:
1) linear;
2) flat;
3) tetrahedral;
5) square.
140. The valence orbitals of the silicon atom in the SiH 4 silane molecule can be described based on the concept of hybridization of the type (sp; sp 2 ; sp 3 ; d 2 sp 3 ; dsp 2).
Therefore, the silane molecule has the form:
1) linear;
2) flat;
3) tetrahedral;
5) square.
141.What is the maximum number of covalent bonds that a nitrogen atom can form:
142. The nitrogen atom of an ammonia molecule with a hydrogen ion forms:
1) ionic bond;
2) covalent bond by exchange mechanism;
3) non-polar covalent bond;
4) covalent bond through the donor-acceptor mechanism;
5) hydrogen bond.
143. Which statement is false:
4) Ionic bonding is saturable;
144. Which statement is false:
1) The covalent bond is saturable;
2) The covalent bond has directionality;
3) The ionic bond is unsaturable;
4) The ionic bond is directional;
5) The ionic bond is non-directional.
“Patterns chemical processes and their energy"
145. What changes in temperature T and pressure P contribute to the formation of CO according to the reaction C(solid) + CO 2 (g) 2CO (g) -119.8 kJ:
1) increase in T and increase in P;
2) increase in T and decrease in P;
3) decrease in T and increase in P;
4) decrease in T and decrease in P;
5) increase in R.
146. How many times will the rate of a chemical reaction increase when the temperature increases by 30 0, if the temperature coefficient of the rate is 2?
147. How many degrees must the temperature be lowered so that the reaction rate decreases by 27 times, if the temperature coefficient of the rate is 3?
148. How many times will the reaction rate X+ 2Y = Z increase with increasing concentration
Y 3 times?
149. How many times will the rate of the forward reaction increase compared to the rate of the reverse reaction in the 2NO + O 2 2NO 2 system when the pressure doubles?
150. Specify the correct expression for the speed for the system: 2Cr+3Cl 2 = 2CrCl 3
5) v= k[A][C].
154. A catalyst speeds up a chemical reaction due to:
1) decrease in activation energy;
2) increasing the activation energy;
3) reducing the heat of reaction;
4) increasing concentration;
5) all answers are incorrect.
155. The equilibrium of the reaction Fe 3 O 4 +4CO «3Fe +4CO 2 -43.7 kJ shifts to the left:
1) when the temperature drops;
2) with increasing temperature;
3) with increasing pressure;
4) with increasing concentration of starting substances;
5) when adding a catalyst.
156. How many times will the rate of a chemical reaction increase when the temperature increases by 30 0, if the temperature coefficient of the rate is 3?
157. How many degrees must the temperature be increased for the reaction rate to increase 27 times, if the temperature coefficient of the rate is 3?
158. How many times does the rate of reaction X+2Y=Z increase when the concentration of X increases by 3 times?
159. How many times will the rate of the forward reaction increase compared to the rate of the reverse reaction in the 2CO+O 2 2CO 2 system when the pressure doubles?
160. How will the rate of the gas reaction 2NO 2 =N 2 O 4 increase with an increase in the concentration of NO 2 by 5 times?
161. How many times will the rate of the gas reaction 2NO+O 2 =2NO 2 decrease when the mixture of reacting gases is diluted 3 times?
162. How many degrees must the temperature be lowered so that the reaction rate decreases by 81 times at a temperature coefficient of 3?
163. How many times will the rate of reaction 2NO+O 2 =2NO 2 increase when the pressure in the system increases by 4 times?
164. How many times will the rate of the forward reaction increase compared to the rate of the reverse reaction in the 2NO+O 2 2NO 2 system when the pressure in the system increases by 5 times?
165. How will the rate of the reaction 2SO 2.g + O 2.g 2SO 3.g change with increasing concentration 1) will increase 3 times; 2) will increase 9 times; 3) will decrease by 3 times; 4) will decrease by 9 times; 5) will not change. 166. How will the rate of the reaction 2O 3.g 3O 2.g change when the pressure doubles? 1) will decrease by 2 times; 2) will decrease by 8 times; 3) will increase 4 times; 4) will decrease by 4 times; 5) will increase by 2 times. 167. How will the rate of the reaction 2NO g + O 2.g 2NO 2.g change with a simultaneous decrease concentration of NO and O 2 2 times? 1) will increase by 2 times; 2) will decrease by 2 times; 3) will increase by 2 4 times; 4) will decrease by 2 4 times; Will decrease by 8 times. 168. How will the rate of the direct reaction H 2 O, g H 2, g + O 2, g change if the pressure in the system increases 4 times? 1) will increase by 2 times; 2) will decrease by 2 times; 3) will not change; 4) will increase 4 times; 5) will decrease by 4 times. 169. The law of mass action was discovered: 1) M.V. Lomonosov 2) G.I. Hessom 3) J.W. Gibbs K. Guldberg and P. Waage 5) Van't - Hoff 170. Which of the following systems is homogeneous Sodium chloride solution 2) ice water 3) saturated solution with sediment 4) coal and sulfur in the air atmosphere 5) a mixture of gasoline and water 171. The value of the rate constant of a chemical reaction does not depend 1) from the nature of the reacting substances 2) on temperature 3) from the presence of catalysts From the concentration of substances 5) from any factors 172. Activation energy is 1) the energy required to remove an electron from an atom 2) the excess energy that molecules must have per 1 mole in order for their collision to lead to the formation of a new substance 3) ionization potential 4) energy that is released as a result of the reaction 5) energy that is released when an electron attaches to an atom. 173. The increase in reaction rate with increasing temperature is usually characterized by: 1) rate constant of a chemical reaction 2) chemical equilibrium constant Topic: SECOND GROUP OF THE PERIODIC SYSTEM 1 Characteristics. Atoms of elements of group 2 of the periodic table in the outer electron layer have 2 electrons located at a considerable distance from the nucleus. Therefore, these 2 electrons are relatively easily split off from atoms, which turn into positive doubly charged ions. The difference in the structure of the second outer layer of a number of elements of the second group determines the existence of two subgroups: the main one, including alkaline earth metals (beryllium, magnesium, calcium, strontium, barium, radium) and a secondary subgroup, including the elements: zinc, cadmium and mercury. All elements included in the main subgroup, except beryllium and radium, have pronounced metallic properties. The higher the atomic mass, the more electropositive the metal. Thus, barium is as strong a reducing agent as the alkali metals. With water, oxides of alkaline earth metals form hydroxides, the solubility of which increases from beryllium hydroxide to barium hydroxide. The basic character of these compounds increases in the same sequence. The elements of the side subgroup (Zn, Cd, Hg), as well as the elements of the main subgroup, exhibit an oxidation state of +2, but there is also a difference between them due to the different sizes of the radii of their atoms and ionization potentials. The metallic properties of elements of the secondary subgroup weaken from zinc to mercury. Their hydroxides are insoluble in water and have weakly basic properties. The elements of interest for medicine are Mg, Ca, Ba, Zn and Hg. All these elements are part of the structure of the most important drugs. The most toxic of the group II elements is barium in its soluble compounds, which are used only as reagents and poisons for insects and rodents. In medicine, barium sulfate, a salt practically insoluble in any solvent, is used mainly. 2. MAGNESIUM COMPOUNDS Magnesium is widely distributed in nature. It is not found in free form, but only in the form of carbonate compounds, forming minerals dolomite MgC0 3 *CaCO 3 and magnesite MgC0 3.. Magnesium is part of silicates - talc 3MgO*4Si0 2 *H 2 0, etc. Magnesium salts are also found in soil, natural waters, especially sea waters, and many mineral springs. The value of magnesium is great. It is part of the green plant pigment - chlorophyll, participating in the process of plant photosynthesis. Magnesium compounds play a significant role in the activity of the central nervous system of living organisms. According to its physiological action, magnesium is a calcium antagonist. So, if magnesium salts cause anesthesia and paralysis, then calcium compounds relieve this phenomenon. On the contrary, the effect exerted by calcium compounds is removed by magnesium. Pharmacopoeial preparations of magnesium are: magnesium oxide, burnt magnesia, basic magnesium carbonate, white magnesium, Magnesium trisilicate, magnesium sulfate. The first three drugs exhibit an antacid effect, i.e. they are used for increased acidity of gastric juice. They act in the same way as very mild laxatives. Magnesium sulfate is used as a sedative, antispasmodic and laxative. Magnesium sulfate Magnesii sulfas MgS0 4- 7H 2 0 M. m. 246.50 Magnesium sulfate as a remedy was first used in England - Epsom or bitter salt. A) Receipt. Magnesium sulfate is distributed in nature in the form of kieserite MgS0 4 *7H 2 0. Magnesium sulfate is found in large quantities in sea water. A preparation is obtained from magnesite MgC0 3
by treating it with sulfuric acid. MgCO 3 + H 2 S0 4 > MgS0 4 + C0 2 + H 2 O The resulting solution is concentrated by evaporation until crystallization, resulting in MgS0 4 *7H 2 0. B) Properties. Colorless prismatic crystals, weathering in air, salty-bitter taste, odorless. It is highly soluble in water, practically insoluble in alcohol. B) Authenticity GF - for Mg 2+ , the formation of a precipitate of double ammonium and magnesium phosphate when interaction of the drug with dibasic sodium phosphate in an ammonia solution in the presence of ammonium chloride. MgS0 4 + Na H P0 4 + NH 4 OH = MgNH 4 P0 4 + Na 2 S0 4 + H 2 0 White If this reaction is carried out using the drop method on a glass slide, crystals of a certain shape are formed, which can serve as confirmation of the authenticity of the drug. GF - With organic rheu-8-hydroxyquinoline, in the presence of an ammonia solution with the addition of ammonium chloride NH 4
C1 produces magnesium hydroxyquinolate, colored greenish-yellow. GF - The sulfate ion opens with a solution of barium chloride a white milky precipitate of barium sulfate precipitates. Insoluble in acids and alkalis. MgS 0 4 + BaС1 2 = Mg С1 2 + BaS 0 4 D) Cleanliness . Allowed are arsenic no more than 0.0002%, chlorides, heavy metals, moisture. The preparation used for injection Solutio Magnesii sulfatis 20% aut 25% pro injectionibus is tested for manganese. GF complexometric titration method. An ammonia buffer solution and a special acid chromium black special indicator are added to the drug solution and titrated with Trilon B until the red color turns blue. D.b. 99% -102% E) Application. Myotropic antispasmodic, laxative. Used as a laxative, 15 x 30 g per oral dose. When administered parenterally, magnesium sulfate has a calming effect on the central nervous system. As an antispasmodic hypertension in the form of a 25% solution (subcutaneously); For labor pain relief, 10 x 20 ml of 25% solution intramuscularly; As an anticonvulsant in the same doses “as for pain relief in childbirth; As a choleretic agent, 20 x 25% solution (orally). In case of respiratory depression associated with overdose (curarepod), a 10% calcium chloride solution is used intravenously. Release: powder, 10%, 20%, 25% solution in ampoules, 2.5, 10 and 20 ml. Powder in bags 10.0-50.0. Cormagnesin, 32% magnesium-Diasporal forte g) Storage: dry, cool place. 3. CALCIUM COMPOUNDS Calcium is widely distributed in nature. Due to its high chemical activity, it is found in nature only in a bound state. It occurs in the form of numerous deposits of limestone, chalk and marble - these are natural varieties of calcium carbonate CaCO3. Gypsum CaS0 is also found 4 -2H 2 0, phosphorite Ca 3 (P0 4) 2 and silicates. All natural calcium compounds, especially carbonates, serve as sources for medical calcium preparations; marble is often used as the purest. Calcium plays an important role in the functioning of the body. It is part of dental tissue, bones, nervous tissue, muscles, and blood. Calcium ions enhance the vital activity of cells, promote the contraction of skeletal muscles and heart muscles, and are necessary for the formation bone tissue and the blood clotting process. With a decrease in the concentration of calcium ions in the blood, muscle excitability increases, which often leads to cramps. Solutions of calcium salts relieve itching caused by an allergic condition, so they are classified as antiallergic drugs. Of the calcium compounds used in medicine, calcium oxide (burnt lime), burnt calcium sulfate (burnt gypsum), precipitated calcium carbonate (precipitated chalk), calcium chloride and salts of organic acids (calcium glycerophosphate, calcium gluconate, etc.). The pharmacopoeial drug is calcium chloride. Calcium chloride Calcii chloridum CaC1 2 -6H 2 0 M. m. 219.08 A) Receipt. Calcium chloride, intended for medical purposes, is obtained by treating calcium carbonate (marble) with hydrochloric acid. CaCO 3 + 2HC1 = CaCl 2 + C0 2 + H 2 O Pure calcium chloride CaCl crystallizes from water 2 -6Н 2 0. B) Properties. They are colorless, odorless prismatic crystals with a bitter-salty taste; very easily soluble in water, causing a strong cooling of the solution. Easily soluble in 95% alcohol. The drug is very hygroscopic and dissolves in air. At a temperature of 94°C it melts in its water of crystallization. Aqueous solutions have a neutral reaction. When heated to 200°C, it loses part of its water of crystallization and turns into calcium chloride dihydrate CaCl1 2 -2H 2 0, The hygroscopicity of the drug and its ability to dissolve under the influence of moisture make the composition of this salt inconsistent, which can lead to inaccurate dosage when preparing drugs with calcium chloride. Taking this into account, pharmacies prepare a 50% solution of it (Calcium chloratum solutum 50%) and the necessary drugs are prepared from this concentrate. B) Authenticity: GF - reaction to Ca 2+ reaction with ammonium oxalate, (NH 4 ) 2 C 2 0 4 + CaC 1 2 = CaC 2 0 4 + 2NH 4 Cl White sediment The precipitate is soluble in mineral acids and insoluble in acetic acid. Formation of a white precipitate when the drug interacts with sulfuric acid or alkali metal sulfates. CaCl 2 + H 2 S0 4 = CaS0 4 + 2HC1 White sediment The calcium sulfate precipitate dissolves in ammonium sulfate to form a colorless complex. GF- calcium salts color the burner flame brick red. GF for chlorides with silver nitrate CaCl 2 + Ag N O 3 = Ag Cl + Ca (N O 3 ) 2 White curdled sediment D) Cleanliness . Impurities of soluble salts of barium, iron, aluminum, and phosphates are not allowed in the preparation. Sulfates, heavy metals, arsenic, and magnesium salts according to standards are allowed. D) Quantitative definition GF - determined complexometrically with the indicator acid chromium dark blue. When titrating with Trilon B, when adding an ammonia buffer solution, the color of the solution changes from cherry-red to bluish-lilac (indica eriochrome black special T). Must be at least 98.0%. Photometric, - argentometry (Mora) Fluorometric, - refractometry By weight (oxalate). E) Application. Antiallergic As a hemostatic agent for pulmonary, gastrointestinal, nasal and uterine bleeding; In surgical practice to increase blood clotting; For allergic diseases (bronchial asthma, urticaria) to relieve itching; As an antidote for poisoning with magnesium salts. Anti-inflammatory, for colds The drug is prescribed orally in the form of a 5 x 10% solution, intravenously as a 10% solution. It cannot be administered subcutaneously or intramuscularly, as in this case necrosis may occur. Release form: powder, 10% solution in ampoules. g) Storage. In small, well-sealed glass jars with a stopper, filled with paraffin, in a dry place. 4. ZINC COMPOUNDS In nature, zinc occurs in the form of minerals: gallite ZnCO 2
and zinc blende ZnS. Zinc is found in muscle, dental and nervous tissue of the human body. The use of zinc compounds in medicine is based on the fact that zinc produces compounds with proteins - albuminates, soluble albuminates have an effect ranging from weakly astringent to cauterizing. Insoluble albuminates usually form a film on the tissue surface and thus promote tissue healing (drying effect). Zinc compounds are toxic in large doses; when applied topically, they can be used as astringents and cauterizing agents. When administered orally, zinc compounds cause vomiting. Pharmacopoeial preparations of zinc are zinc oxide and zinc sulfate. Zinc sulfate Zinci sulfas ZnSO4 *7H 2 0 M. m. 287.54 Zinc sulfate has been used in medicine since ancient times under the name of white sulfate, in contrast to colored copper and iron sulfate. A) Receipt. From natural ore zinc blende ZnS, which is roasted. In this case, zinc sulfide is converted into an oxide, which is then treated with dilute sulfuric acid, resulting in the formation of zinc sulfate in solution. 2 ZnS + ZO 2 = 2 ZnO + 2 SO 2 ZnO + Ha 2 S 0 4 = ZnS 0 4 + 4 H 2 O A solution containing zinc sulfate is evaporated until the salt crystallizes in the form of heptahydrate (ZnS0 4 -7H 2 0). B) Properties. Colorless transparent crystals or finely crystalline powder, having an astringent metallic taste, odorless, very easily soluble in water, slowly in glycerin, insoluble in alcohol. It erodes in the air. B) Authenticity. GF - Sulfate ion is determined by the formation of a white precipitate. ZnS0 4 + Ba Cl 2 = Ba S0 4 + Zn Cl 2 White milky, insoluble in acids and alkalis GF- on Zn 2+ reaction with a solution of sodium sulfide produces white zinc sulfide ZnS (different from other heavy metal salts). ZnS0 4 +Na 2 S = ZnS 4 + Na 2 S0 4 White sediment GF - Zn 2+ reaction with a solution of potassium ferrocyanide a white-yellowish crystalline precipitate of a double salt is formed, insoluble in acids, but soluble in alkalis. 3 ZnS 0 4 + 2 K 2 [Fe (CN) 6] = K 2 Zn 3 [Fe (CN) 6] 2 + 3 K 2 SO 4 White-yellowish A specific reaction to zinc is the formation of Rinman green. ZnS 0 4 drop onto filter paper and add cobalt nitrate on top, calcinate, this results in a characteristic green color – Rinman green: CoZnO2 With dithizone ions Zn 2+ in an alkaline environment they form a red color. D) Cleanliness . Not d.b. impurities of iron, copper, aluminum, magnesium, calcium and other heavy metals. Arsenic admixture is allowed D) Quantification GF complexometry. In the presence of an ammonia buffer solution and an acid indicator, special black chrome (or eriochrome black T). Titrate with Trilon B until the color of the solution changes from cherry-red to bluish-lilac. E) Application externally as an antiseptic and astringent In ophthalmic practice in the form of 0.1; 0.25; 0.5% solutions. In eye drops, zinc sulfate is often prescribed along with boric acid.
In gynecological practice for douching in the form of a 0.1 x 0.5% solution. For skin diseases: acne, acne, dermatoses. Rarely prescribed orally as an emetic. Release forms: powder, eye drops 0.1; 0.25; 0.5%, drops of zinc sulfate with boric acid. Combined: Zinkin, Zincteral g) Storage. With caution in well-sealed jars. List B. Zinc oxide Zinci oxydum It is a white amorphous powder with a yellowish tint that easily absorbs carbon dioxide from the air. A characteristic property of zinc oxide is that when heated, it becomes yellow, and when cooled, it becomes white. Zinc oxide is used externally in the form of powders, ointments, linements as an astringent, drying and disinfectant for skin diseases: dermatitis, prickly heat, bedsores, diaper rash, ulcers, wounds, burns. 5. MERCURY COMPOUNDS Mercury is a liquid metal. The distribution of mercury in nature is low. It is found in native form, disseminated in rocks, but mainly in the form of mercury sulfide HgS (cinnabar) of a bright red color. Pharmacopoeial drugs are mercury compounds having an oxidation state of +2: mercury yellow oxide, mercury dichloride, mercury amide chloride, mercury oxycyanide and mercury cyanide. Inorganic mercury preparations are used as antiseptic, diuretic and laxatives. The antiseptic effect of mercury compounds is based on the ability of the mercury ion to precipitate proteins. The diuretic effect of some mercury salts is associated with in that, when excreted through the kidneys, they irritate the renal epithelium and promote urination. Similarly, mercury compounds, released through the intestines and irritating it, exhibit a laxative effect. Soluble mercury salts are very toxic and belong to list A. Mercury oxide yellow Hydrargyri oxydum flavum HgO M. m. 216.59 A) Receipt . Precipitation reactions from soluble mercury salts are used. For this purpose, mercuric dichloride or nitrate is most often used. A concentrated solution of mercury (II) salt is slowly poured into a dilute alkali solution. Hg(NO 3 ) 2 + 2NaOH = 2NaNO 3 + HgO + H2O Bright yellow sediment After the mercury oxide precipitate has settled, the liquid is drained, the precipitate is washed until there is no alkaline reaction and dried. All operations should be carried out in the dark, otherwise mercuric oxide Hg may be formed 2 0 black. B) Properties. Heavy fine powder of yellow or orange-yellow color. Insoluble in water, but easily soluble in hydrochloric, nitrogen and acetic acids. The light gradually darkens. B) Authenticity for Hg2+. To do this, it is treated with diluted hydrochloric acid to obtain a soluble mercury (II) salt, in which the Hg cation is determined 2+
HgO + 2HC1 = HgCl 2 + H.0 GF - reaction with alkali solutions, a precipitate of yellow mercury oxide precipitates. HgCl 2 + 2KOH > HgO + 2KS + H 2 0 Bright yellow sediment GF - reaction with potassium iodide solution; A bright red precipitate of mercury diiodide is formed, which dissolves in excess potassium iodide. HgCl 2 + 2Kl = HgJ 2 + 2KCl HgJ 2 + 2KI > K 2 Bright red colorless solution A solution of this complex salt is known as Nessler's reagent and is used as a very sensitive reagent for NH 4+;
GF - reaction with sodium sulfide solution; a brown-black precipitate is formed, insoluble in dilute nitric acid. HgCl 2 + NaS = HgS + 2NaCl Brownish-black sediment D) Quantitative content GF - neutralization indirectly through interaction with potassium iodide. When yellow oxide is exposed to mercury with a solution of potassium iodide, a soluble complex salt and alkali are formed, which is titrated with acid against methyl orange HgO + 4 KI + H 2 O > K 2 [Hgl 4 ] + 2KOH KON +NS1 = KS1 + N 2 0 Rhodanometric method: yellow mercuric oxide is dissolved in nitric acid, and the resulting salt is titrated with ammonium thiocyanate in the presence of ferroammonium alum until it turns red. G) Application as a gentle antiseptic for the preparation of eye ointments 2%. E) Store should be taken with caution in well-sealed dark glass jars, since mercuric oxide may form in the light, which is detected by the darkening of the preparation. List B. Topic FIRST GROUP OF THE PERIODIC SYSTEM 1.Characteristics.All elements that make up the first group of the periodic table have only an I electron in their outer electron layer, which they easily give up, turning into singly charged positive ions. This explains their very high reactivity towards electronegative elements such as halogens. The main subgroup includes lithium, sodium, potassium, rubidium, cesium and francium. The side group consists of copper, silver and gold. The elements of the main subgroup are called alkali metals, since their oxides, when interacting with water, form strong alkalis. Alkali metal salts are used in medicine. The most widely used in medicine are sodium and potassium salts, described above in preparations derived from halogens. 2. COMPOUNDS OF COPPER AND SILVER A secondary subgroup of elements of the first group consists of copper, silver and gold. They have a tendency to form complexes, especially copper, and also the ability to be reduced from compounds to free metal, with silver being reduced more easily than copper. Of the inorganic copper compounds, copper sulfate is used in medicine. When taken orally, it has an emetic effect; as an external remedy it is used for catarrh of the mucous membranes and ulcers due to its astringent, irritating and cauterizing effect. Silver belongs to the “noble” metals. In nature, it occurs mainly in the form of compounds with sulfur (Ag 2 S). The use of silver preparations in medicine is based on its bactericidal properties. It has been proven that silver ions kill gram-positive and gram-negative microorganisms, as well as viruses. Silver preparations are used in medicine internally and externally as astringent, antiseptic and cauterizing agents in the treatment of skin, urological and eye diseases. Of the silver compounds, the most widely used is silver nitrate (AgN03), as a good astringent and cauterizing agent. In medicine, colloidal preparations are also used, where silver is bound to protein and is only partially ionized. In colloidal silver preparations, only the disinfecting properties of silver are retained and its cauterizing effect disappears. All soluble copper and silver compounds are poisonous. 3. Silver nitrate Argenti nitras AgN0 3 A) Receipt by dissolving a copper-silver alloy in nitric acid when heated. To clean the resulting silver nitrate from impurities, it is precipitated with hydrochloric acid in the form of silver chloride. The latter is reduced with zinc, and silver, freed from impurities, is again dissolved in nitric acid. The resulting silver nitrate is treated with a small amount of water, and crystals crystallize when standing. The isolated crystals are filtered, washed with water and dried in the dark. B) Properties colorless transparent crystals in the form of plates or cylindrical rods of a radiant-crystalline structure in a fracture. Easily soluble in water, difficult in alcohol. Crystals darken in light. B) Authenticity GF - Ag+ : with hydrochloric acid or its salts a white precipitate of silver chloride precipitates, insoluble in nitric acid and highly soluble in ammonia solution AgNO 3 + HCl = AgCI + HNO 3 White AgCl + 2NH 4 0H = Cl + 2H 2 O GF - Ag+ reduction to free silver (reaction of formation of a silver mirror). A solution of formaldehyde is added to the ammonia solution of silver oxide and the liquid is heated. After some time, a coating of metallic silver in the form of a mirror forms on the walls of the vessel. [ Ag (NH 3 ) 2 ] OH + HSON = 2Ag + HCOOH + 4 NH 3 + 2 H 2 O Black sediment Ag+ with potassium chromate, a brownish-red precipitate of silver chromate precipitates. 2AgNO 3 + K 2 Cr0 4 = Ag Cr0 4 + 2KNO 3 Brownish-red precipitate The precipitate is soluble in nitric acid, ammonium hydroxide, and sparingly soluble in acetic acid. GF - Nitrate ion determined with diphenylamine in con. Sulfuric acid produces a blue color Formation of a brown ring when silver nitrate reacts with ferrous sulfate in concentrated sulfuric acid. Nitrate ion Potassium permanganate does not discolor in an acidic environment, unlike nitrite. D) Cleanliness allowable acidity limit Salts of heavy metals (lead, copper, bismuth) are not allowed. D) Quantitativecontent - Volhard precipitation method, titrated with ammonium thiocyanate (rodanide) AgNO 3 + NH 4 SCN = AgSCN + NH 4 NO, White sediment 3NH 4 SCN + (NH 4 )Fe(S0 4 )= Fe(SCN) 3 + 2(NH 4 ) 2 S0 4 The indicator is ferroammonium alum until it turns red. D.b. less than 99.75%. G) Application antiseptic and cauterizing. The latter is due to the ability of silver nitrate to coagulate proteins, turning them into insoluble compounds, which is used to cauterize wounds and ulcers. For this purpose, silver nitrate in the form of sticks (Stilus Argenti nitrici) is used. In small concentrations it has an astringent and anti-inflammatory effect. Used externally for erosions, ulcers, acute conjunctivitis, trachoma in the form of 2510% aqueous solutions, as well as ointments (12%). It is prescribed orally in the form of a 0.05 x 0.06% solution for gastric ulcers and chronic gastritis. Release form: powder, lapis sticks. IRR orally 0.03 g, IRR 0.1 E) Storage in well-sealed dark glass jars, since it can decompose in the light, which is detected by the darkening of the drug. List A. 4. Protargol Protargolum, Argentum proteinicum Silver proteinate A) Receipt from silver nitrate and protein (casein, gelatin, egg white, peptone) Protected colloid: contains silver oxide (7.8 x 8.3%) and albumin hydrolysis products. B) Properties Light amorphous yellow-yellow powder Brown, odorless, slightly bitter, slightly astringent taste. Easily soluble in cold water, insoluble in alcohol. B) Authenticity GF- Protein is determined by the appearance of the smell of burnt horn and the charring of the preparation when heated. GF- the residue from combustion (it is white) is dissolved in HNO 3
and carry out reactions on Ag+ with chlorides. - (biuret re-I) the drug is boiled with dil. HCl, a precipitate forms, it is filtered and NaOH and C are added to the clear filtrate uS O 4, A violet color appears (on protein). D) Cleanliness not d.b. impurities of silver compounds, protein decomposition products. D) Quantitativedefinition: after ashing the preparation with sulfuric acid. Argentometry method, Volhard version. D.b. 7.88.3% G) Application Antibacterial, anti-inflammatory agent. Used externally in ophthalmology 1-2% solution (conjunctevitis, blenorrhea, blepharitis), urology 0.1-1% (bladder lavage), otorhinolaryngology (ears, nose), gynecology. Orally for stomach ulcers and intestinal diseases. Release form: powder and dosage form in pharmacies. E) Storage : according to list B. In well-closed dark glass jars 5. Collargol (Collargolum, Argentum colloidale, Silver colloid) Colloidal system with 70-75% content of highly dispersed metallic silver and protective proteins (hydrolysates of casein and gelatin). Greenish-black or bluish-black plates with a metallic sheen, soluble in water to form a colloidal solution. When treated with water, it swells and forms alkaline, negatively charged sols. Antibacterial agent. Apply: 0.2 1% solutions for washing purulent wounds; 1 2% solutions for washing the bladder for chronic cystitis and urethritis, 2 x 5% solutions in the form of eye drops for the treatment of purulent conjunctivitis and blenorrhea. For erysipelas and chancre, 15% ointment is sometimes prescribed. Rarely in septic conditions: intravenous administration. Storage: according to list B. In well-closed dark glass jars “Names of chemical elements” - “Only perseverance and hard work can achieve results.” Other names are directly related to the myths of the ancient Greeks. DI. Mendeleev. Goals. Author of the presentation. Have fun!!! Dear Guys! Lead. K. Fill in the crossword cells with Russian names of the following chemical elements: 1. Cl. 2. Zn. 3. Br. 4. K. 5. Ni. “Elements of Statistics” - To calculate the number of intervals, the Sturgers formula is recommended r? 1+3.322 lg n The length of the interval is calculated by the formula: h = (xmax-xmin)/r. “Statistical thinking will eventually become as necessary as writing and reading skills.” Basic concepts. Having registered the duration of work 65 vacuum tubes, got the following results: "Chemical properties" - Chemical properties salts Genetic relationships between classes of inorganic compounds. Assignments from the Unified State Exam in chemistry. Classification of acids. Classes of inorganic compounds. Classification of bases. A = N + P A chemical element is a type of atom with a certain nuclear charge. Test your knowledge. The structure of the atom. Definition. “Periodic Table of Chemical Elements” - Programmed work using punched cards. Dmitry Ivanovich Mendeleev 1834-1907. A living world is happening around you. Find out "Tell me about me" station. Test yourself: 12-14 points – “4” - yellow trailer. A. 35 B. 44 C. 45 D. 80 3. What is the mass number of a copper atom? 5 correct answers – “3” points. A. 2 B. 3 C. 5 D. 11. “Chemical agents” - Hydrophilic “head”. Obtained from animal and vegetable fats, naphthenic acids, rosin, tall oil. Therefore, potassium hydroxide is also called potassium hydroxide. A solution of sodium hydroxide in water is soapy to the touch and very caustic. Take care environment and your health. Preface. Chemicals at home. “Elements of combinatorics” - What are placements? Write down a formula to find the number of combinations? What is factorial? Lesson topic: “elements of combinatorics” (workshop). Let there be n elements and you need to select some k elements one by one. Selection of combinatorial problems. Write down the formula to find the number of placements? The main subgroup of group II of the Periodic Table of elements consists of beryllium Be, magnesium Mg, calcium Ca, strontium Sr, barium Ba and radium Ra. Table 18 – Characteristics of elements 2Ап/group The atoms of these elements have two s-electrons at the outer electronic level: ns 2. In chem. In reactions, atoms of elements of the subgroup easily give up both electrons of the outer energy level and form compounds in which the oxidation state of the element is +2. All elements of this subgroup belong to metals. Calcium, strontium, barium and radium are called alkaline earth metals. These metals are not found in a free state in nature. The most common elements include calcium and magnesium. The main calcium-containing minerals are calcite CaCO 3 (its varieties are limestone, chalk, marble), anhydrite CaSO 4, gypsum CaSO 4 ∙ 2H 2 O, fluorite CaF 2 and fluorapatite Ca 5 (PO 4) 3 F. Magnesium is part of magnesite minerals MgCO 3, dolomite MgCO 3 ∙ CaCo 3, carnallite KCl ∙ MgCl 2 ∙ 6H 2 O. Magnesium compounds in large quantities found in sea water. Properties. Beryllium, magnesium, calcium, barium and radium are silvery-white metals. Strontium has a golden color. These metals are light; calcium, magnesium, and beryllium have especially low densities. Radium is a radioactive chemical element. Beryllium, magnesium and especially alkaline earth elements are reactive metals. They are strong reducing agents. Of the metals of this subgroup, beryllium is somewhat less active, which is due to the formation of a protective oxide film on the surface of this metal. 1. Interaction with simple substances. All easily react with oxygen and sulfur, forming oxides and sulfates: 2Be + O 2 = 2BeO Beryllium and magnesium react with oxygen and sulfur when heated, other metals - under normal conditions. All metals in this group react easily with halogens: Mg + Cl 2 = MgCl 2 When heated, all react with hydrogen, nitrogen, carbon, silicon and other non-metals: Ca + H 2 = CaH 2 (calcium hydride) 3Mg + N 2 = Mg 3 N 2 (magnesium nitride) Ca + 2C = CaC 2 (calcium carbide) Calcium caribite is a colorless crystalline substance. Technical carbite, containing various impurities, can be gray, brown or even black. Calcium carbite decomposes with water to form acetylene gas C 2 H 2 - an important chemical product. industry: CaC 2 + 2H 2 O = Ca(OH) 2 + C 2 H 2 Molten metals can combine with other metals to form intermetallic compounds, for example CaSn 3, Ca 2 Sn. 2. Interact with water. Beryllium does not interact with water, because the reaction is prevented by a protective film of oxide on the metal surface. Magnesium reacts with water when heated: Mg + 2H 2 O = Mg(OH) 2 + H 2 Other metals actively interact with water under normal conditions: Ca + 2H 2 O = Ca(OH) 2 + H 2 3. Interaction with acids. All react with hydrochloric and dilute sulfuric acids to release hydrogen: Be + 2HCl = BeCl 2 + H 2 Metals reduce dilute nitric acid mainly to ammonia or ammonium nitrate: 2Ca + 10HNO3 (diluted) = 4Ca(NO3)2 + NH4NO3 + 3H2O In concentrated nitric and sulfuric acids (without heating), beryllium passivates, and other metals react with these acids. 4. Interaction with alkalis. Beryllium reacts with aqueous solutions of alkalis to form a complex salt and release hydrogen: Be + 2NaOH + 2H 2 O = Na 2 + H 2 Magnesium and alkaline earth metals do not react with alkalis. 5. Interaction with metal oxides and salts. Magnesium and alkaline earth metals can reduce many metals from their oxides and salts: TiCl 4 + 2Mg = Ti + 2MgCl 2 V 2 O 5 + 5Ca = 2V + 5CaO Beryllium, magnesium and alkaline earth metals are obtained by electrolysis of melts of their chlorides or by thermal reduction of their compounds: BeF 2 + Mg = Be + MgF 2 MgO + C = Mg + CO 3CaO + 2Al = 2Ca + Al 2 O 3 3BaO + 2Al = 3Ba + Al 2 O 3 Radium is obtained in the form of an alloy with mercury by electrolysis aqueous solution RaCl 2 with mercury cathode. Receipt: 1) Oxidation of metals (except Ba, which forms peroxide) 2) Thermal decomposition of nitrates or carbonates CaCO 3 – t° = CaO + CO 2 2Mg(NO 3) 2 – t° = 2MgO + 4NO 2 + O 2 Determining water hardness is of great practical importance and is widely used in technology, industry and agriculture. Water becomes hard when interacting with calcium and magnesium salts contained in the earth's crust. The dissolution of calcium and magnesium carbonates occurs through the interaction of soil carbon dioxide with these salts. CaCO 3 + CO 2 + H 2 O = Ca(HCO 3) 2 MgCO 3 + CO 2 + H 2 O = Mg(HCO 3) 2 The resulting bicarbonates dissolve in groundwater. Gypsum CaSO 4 slightly directly soluble in water. Distinguish temporary, permanent and general hardness. Temporary or carbonate hardness is caused by the presence of soluble calcium and magnesium bicarbonates in water. This hardness is easily removed by boiling: t 0 Ca(HCO 3) 2 = CaCO 3 + H 2 O + CO 2 Mg(HCO 3) 2 = MgCO 3 + CO 2 + H 2 O Constant water hardness due to the presence of calcium and magnesium salts in it, which do not give sediment when boiled (sulfates and chlorides). The sum of temporary and permanent stiffness is total water hardness. It is determined by the total number of millimoles of equivalents of Ca 2+ and Mg 2+ ions in 1 liter of water (mmol/l) or thousandths of molar masses of equivalents of Ca 2+ and Mg 2+ in 1 liter of water (mg/l). Note: when making calculations related to water hardness, it must be taken into account that E(Ca 2+) = 1/2Ca 2+ and E(Mg 2+) = 1/2 Mg 2+, and Me(Ca 2+) = 1/ 2M Ca 2+ ion = 20 g/mol and Me(Mg 2+) = ½ M Mg 2+ ion = 12 g/mol. Then: 0.02 g is the mass of 0.001 mol or 1 mmol equivalents of Ca 2+. Based on the value of total hardness, water is classified as follows: 1. soft (< 4 ммоль/л), 1. medium hard (4-8 mmol/l), 2. hard (8-12 mmol/l), 3. very hard (>12 mmol/l). Hard water is not suitable for technological processes in a number of sectors and industries. When a steam boiler operates on hard water, its heated surface becomes covered with scale, because... scale conducts heat poorly, and first of all, the operation of the boiler itself becomes uneconomical. Already a layer of scale 1 mm thick increases fuel consumption by approximately 5%. In addition, the walls of the boiler, insulated from water, can heat up to very high temperatures. In this case, the walls oxidize and lose their former strength, which can lead to an explosion of the boiler. Using hard water increases consumption detergents, makes it difficult to wash clothes, wash hair and other operations associated with the consumption of soap. This is due to the insolubility of divalent metal salts and the organic acids that make up soap, which, on the one hand, contaminates the washed objects, and on the other hand, soap is wasted unproductively. You can reduce water hardness different ways: 1) boiling (only for temporary hardness); 2) chemical method (using Ca(OH) 2, Na 2 CO 3, (NaPO 3) 6 or Na 6 P 6 O 18, Na 3 PO 4, etc.) 3) ion exchange method using aluminosilicates: Na 2 H 4 Al 2 Si 2 O 10 + Ca(HCO 3) 2 = CaH 4 Al 2 Si 2 O 10 + 2NaHCO 3 Na 2 H 4 Al 2 Si 2 O 10 + CaSO 4 = CaH 4 Al 2 Si 2 O 10 + Na 2 SO 4 and using ion exchange resins, which are high molecular weight organic substances containing acidic or basic functional groups. Cation exchangers are also used to soften water. For example, when passing hard water through an RNa type cation exchanger, the following ion exchange processes occur: 2RNa + Ca 2+ =R 2 Ca + 2Na + 2RNa + Mg 2+ =R 2 Mg + 2Na + The best way water softening is its distillation. Water hardness is determined using titrimetric methods of quantitative analysis, which is a section analytical chemistry Tasks to control the mastery of the topic 1. For the precipitation of calcium and magnesium bicarbonates from 2 liters of water, 2.12 g of sodium carbonate was consumed. Determine water hardness. 2. Carbonate hardness of water is 40 mg/l equivalents. When 120 liters of this water were boiled, 216.8 g of sediment of a mixture of calcium carbonate and magnesium hydroxycarbonate was released. Determine the mass of each component of the mixture. 3. Hard water contains 50 mg/l calcium bicarbonate and 15 mg/l calcium sulfate. How much (by weight) sodium carbonate will be required to soften 1 m 3 of such water? 4. What mass of sodium phosphate should be added to 500 ml of water. To eliminate its carbonate hardness of 5 mmol equivalents? 5. Calculate what is the hardness of water in 100 liters containing 14.632 g of magnesium bicarbonate? 6. When determining water hardness using the complexometric method, 5 ml of 0.1 N was required to titrate 100 ml of water. Trilon B solution. Calculate the water hardness. 7. 12.95 g of calcium hydroxide was added to 100 liters of hard water. How much has the carbonate hardness of the water decreased? 8. Excess soda was added to hard water containing 1 g of calcium sulfate per liter. What is the hardness of the source water in mg/l equivalents. How many grams of sediment will fall after complete removal of hardness from 1 m 3 of such water? 9. Waste water chemical plant contains in one liter 5g of calcium nitrate and 2g of table salt. What is the hardness of this water in mmol/l. What substance and in what quantity should be added to 10 liters of such water to completely eliminate hardness? 10. Mineral water“Narzan” contains 0.3394 g of calcium and 0.0884 g of magnesium in the form of ions in one liter. What is the total hardness of Narzan in mmol/l? What substance and in what quantity should be added to one cubic meter of “narzan” to completely remove hardness? 11. What is the hardness of water (in mmol/l), if to eliminate it it was necessary to add 15.9 g of anhydrous soda to 100 liters of water? 12. Calculate the hardness of water, knowing that 600 liters of it contain 65.7 g of magnesium bicarbonate and 61.2 g of potassium sulfate. 13. The solubility of gypsum in water is 8 · 10 -3 mol/l. What is the hardness of this (saturated) solution in mg/l? What substance and in what quantity should be added to one cubic meter of such water to completely eliminate its hardness? 14. When 250 ml of water containing calcium bicarbonate was boiled, a precipitate weighing 3.5 mg formed. What is the hardness of water? 15. Determine carbonate hardness if 8 ml of 0.05 N is used to titrate 200 ml of water. HCl solution.
Test papers: OPTION 1 Part 1 A1. The element of the third period of the main subgroup of the III group of PSHE is: A2. Designation of an isotope whose nucleus contains 8 protons and 10 neutrons: A3. An atom of a chemical element whose electron shell contains 17 electrons: A4. An atom has two electronic layers (energy levels): A5. A pair of chemical elements that have 5 electrons at the outer electronic level: A6. A. In a period, the metallic properties of atoms of elements increase with increasing atomic number. B. In a period, the metallic properties of atoms of elements weaken with increasing atomic number. Part 2 IN 1. Particle: Electron distribution: 1) 2e, 8e, 8e, 2e 2) 2e, 8e, 2e 4) 2e, 8e, 3e 5) 2e, 8e, 18e, 4e AT 2. Compounds with ionic bonds are: AT 3. The relative molecular weight of barium chloride BaCl2 is __________. Part 3 C1. Give the characteristics of the element with Z = 11 (Appendix 3, points I (1-5), II (1-4)). Write down the structure diagram of its Na+ ion. Dear eighth grader! For execution test work 40 minutes are allotted. The work consists of 3 parts and includes 10 tasks. Part 1 includes 6 basic level tasks (A1-A6). For each task there are 4 possible answers, of which only one is correct. For completing each task - 1 point. Part 2 consists of 3 advanced level tasks (B1-B3), to which you must give a short answer in the form of a number or a sequence of numbers. For completing each task - 2 points. Part 3 contains 1 of the most complex voluminous tasks C1, which requires a complete answer. For completing the task you can get 3 points. Points received for completed tasks are summed up. You can score a maximum of 15 points. I wish you success! Performance evaluation system: OPTION-2 Part 1 A1. The element of the second period of the main subgroup of the III group of PSHE is: A2. Designation of an isotope whose nucleus contains 26 protons and 30 neutrons: A3. An atom of a chemical element whose nucleus contains 14 protons is: A4. An atom has three electronic layers (energy levels): A5. A pair of chemical elements that have 3 electrons at the outer electronic level: A6. Are the following statements true? A. In the main subgroup, the nonmetallic properties of atoms of elements increase with increasing atomic number. B. In the main subgroup, the nonmetallic properties of atoms of elements weaken with increasing atomic number. Part 2 IN 1. Establish a correspondence between the particle and the distribution of electrons over energy levels: Particle: Electron distribution: 1) 2e, 8e, 7e 2) 2e, 8e, 2e 4) 2e, 8e, 8e 6) 2e, 8e, 8e, 1e AT 2. Compounds with a covalent polar bond are: AT 3. The relative molecular weight of aluminum oxide Al2O3 is _______. Part 3 C1. Give the characteristics of the element with Z = 16 (Appendix 3, points I (1-5), II (1-4)). Write down the structure diagram of its ion S2-. Answers. Part 1 Option 1 Option 2 Part 2 Option 1 Option 2 Part 3 Characteristics plan Option 1 Option 2 I. Position element in periodic system: 1. serial number, name (big, small) 4. group, subgroup 1, main 6, main 5. relative atomic mass II. Structure atom of an element 1. charge of the nucleus of an atom 2. formula atomic composition (number p; n; e -) Na (11p;12n;) 11 e- S (16p; 16n;) 16 e- atomic structure 4. formula electronic configurations 1s2 2s2 2p6 3s23p4 5. number e - at the last level, metal or non-metal 6, non-metal III. Comparison metallic and non-metallic properties with neighbors: 1. by period 2. by group (metal with non-metal do not compare) Structure diagram and she Test No. 2Atomic number Name Atomic mass Electronic configuration g/cm 3 tpl. C tboil. C EO Atomic radius, nm Oxidation state
Beryllium Be 9,01
2s 2 1,86
1,5
0,113
+2
Magnesium Mg 24,3
3s 2 1,74
649,5
1,2
0,16
+2
Calcium Ca 40,08
4s 2 1,54
1,0
0,2
+2
Strontium Sr 87,62
5s 2 2,67
1,0
0,213
+2
Barium Ba 137,34
6s 2 3,61
0,9
0,25
+2
Radium Ra
7s 2 6 700
0,9
–
+2
