1. The hydrogen density of a mixture of methane, propane, oxygen and ozone is 18.4. Burning of 25 ml of this mixture produces 16 ml of a mixture of carbon dioxide with oxygen measured in the same conditions. The hydrogen density of this mixture increased to 19.75.
Calculate the parts by volume of the components of the initial gas mixture.
2. If one adds to the sodium carbonate solution the nitric acid solution at continuous stirring, 11.88 g of salt mixture can be extracted from the solution obtained. In contrary, if one changes the order of mixing the initial solutions, then 11.26 g of salt mixture can be extracted.
Calculate the masses of the substances in the initial solutions. (Please find two ways of finding the solution).
3. The mass part of nitrogen in the mixture
of four gases – oxygen, nitrogen and two other gases with volume ration 4:2:1:3 – is 28%.
Calculate the mass parts of other components of the above mixture provided one of unknown gases is 5 times heavier than the other one. What is their chemical nature?
4. Dissolving 1.856 g of widely spread in nature metal oxide with heating in aqua regia produces 3.9 g of chloride, while dissolving 1.16 g of the same oxide in the concentrated nitric acid at heating produces 3.63.g of nitrate.
Find the chemical nature of the oxide.
5. Calculate at what nitric acid weight percentage in solution the sodium nitrate weight percentage in solution obtained by neutralizing the acid by stereometric quantity of hydrocarbonate will be the same. Please find both partial and general solutions of this task.
6. 4.86 mg of a mixture magnesium carbonate, sodium hydrocarbonate and sodium carbonate react completely with 5.67 g of nitric acid.
Calculate the carbonate masses in the initial mixture taking into account that the sodium hydrocarbonate content in the mixture is 20 mol.%.
7. The increase of the mass of the plate made of metal with oxidation degree of +2 immersed into the 40% lead nitrate solution is 14.5% of the mass of produced solution at the moment, when the lead nitrate concentration decreased to 12 mass.%.
What the metal was immersed into solution?
8. Dissolving 2.88.g of metal oxide in the hydrochloric acid produced 5.08 g of chloride. After treating with the hydrochloric acid the mixture of substances produced at heating of the same quantity of initial oxide in the sealed glass ampoule at t = 570oC, 224 ml of hydrogen (in normal conditions) and 5.79 g of chloride mixture were obtained.
What was the metal oxide?
9. When transferring the water vapors over the heated oxide of certain metal 224 ml of hydrogen (in normal conditions) and 4.80 g of new oxide were obtained. After dissolving the oxide in the hydrochloric acid a chloride (9.75 g) was obtained.
Calculate the mass of the initial oxide taken for reaction.
10. After immersing equal quantities of the same metal into the 1% solutions of sulfuric and nitric acids the increase of the first solution mass was 5.5. g, that of the second solution – 6 g (after complete metal dissolution).
What was the metal taking into account that metal oxidation degree in both cases was +2?
11. Dissolving 6.69 g of a mixture of certain metal oxides, 8.34 g of chloride, 224 ml of hydrogen and 224 ml of chlorine were produced measured in normal conditions.
Calculate the oxide mixture composition taking into account that at dissolving this amount of initial mixture in the nitric acid 9.93 g nitrate was produced. Please find to ways of solving this task.
12. Dissolution of some quantity of lower oxidation degree metal oxide in the concentrated hydrochloric acid produced solution containing 5.5.6 g of chloride that, after saturation with gaseous chlorine, produced 6.98 g of chloride in a form of a yellow fatty liquid soluble in benzene and stable at lower temperatures.
Calculate the quantity of the oxide taken for reaction taking into account that metal oxidation degrees in the above compounds form geometric progression.
13. The binary chemical substance, i.e. the substance the molecules of which consist of atoms of two chemical elements, possesses acidic properties and, reacting with two substances of the same qualitative composition but with different quantitative compositions having basic properties, produces two colorless crystalline compounds that are well soluble in water and have melting temperatures of 160oC and 74.5oC, respectively. The salts produced in reaction with the heavy metal salts form explosive insoluble substance of brisant action.
Name the initial substances and reaction products.
14. Two substances that contain atoms of three chemical elements in normal conditions are liquids with different acidic and basic properties. They react with each other producing a colorless crystalline substance soluble in water having melting temperature of 48oC and containing 66.666 mass% of oxygen.
Determine the nature of the chemical substance.
15. Two colorless solid substances of the same qualitative composition but with different quantitative composition spread in air. One of the above substances dehydrates at t > 213oC, while the second one easily reacts with hot water. Upon aggregating under heating in the sealed glass ampoule at 200–220oC, they produce a colorless crystalline substance with melting temperature about 61oC that is well-soluble in water, reacts slowly with water and contains 2.247 mass%.
Determine the nature of the chemical substance.
16. 4.86 g of mixture of magnesium carbonate, sodium hydrocarbonate and sodium carbonate react completely with 5.67 g of nitric acid.
Calculate the carbonate content in the initial mixture taking into account that the NaHCO3 content in the mixture is 20 mol%.
17.5.22 g of mixture of lithium carbonate, calcium hydroxide and hydroxide of metal with the oxidation degree of +1 react completely with 5.04 g of nitric acid.
Calculate the mass part of the hydroxide of unknown metal if the molar part of this component of the mixture is 40%.
18. An iron plate was immersed into the copper sulphate solution. After certain time the mass of the plate increased by 0.1% of the mass of resultant solution.
Calculate the copper sulphate concentration in the initial solution if its concentration in the resultant solution is 8 mass%.
19. Upon cooling the lead nitrate solution saturated at the T1oC temperature,150 g of salt crystallized.
Calculate the mass of the initial solution and the lead nitrate solubility at T1oC if the molal concentration of the solution decreased from 3.776 to 1.511.
20. The increase of the mass of the plate made of the metal showing the +2 oxidation degree immersed into the 40% lead nitrate solution at the moment when the lead nitrate concentration decreased to 12% is 14.5% of the mass of resultant solution.
Name this metal.
21. Potassium hydroxide, except for the known reactants, in powdered state, frequently at heating only, reacts with metallic potassium, iron, carbon, ozone, carbon oxide (II) and nitrogen oxide (II). State the conditions of occurring the relevant chemical reactions.
22. Carbon oxide (II) being transported over the melted metallic potassium with low yields produces the C6O6K6 substance. The latter being treated by the water solutions of mineral acids having no oxidizing properties produces the C6H6O6 substance and immediately deoxidizing silver from the water solutions of its salts producing the C6O6 substance.
Draw the graphical formulae of the substances produced.
23. Calculate the volume of the0.3 m HCl solution required to react with 6 g of mixture of magnesium oxide, calcium hydrocarbonate, cesium hydroxide, the potassium hydrocarbonate and cesium hydroxide contents of which are 37.5 mass% and 20 mol%, respectively.
24. Upon immersing the same quantities of the same metal into 1% solutions of sulfuric and nitric acids the increase of the mass of the first solution is6.75 g , while that of the second solution is 7 g . Name this metal taking into account the fact that the oxidation degree of the metal for compounds produced is +2.
Contact phone (mobile): +38 066 9523460.
Calculate the parts by volume of the components of the initial gas mixture.
2. If one adds to the sodium carbonate solution the nitric acid solution at continuous stirring, 11.88 g of salt mixture can be extracted from the solution obtained. In contrary, if one changes the order of mixing the initial solutions, then 11.26 g of salt mixture can be extracted.
Calculate the masses of the substances in the initial solutions. (Please find two ways of finding the solution).
3. The mass part of nitrogen in the mixture
of four gases – oxygen, nitrogen and two other gases with volume ration 4:2:1:3 – is 28%.
Calculate the mass parts of other components of the above mixture provided one of unknown gases is 5 times heavier than the other one. What is their chemical nature?
4. Dissolving 1.856 g of widely spread in nature metal oxide with heating in aqua regia produces 3.9 g of chloride, while dissolving 1.16 g of the same oxide in the concentrated nitric acid at heating produces 3.63.g of nitrate.
Find the chemical nature of the oxide.
5. Calculate at what nitric acid weight percentage in solution the sodium nitrate weight percentage in solution obtained by neutralizing the acid by stereometric quantity of hydrocarbonate will be the same. Please find both partial and general solutions of this task.
6. 4.86 mg of a mixture magnesium carbonate, sodium hydrocarbonate and sodium carbonate react completely with 5.67 g of nitric acid.
Calculate the carbonate masses in the initial mixture taking into account that the sodium hydrocarbonate content in the mixture is 20 mol.%.
7. The increase of the mass of the plate made of metal with oxidation degree of +2 immersed into the 40% lead nitrate solution is 14.5% of the mass of produced solution at the moment, when the lead nitrate concentration decreased to 12 mass.%.
What the metal was immersed into solution?
8. Dissolving 2.88.g of metal oxide in the hydrochloric acid produced 5.08 g of chloride. After treating with the hydrochloric acid the mixture of substances produced at heating of the same quantity of initial oxide in the sealed glass ampoule at t = 570oC, 224 ml of hydrogen (in normal conditions) and 5.79 g of chloride mixture were obtained.
What was the metal oxide?
9. When transferring the water vapors over the heated oxide of certain metal 224 ml of hydrogen (in normal conditions) and 4.80 g of new oxide were obtained. After dissolving the oxide in the hydrochloric acid a chloride (9.75 g) was obtained.
Calculate the mass of the initial oxide taken for reaction.
10. After immersing equal quantities of the same metal into the 1% solutions of sulfuric and nitric acids the increase of the first solution mass was 5.5. g, that of the second solution – 6 g (after complete metal dissolution).
What was the metal taking into account that metal oxidation degree in both cases was +2?
11. Dissolving 6.69 g of a mixture of certain metal oxides, 8.34 g of chloride, 224 ml of hydrogen and 224 ml of chlorine were produced measured in normal conditions.
Calculate the oxide mixture composition taking into account that at dissolving this amount of initial mixture in the nitric acid 9.93 g nitrate was produced. Please find to ways of solving this task.
12. Dissolution of some quantity of lower oxidation degree metal oxide in the concentrated hydrochloric acid produced solution containing 5.5.6 g of chloride that, after saturation with gaseous chlorine, produced 6.98 g of chloride in a form of a yellow fatty liquid soluble in benzene and stable at lower temperatures.
Calculate the quantity of the oxide taken for reaction taking into account that metal oxidation degrees in the above compounds form geometric progression.
13. The binary chemical substance, i.e. the substance the molecules of which consist of atoms of two chemical elements, possesses acidic properties and, reacting with two substances of the same qualitative composition but with different quantitative compositions having basic properties, produces two colorless crystalline compounds that are well soluble in water and have melting temperatures of 160oC and 74.5oC, respectively. The salts produced in reaction with the heavy metal salts form explosive insoluble substance of brisant action.
Name the initial substances and reaction products.
14. Two substances that contain atoms of three chemical elements in normal conditions are liquids with different acidic and basic properties. They react with each other producing a colorless crystalline substance soluble in water having melting temperature of 48oC and containing 66.666 mass% of oxygen.
Determine the nature of the chemical substance.
15. Two colorless solid substances of the same qualitative composition but with different quantitative composition spread in air. One of the above substances dehydrates at t > 213oC, while the second one easily reacts with hot water. Upon aggregating under heating in the sealed glass ampoule at 200–220oC, they produce a colorless crystalline substance with melting temperature about 61oC that is well-soluble in water, reacts slowly with water and contains 2.247 mass%.
Determine the nature of the chemical substance.
16. 4.
Calculate the carbonate content in the initial mixture taking into account that the NaHCO3 content in the mixture is 20 mol%.
17.
Calculate the mass part of the hydroxide of unknown metal if the molar part of this component of the mixture is 40%.
18. An iron plate was immersed into the copper sulphate solution. After certain time the mass of the plate increased by 0.1% of the mass of resultant solution.
Calculate the copper sulphate concentration in the initial solution if its concentration in the resultant solution is 8 mass%.
19. Upon cooling the lead nitrate solution saturated at the T1oC temperature,
Calculate the mass of the initial solution and the lead nitrate solubility at T1oC if the molal concentration of the solution decreased from 3.776 to 1.511.
20. The increase of the mass of the plate made of the metal showing the +2 oxidation degree immersed into the 40% lead nitrate solution at the moment when the lead nitrate concentration decreased to 12% is 14.5% of the mass of resultant solution.
Name this metal.
21. Potassium hydroxide, except for the known reactants, in powdered state, frequently at heating only, reacts with metallic potassium, iron, carbon, ozone, carbon oxide (II) and nitrogen oxide (II). State the conditions of occurring the relevant chemical reactions.
22. Carbon oxide (II) being transported over the melted metallic potassium with low yields produces the C6O6K6 substance. The latter being treated by the water solutions of mineral acids having no oxidizing properties produces the C6H6O6 substance and immediately deoxidizing silver from the water solutions of its salts producing the C6O6 substance.
Draw the graphical formulae of the substances produced.
23. Calculate the volume of the
24. Upon immersing the same quantities of the same metal into 1% solutions of sulfuric and nitric acids the increase of the mass of the first solution is
Contact phone (mobile): +38 066 9523460.
Комментариев нет:
Отправить комментарий