10. (a) Does dry sulphur dioxide react with litmus paper? (b) How can it be shown that a solution of sulphur dioxide in water acts like an acid?
11. (a) Calculate the percentage composition of sulphurous anhydride and sulphuric anhydride. (b) Show how these two substances are in harmony with the law of multiple proportion.
12. How many pounds of sulphur would be necessary in the preparation of 100 lb. of 98% sulphuric acid?
13. What weight of sulphur dioxide is necessary in the preparation of 1 kg. of sodium sulphite?
14. What weight of copper sulphate crystals can be obtained by dissolving 1 kg. of copper in sulphuric acid and crystallizing the product from water?
15. Write the names and formulas of the oxides and oxygen acids of selenium and tellurium.
16. In the commercial preparation of carbon disulphide, what is the function of the electric current?
17. If the Gay-Lussac tower were omitted from the sulphuric acid factory, what effect would this have on the cost of production of sulphuric acid?