768. What is the action of strong sulphuric acid on each of the following bodies? (a) sodium nitrate, (b) oxalic acid, (c) lead, (d) zinc, (e) potassium chloride, (ƒ) manganese dioxide. Give equations. 769. What is the action of sulphuric acid on organic matter such as sugar? COMPOUNDS OF SELENIUM. 770. How is seleniuretted hydrogen usually obtained? Compare its properties with those of sulphuretted hydrogen. 771. What oxide is formed by burning selenium in oxygen? What is the action of water on it? 772. Give the names and formulæ of the oxychloride and chlorides of selenium which have been obtained. 773. Give a short account of the acids of selenium, and point out their analogies with the acids of sulphur. COMPOUNDS OF TELLURIUM. 774. How is telluretted hydrogen obtained, and what is the weight of a litre of it at N.T. P.? 775. Write the formulæ of all the corresponding compounds of sulphur, selenium, and tellurium which contain (a) hydrogen, (b) chlorine, (c) oxygen, and (d) hydrogen and oxygen. 776. How much oxygen at N.T.P. would be taken up in each case by burning 69 grammes of (a) sulphur, (b) selenium, (d) tellurium, in air? |