QUESTIONS ON CHAPTER XXII. 141 



110. What constitutes a true chemical compound ? Give examples. 



111. What important Law of Chemistry enables you to predict the exact 

 amount of oxygen you should get from, say, a gram of chlorate of potash, 

 or the amount of carbon dioxide from a gram of chalk ? 



Give an account of any experiments and class results which led to this 

 generalisation. 



112. It is stated that when a chemical change takes place, matter is 

 neither created nor destroyed. Explain this statement. How can you 

 reconcile it with the results obtained when copper and chalk are strongly 

 heated in open crucibles ? 



113. What do you understand by the Indestructibility of Matter ? How 

 do you reconcile your views with the effects observed when (a) magnesium, 

 (6) chalk, is strongly heated ? 



