If $100$ grams of pure water taken from different sources is decomposed by passing electricity. $11$ grams of hydrogen and $89$ grams of oxygen are obtained. Which chemical law is illustrated by this statement?

Q. 'If 100 grams of pure water taken from different sources is decomposed by passing electricity, 11 grams of hydrogen and 89 grams of oxygen are always obtained'. Which chemical law is illustrated by this statement ?

Q. If $100$ grams of calcium carbonate (whether in the form of marble or chalk ) are decomposed completely, then $56$ grams of calcium oxide and $44$ grams of carbon dioxide are obtained. Which law of chemical combination is illustrated by this statement?

Q. 1.7 gram of silver nitrate dissolved in 100 gram of water is taken. 0.585 gram of sodium chloride dissolved in 100 gram of water is added to it and chemical reaction occurs. 1.435 gm of $AgCl$ and 0.85gm $NaN{O}_3$ are formed. These results illustrate:

Q. Water consists of hydrogen and oxygen, and the approximate ratio, by mass, of hydrogen to oxygen is $2:16$. Approximately how many grams of oxygen are there in $144$ grams of water?

Q.

A liquid compound X of molecular mass 18 u can be obtained from a number of natural sources. All the animals and plants need liquid X for their survival. When an electric current is passed through 200 grams of pure liquid X under suitable conditions, then 178 grams of gas Y and 22 grams of gas Z are produced. Gas Y is produced a the positive electrode whereas gas Z is obtained at the negative electrode. Moreover, gas Y supports combustion whereas gas Z burns itself causing explosions.
(a) Name (i) liquid X (ii) gas Y, and (iii) gas Z.
(b) What is the ratio of the mass of element Z to the mass of element Y in the liquid X ?
(c) Which law of chemical combination is illustrated by this example?
(d) Name two sources of liquid X.
(e) State an important use of Y in our life.