Question

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 at 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

Answer 1

Explanation:

(a) (i) Liquid X is water; (ii) Gas Y is Oxygen; (iii) Gas Z is Hydrogen.

(b) Ratio of the mass of element Z to the mass of element Y in liquid X is 1:8.

(c) In this example, the law of constant proportions is illustrated.

(d) Two sources of liquid X are wells and rivers.

(e) Y is the gas, oxygen. Oxygen is required for respiration.

As per the question,

$X(\text {liquid}) \rightarrow Y(g a s)+Z \text { (gas) }$

$200 g \rightarrow 178 g+22 g$.