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.
Answers
Oxygen is necessary for Breathing
Explanation:
(a) (i)X is Water
(ii) Y is Oxygen
(iii) Z is Hydrogen
(b) Ratio of 1:8
(c) Law of Constant Proportions
(d) Wells and Rivers
(e) Y gas is necessary for Breathing, as its Oxygen
* Kindly refer the figure as attachment
The answers to the following questions are:
(a) (i) The liquid X is Water (H2O).
(ii) The gas Y is Oxygen (O2).
(iii) The gas Z is Hydrogen (H2).
(b) The ratio of the mass of element Z to the ratio of the mass of Y = 22/178
⇒ Z:Y = 1:8
(c) The Law of Definite Proportions is illustrated by this example.
(d) The sources of liquid X, i.e., water are Rain, Rivers, Lakes and Underground Water.
(e) The gas Y, i.e., oxygen gas has the most important function in our life, Breathing.
- We use oxygen by breathing for the respiration process to produce energy for our living.