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.
- Name (i) liquid X (ii) gas Y, and (iii) gas Z.
- What is the ratio of the mass of element Z to the mass of element Y in the liquid X ?
- Which law of chemical combination is illustrated by this example ?
- Name two sources of liquid X.
- State an important use of Y in our life.
(i) Liquid X is water (H2O).
(ii) Gas Y is oxygen.
(iii) Gas Z is hydrogen.
The ratio of element Z to element Y by mass = 22:178
Therefore, ratio of Z : Y by mass = 1:8
The law of constant proportions is illustrated by this example.
Liquid X has already been stated as water. Oceans and rivers are the important sources of water on earth.
Y, oxygen, is essential for our survival. We breathe in oxygen during respiration.