State the law of Multiple Proportions. Explain with two examples.
The Law of Multiple Proportions states: “When two elements combine to form two or more than two chemical compounds than the weights of one of elements which combine with a fixed weight of the other, bear a simple ratio to one another. Examples: 1. Compound of Carbon and Oxygen: C and O combine to form two compounds CO and CO2. In CO2 12 parts of wt. of C combined with 16 parts by wt. O. In CO2 12 parts of wt. of C combined with 32 parts by wt. of O. If the weight of C is fixed at 12 parts by wt. then the ratio in the weights of oxygen which combine with the fixed wt. of C (= 12) is 16: 32 or 1: 2. Thus the weight of oxygen bears a simple ratio of 1: 2 to each other. 2. Compounds of Sulphate (S) and Oxygen (O): S forms two oxides with O, viz., SO2 and SO3 In SO2, 32 parts of wt. of S combine with 32 parts by wt. of O. In SO3, 32 parts of wt. of S combine with 48 parts by wt. of O. If the wt. of S is fixed at 32 parts, then’ the ratio in the weights of oxygen which combine with the fixed wt. of S is 32: 48 or 2: 3. Thus the weights of oxygen bear a simple ratio of 2: 3 to each other.
