Question

Take the example of water and explain the law of constant proportion (At.mass

of O is 16u).​

Answer 1

Answer:

This law states that "in a chemical substance, the elements are always present in definite proportions by mass".

For example: 

In water H2O, hydrogen and oxygen are always present in the ratio of 1:8 by mass, whatever the method or source from which water is obtained.

Massof 2 hydrogen atom=2

Mass of one oxygen atom=16

Hence, ratio of hydrogen and oxygen by mass=2:16=1:8