Question

state the law of constant proportion give an example

Answer 1

According to law of constant proportion elements are always present in definite proportions by mass .

Answer 2

elements are present in a definite proportion by mass in an compound. this proportion remains the same in that particular compound found anywhere in the world.
for example H2O is a compound in which hydrogen and present in the ration 2:1 by mass so this proportion will remain same everywhere even if the water is a river water or either filtered water...