Question

A sample of pure water, irrespective of source, contains 88.89% oxygen and 11.11% hydrogen
by mass. The data supports the:

• A. law of conservation of mass
• B. law of constant composition
• C. law of multiple proportion
• D. law of reciprocal proportion

Answer 1

The correct option is B law of constant composition

According to the law of constant composition in a given compound, the elements always combine in the same proportion as each other.

Water($H_{2}O$) molecule consists of two hydrogen atoms of relative mass 1 and one oxygen atom of relative mass 16.

Therefore, the ratio in which 2 atoms of hydrogen and one atom of oxygen are combined is $1:8$ and will always be the same irrespective of the source of water.

Therefore, the correct option is $B$