Question

In an experiment, $2.4g$ of iron oxide on reduction with hydrogen gave $1.68g$ of iron. In another experiment, $2.69g$ of iron oxide gave $1.88g$ of iron on reduction. Which law is illustrated from the above data?

• A. Law of constant proportions
• B. Law of multiple proportions
• C. Law of reciprocal proportions
• D. Law of conservation of mass

Answer 1

The correct option is A Law of constant proportions

In the first experiment,

$2.4g$ of iron oxide gave $1.68g$ of iron.
Mass of iron oxide $=2.4g$

Mass of iron $=1.68g$

$\therefore$ Mass of oxygen $=2.4-1.68=0.72$

The ratio of masses of iron and oxygen $=\frac{1.68}{0.72}=7:3$

In the second experiment,

Mass of iron oxide $=2.69g$

Mass of iron $=1.88g$

Mass of oxygen $=2.69-1.88=0.81$

The ratio of masses of iron and oxygen $=\frac{1.88}{0.81}=7:3$

The same ratio confirms that these experiments clarify Law of constant proportion.

Hence, option $A$ is correct.