Question

4.4 g of an oxide of nitrogen gives 2.24L of nitrogen and 60 g of another oxide of nitrogen gives 22.4 L of nitrogen at S.T.P. The data illustrates

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

Answer 1

Answer: (C)

In first oxide,
Mass of $2\cdot 24L$ of nitrogen at $STP=2\cdot 8g$
$\therefore$ Mass of oxygen $=4\cdot -2\cdot =1\cdot g$
In second oxide
Mass of $22.4L$ of nitrogen at $STP=28g$
$\therefore$ Mass of oxygen $=60-28=32g$
$\therefore$ In second oxide $2\cdot 8g$ of nitrogen combines with $3\cdot 2g$ of oxygen
Keeping the mass of nitrogen same in both oxides, the different masses of oxygen which combines with $2\cdot 8g$ of nitrogen are $1\cdot 6g:3\cdot 2g$ or $1:2$
This is a simple whole number ratio. This illustrates the law of multiple proportions