Question

Which one of the following combinations illustrate the law of reciprocal proportions?

• A. $N_2{O}_3,N_2{O}_4,N_2{O}_5$
• B. $NaCl,NaBr,NaI$
• C. $C{S}_2,C{O}_2,S{O}_2$
• D. $P{H}_3,P_2{O}_3,P_2{O}_5$

Answer 1

Answer: (C)

Explanation:
In $C{S}_2$ the ratio of the masses of $C:S=12:64$
In $C{O}_2$ the ratio of the masses of $C:O=12:32$
So, the ratio of the masses of $S:O$ combining with fixed mass of $C=64:32=2:1$
In $S{O}_2$, the ratio of the masses of $S:O=1:1$
So,
$\frac{2}{1}=2\times \left(\frac{1}{1}\right)$
Hence, this set follows law of reciprocal proportions.

Hence, option (C) is correct.