Question

Which of the following combinations illustrate law of reciprocal ?

(a) N₂O₃, N₂O₄, N₂O₅

(b) PH₃, P₂O₅, P₂S₅

(c) CS₂, CO₂, SO₂

(d) NaCl, NaBr, Nal

Answer 1

Correct option is (c) CS₂, CO₂, SO₂

In CS₂ the ratio of the masses of C:S = 12:64

In CO₂ 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 SO₂, the ratio of the masses of S:O = 1:1

So,

\(\frac21\) = 2 × (\(\frac 11\))

Hence, this set follows law of reciprocal proportions.