Question

7.5 litre of the particular gas at S.T.P. as weight 16 gram. What is the V.D. of gas?

• A. 23.89
• B. 24
• C. 2.398
• D. 22

Answer 1

The correct option is A 23.89

Given,

volume - $7.5l$

weight - $16g$

Molecular mass = vapour density$\times 2$

At STP,

one mole of gas = $22.4l$

so, number of moles in $7.5l$ = $\frac{1}{22.4}\times 7.5=0.3348$ mole

$0.334$ mole of gas has weight - $16g$

one mole - $\frac{16}{0.3348}=47.78g$

Here, we got molecular mass - $47.78g$

Vapour density = $\frac{47.78}{2}=23.89$

Hence, option A is the correct answer.