Question

The vapour density of a gas is $8$. Its $5.6L$ at NTP weighs:

• A. 8 g
• B. 32 g
• C. 16 g
• D. 4 g

Answer 1

The correct option is D 4 g

$\text{given Vapour density}=8$

$\begin{array}{cc}\text{molecular weight}& =2\times V\cdot D\\ & =2\times 8=16\end{array}$

$\text{its}5.6L\text{at NTP weight}$

$\mathrm{Equivalent\; weight}=\frac{Mwt}{\text{valency factor}}=\frac{16}{22.4}\times 5.6$

$\begin{array}{c}\text{Equivalent weight}=\frac{16\times 5.6}{22.44}\\ \text{Equivalent weight}=4g\end{array}$