Question

$0.24\, g$ of a volatile gas, upon vaporisation, gives $45\, mL$ vapour at NTP. What will be the vapour density of the substance ?
(Density of $ H_2 = 0.089$)

• A. 95.93
• B. 59.93
• C. 95.39
• D. 5.993

Answer 1

Answer: (B)

Weight of gas $=0.24\, g$
Volume of gas $( V )=45\, mL =0.045\, L$
Density of $H_{2}(d)=0.089$
Weight of $45 \, mL$ of $H _{2}= V \times d$
$=0.045 \times 0.089$
$=4.005 \times 10^{-3} \, g$
Therefore, vapour density
$=\frac{\text { Weight of certain volume of substance }}{\text { Weight of same volume of hydrogen }}$
$=\frac{0.24}{4.005 \times 10^{-3}}=59.93$