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)

59.93

Answer 2

(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
$\frac {Weight \, of \, certain \, volume \, of \, substance}{Weight \, of \, same \, volume \, of \, hydrogen}$
$\frac {0.24}{4.005 \times 10 ^{-3}} = 59.93$