Question

The density of a gas is $1.78g{L}^{-1}$ at $STP$ . The weight of one mole of a gas is

• A. $39.9g$
• B. $24.4g$
• C. $3.56g$
• D. $29g$

Answer 1

Answer: (A)

$1$ mole occupies a volume of $22.4L$ at $STP$
Mass of $1$ mole of gas = Density $\times$ Volume
$=1.78\times 22.4=39.9g$