Question

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

• A. $39.9g$
• B. $22.4g$
• C. $3.56g$
• D. 29 g

Answer 1

Answer: (A)

$39.9g$

Answer 2

(1) : 1 mole occupies a volume of 22.4L at STP

Mass of 1 mole of a gas = Density ×Volume

$= 1.78 \times 22.4 = 39.9g$