Question

$3$ L of a gas weighs $2$ g at STP. The molecular mass (nearest integer) is:

Answer 1

$3$ L weighs $2$ g.

At, STP 1 mole of gas occpies 22.4L

So, $22.4$ L weighs $\frac{2\times 22.4}{3}=14.93$ g.

So, molecular mass in nearest integer is $15$.