Question

If 1 $g$ of each of the following gases are taken at $STP$, which of the gases will occupy greatest volume?

• A. $H_{2}O$
• B. $CO$
• C. $C{H}_4$
• D. $NO$

Answer 1

Answer: (C)

$C{H}_4$

If 1 $g$ of each of the following gases are taken at $STP$, $C{H}_4$ will occupy greatest volume.
$PV=nRT$
The volume of the gas is directly proportional to the number of moles which in turn is inversely proportional to the molar mass.
Thus, the gas having minimum molar mass will occupy greatest volume.
The molar masses of (A) $H_{2}O$, (B) $CO$, (C) $C{H}_4$ and (D) $NO$ are 18 $g/mol$, 28 $g/mol$, 16 $g/mol$ and 30 $g/mol$ respectively.
The molar masses of methane is minimum. Hence, it will occupy maximum volume at $STP$.