Question

The molar volume of $CO_2$ is maximum at:

• A. $NTP$
• B. $0^{\circ} C$ and $2.0$ atm
• C. $127^{\circ} C$ and $1$ atm
• D. $273^{\circ} C$ and $2$ atm

Answer 1

Answer: (C)

$127^{\circ} C$ and $1$ atm

Answer 2

From ideal gas equation, $pV = nRT$ $\Rightarrow V=\frac{n R T}{p}$ For $n =1 mole$ $V=\frac{R T}{p}$ $\Rightarrow V \propto T$ $\therefore$ The molar volume of $CO _{2}$ at a)NTP $V=\frac{0.0821 \times 273}{1}=22.4\, L$ b) $0^{\circ} C$ and $2.0\, atm$ $V=\frac{0.0821 \times 273}{2.0}=11.2\, L$ c) $127^{\circ} C$ and $1\, atm$ $V=\frac{0.0821 \times 400}{1}=32.84\, L$ d) $273^{\circ} C$ and $2\, atm$ $V=\frac{0.0821 \times 546}{2}=22.4\, L$ Therefore the molar volume of $CO _{2}$ is maximum at $127^{\circ} C$ and $1\, atm$.