Question

A vessel contains 1 mole of ${\text{O}}_2$ at $27^{\circ }\text{C}$ and 1 atm pressure. A certain amount of the gas was withdrawn, and the vessel was heated to $327^{\circ }\text{C}$ to maintain the pressure of 1 atm. The amount of gas removed was

• A. 0.2 mole
• B. 0.5 mole
• C. 0.25 mole
• D. 0.1 mole

Answer 1

Answer: (B)

${\text{P}}_1{\text{V}}_1={\text{n}}_1\text{R}{\text{T}}_1$
${\text{P}}_2{\text{V}}_2={\text{n}}_2\text{R}{\text{T}}_2$
${\text{P}}_1={\text{P}}_2,{\text{V}}_1={\text{V}}_2$
$\because {\text{n}}_1{\text{T}}_1={\text{n}}_2{\text{T}}_2$
${\text{n}}_2=\frac{300}{600}=\frac{1}{2}=0.5\text{m}\text{o}\text{l}\text{e}\text{s}$
So half mole of gas was removed.