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 A certain amount of the gas was withdrawn, and the vessel was heated to $327^\circ \text{C}$ to maintain the pressure of 1 atm.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.