Question

An open vessel at 27${}^o$C is heated until $\frac{3}{5}$th of the air in it has been expelled. The temperature to which the vessel must be heated to achieve this (in ${}^o$C) is:

• A. 750
• B. 300
• C. 600
• D. 477

Answer 1

The correct option is A 750

Since pressure and volume are constant, so

$n_1{T}_1=n_2{T}_2$

If, $n_1=n$ and $T_1=300K$

Then, $n_2=\frac{2n}{5}$

Now, substituting in the above equation

$T_2=\frac{T_1\times n_1}{n_2}=\frac{300\times n}{\frac{2n}{5}}$

$T_2=750K$

Option A is correct.