Question

An open vessel at ${27}^{\circ }C$ is heated until ($\frac{2}{5}$)th of the air in it has been expelled. Assuming that the volume of the vessel remains constant. Which of the following option is correct?

• A. Final temperature is 500 K
• B. Final volume is 2 times the initial volume
• C. Final pressure is 1 atm
• D. None of the above

Answer 1

The correct option is A Final temperature is 500 K

$T_1=27°C=27+273=300K$

Let $n_1$ be n.

$n_2=n-\frac{2n}{5}=\frac{3n}{5}$

$T_2$=?

We know that, $n_1{T}_1=n_2{T}_2$

$⟹n\times 300=\frac{3n}{5}\times T_2⟹T_2=500K=500-273=227°C$