• # question_answer An open vessel at $27{}^\circ C$ is heated until two fifth of the air (assumed as an ideal gas) in it has escaped from the vessel. Assuming that the volume of the vessel remains constant, the temperature at which the vessel has been heated is: A) $500{}^\circ C$ B) 500 K C) $750{}^\circ C$ D) 750 K

 ${{n}_{1}}{{T}_{1}}={{n}_{2}}{{T}_{2}}$ $n\times 300=\left( n-\frac{2n}{5} \right){{T}_{2}}$ $300=\frac{3}{5}{{T}_{2}}$$\Rightarrow$       ${{T}_{2}}=500\,K.$