Question

${}^{\prime }{N}^{\prime }$ moles of a diatomic gas in a cylinder are at a temperature ${}^{\prime }{T}^{\prime }$. Heat is supplied to the cylinder such that the temperature remains constant but n moles of the diatomic gas gets converted into monatomic gas. What is the change in the total kinetic energy of the gas ?

• A. $\frac{5}{2}nRT$
• B. $\frac{1}{2}nRT$
• C. $0$
• D. $\frac{3}{2}nRT$

Answer 1

The correct option is D $\frac{3}{2}nRT$

$\Rightarrow {KE}_{initial}=\frac{3}{2}nRT$

Final moles$\left(n_2\right)=2n$

Since monoatomic gas conversion is there

$\Rightarrow {KE}_{final}=\frac{3}{2}\times 2nRT$

$\Rightarrow \Delta KE=\frac{3}{2}nRT$