Question

If Q amount of heat is given to a diatomic ideal gas in a process, the gas performs a work of $\frac{2Q}{3}$ on its surrounding. Find the molar heat capacity for the process

• A. 2.5 R
• B. 4.5 R
• C. 6 R
• D. 7.5 R

Answer 1

The correct option is D 7.5 R

$\Delta Q=W+\Delta U\Rightarrow nC\Delta T=\frac{2Q}{3}+\frac{Q}{3}\Rightarrow nC\Delta T=3\frac{Q}{3}\Rightarrow nC\Delta T=3\times \frac{f}{2}nR\Delta T\Rightarrow C=7.5R$