For a certain ideal gas γ = 1.25. Find Cv and Cp…

Molar heat capacities: $C_v = \tfrac{f}{2}R$ and $C_p = C_v + R$ (Mayer), with $\gamma = \dfrac{C_p}{C_v}$. Monatomic: $12.5\ \text{J mol}^{-1}\text{K}^{-1}$, $20.8\ \text{J mol}^{-1}\text{K}^{-1}$, $\gamma = 1.67$. Diatomic: $20.8\ \text{J mol}^{-1}\text{K}^{-1}$, $29.1\ \text{J mol}^{-1}\text{K}^{-1}$, $\gamma = 1.40$. $Q = nC\,\Delta T$, and $\Delta U = nC_v\,\Delta T$ in every process.