A diatomic gas (g = 1.4) does 200 J of work when expanded isobarically. Find the  heat given to the gas in the process.

For a diatomic gas,  $C_V=\frac{5}{2}R,C_p=\frac{7}{2}R$
In an isobaric process, $W=p(V_2-V_1)=nR(T_2-T_1)\Rightarrow T_2-T_1=\frac{W}{nR}$ .
$Q=n{C}_p\Delta T=n{C}_p\frac{W}{nR}=\frac{C_{p}W}{R}=\frac{7}{2}R\frac{W}{R}=\frac{7}{2}\times 200=700\text{\hspace{0.17em}\hspace{0.17em}J}$ .