Question

A diatomic gas does 100 J of work when it is expanded isobaric ally. The heat given to the gas during this process is

• A. 700 J
• B. 350 J
• C. 175 J
• D. 1050 J

Answer 1

Answer: (B)

Work done in an isobaric process $W=p(V_2-V_1)$ $W=nR{V}_2-nR{V}_1$ $\Rightarrow$ $T_2-T_1=\frac{W}{nR}$ The heat given in this process $Q=n{C}_p(T_2-T_1)$ $=n{C}_p\left(\frac{W}{nR}\right)=n\left(\frac{7}{2}R\right)\left(\frac{W}{nR}\right)$ $=\frac{7}{2}W=\frac{7}{2}\times 100=350J$