Question

An equi-molar mixture of a monoatomic and a diatomic gas is subjected to a continuous and reversible process such that for an infinite small part of the process, dQ = – $\frac { 1 } { 3 }$dU where dQ is the heat input to the gas. The molar heat capacity of the two during the process is –

• A. –$\frac { 1 } { 3 }$R
• B. $\frac { 2 } { 3 }$ R
• C. –$\frac { 2 } { 3 }$R
• D.

Answer 1

Answer: (C)

–$\frac { 2 } { 3 }$R

Answer 2

dQ = – $\frac { 1 } { 3 }$ dU

nCdT = – $\frac { 1 } { 3 }$ nC_vDt