Question

P-V diagram of a diatomic gas is a straight line passing through origin. The molar heat capacity of the gas in the process will be –

• A. 4R
• B. 2.5 R
• C. 3 R
• D. $\frac{4R}{3}$

Answer 1

Answer: (A)

4R

Answer 2

P = KV

PV = nRT

KV² = nRT

2KVdV = nRdT

W = $\int_{}^{}{KVdV}$ = $\frac { \mathrm { nR } } { 2 }$ $\int_{}^{}{dT}$= $\frac{nR}{2}$DT

from first law of thermodynamics

Q = W + DU

nCDT = $\frac{nR}{2}$DT + nC_VDT

C = $\frac{R}{2}$+C_V = $\frac{R}{2}$+$\frac{7R}{2}$ = 4R