Question

The molar heat capacity at constant pressure Cp/n of a gas varies with the temperature according to the equation = + − 2 where a, b and c are constant. How much heat is transferred during an isobaric process in which n moles of gas experience a temperature rise from Ti to Tf​

Answer 1

Answer:

Correct option is

B

V=e

(

2R

3aT

2

)

Using 1st law of thermodynamics for small time, dQ=dU+dW

∴ nCdT=nC

V

dT+PdV

⟹ C=C

V

+

n

P

dT

dV

Comparing with C=C

V

+3aT

2

we get

n

P

dT

dV

=3aT

2

∴

V

RT

dT

dV

=3aT

2

(∵PV=nRT)

OR ∫

V

dV

=

R

3a

∫TdT

⟹ lnV=

R

3a

2

T

2

⟹ V=e

(

2R

3aT

2

)

Answer 2

Explanation:

b, and c are constants. How much heat is transferred during an isobaric process in which n moles of gas experience a temperature rise from Ti to Tf?