Assuming ideal gas behavior the change in enthalpy of the nitrogen gas is given by:

H = nCpT

The molar heat capacity at constant pressure for an diatomic ideal gas like nitrogen is

Cv = (7/2)R

Hence,

Q =(5/2)nRT

A

Process A is a constant volume process. The heat transferred in such a process equals the change in internal energy of the gas.

Q = U

Assuming ideal gas behavior the change in internal energy of the nitrogen gas is given by:

U = nCvT

The molar heat capacity at constant volume for an diatomic ideal gas like nitrogen is

Cv = (5/2)R

Hence,

Q =(5/2)nRT

From ideal gas law

nRT = pV

follows for an constant volume process:

nRT = (pV) = Vp

Hence,

Q =(5/2)Vp = (5/2)V(p_f p_i)

= (5/2) 2000cm (1atm 3atm)

= (5/2) 2000m10m (- 2 1.0132510 Pa)

= -1013.25 J

B

Process B is a constant pressure process. The heat transferred in such a process equals the change in enthalpy of the gas.

Q = H

Assuming ideal gas behavior the change in enthalpy of the nitrogen gas is given by:

H = nCpT

The molar heat capacity at constant pressure for an diatomic ideal gas like nitrogen is

Cv = (7/2)R

Hence,

Q =(5/2)nRT

From ideal gas law

nRT = pV

follows for an constant pressure process:

nRT = (pV) = pV

Hence,

Q =(7/2)pV = (5/2)p(V_f V_i)

= (7/2) 2atm (3000cm 1000cm)

= (7/2) 21.0132510 Pa 2000m10m

= 1418.55 J

This post is last updated on hrtanswers.com at Date : 1st of September – 2022