The value of CP – CV = 1.00 R for a gas in state A and Cp – Cv = 1.06R in another state….

Q: The value of CP – CV = 1.00 R for a gas in state A and CP – CV = 1.06R in another state. If PA and PB denote the pressure and TA and TB denote the temperatures in the two states, then

(a) PA = PB, TA > TB

(b) PA > PB, TA = TB

(c) PA < PB, TA > TB

(d) PA = PB, TA < TB

Ans: (c)

Sol: For Ideal gas
CP – CV = R (for State A)

But for state B ,

CP – CV = 1.06R

Hence it does not behave like an ideal gas .

As we know that for ideal gas pressure should be low & temperature should be high .

PA < PB & TA > TB