Question

A monatomic ideal gas undergoes a process in which the ratio of P to V at any instant is constant and equals to 1. What is the molar heat capacity of the gas? 

(A) 4R/2 

(B) 3R/2

(C) 5R/2 

(D) 0

Answer 1

Correct option (A) 4R/2

Explanation:

Given, P/V = 1 ⇒ p = V

Also from first law: dq = Cv dT + pdV

For one mole of an ideal gas: pV = RT

⇒ pdV + Vdp = RdT

From (i) pdV = Vdp

Substituting in Eq. (ii) gives

2pdV = RdT