Question

4 g of a gas occupies 22.4 L at N.T.P. The specific heat capacity of the gas at constant volume is 5.0 J K^-1 mol^-1. If the speed of sound in this gas at NTP is 952 ms^-1, then the heat capacity at constant pressure is:
(Take gas constant R = 8.3 JK^-1 mol^-1)

(a) 8.0 J K^-1 mol^-1

(b) 7.5 J K^-1 mol^-1

(c) 7.0 J K^-1 mol^-1

(d) 8.5 J K^-1 mol^-1

Answer 1

Correct option is : (a) 8.0 J K^-1 mol^-1

(a) Given, m = 4g, V = 22.4 L, C_V = 5 JK^-1 mol^-1

v_sound = 952 m/s, C_P = ?

= \(\frac{20}{22.4}\)x (952)² x 10⁵

= 809.200 x 10^-5

= 8.09 J/mol K