Question

1.The heat needed to raise the temperature by 10 C of the 10 moles an ideal gas is 2100J.

Find:

a)the change in volume.

b)heat capacities pressure and at constant volume, if during that process the pressure is constant and is equal 1.0*10*5 Pa?

Answer 1

1. (a) Ideal gas equation is given by

PV = nRT

At constant pressure P (P = 1.0 x 10⁵ Pa)

:. PdV = nRT

n RdT :.0V = D = 10 X 8.314 x 10 m 1.0 x 105 = 8314 cm

(b) Heat capacity of ideal gas at constant pressure is C_p. Here in this problem, the heat required to raise temperature of $\Delta T$ for n mole of monatomic ideal gas will be

dQ = nCAT

:: 2100 = 10 x C x 10

..C, = 21 J. mol-1. K-1

The ratio of specific heat at constant pressure and constant volume is $\gamma$ which is equal to 1.66 for an ideal monatomic gas and 1.4 for a diatomic gas. Then for monoatomic gas the specific heat at constant volume will be

= 12.65.J. mol-1. K-1