Question

1 mole of an ideal gas is maintained at 4.1 atm and at a certain temperature absorbs 3710 J heat and expands to 2 litres. Calculate the entropy change in expansion process.

Answer 1

Given, 

n = 1 mole

P = 4.1 atm

V = 2 Lit

T = ?

q = 3710 J

Answer 2

Pressure of an ideal gas P_i = 4.1 atm. 

Expansion in volume = ∆V = 2 litres 

Heat absorbed = q = 3710 J 

Entropy change = ∆S = ? 

For an ideal gas PV = RT for one mole. 

T = PV/R = 4.1x₂/0.830 = 100°C 

T = 100 + 273 = 373 K.

∆S = q/T_(K) = 3710/373

Entropy change = 9.946 JK^-1