Question

An ideal gas expands from 100 cm3 to 200 cm3 at a constant pressure of 2.0 x 105 Pa when 50 J of heat is supplied to it. Calculate (a) the change in internal energy of the gas, (b) the number of ***** in the gas if the initial temperature is 300 K, (c) the molar heat capacity Cp at constant pressure and (d) the molar heat capacity Cv at constant volume.

Answer 1

V1 = 100 cm3, V2 = 200 cm3 P = 2 × 105 Pa, ΔQ = 50J
(a) ΔQ = du + dw => 50 = du + 20× 105(200 – 100 × 10–6) => 50 = du + 20 => du = 30 J