Question

What amount of heat must be supplied to 2.0 × 10^–2 kg of nitrogen (at room temperature) to raise its temperature by 45°C at constant pressure? (Molecular mass of N₂ = 28; R = 8.3 J mol^–1 K^–1.)

Answer 1

Dear Student,

Mass of nitrogen, m = 2.0 × 10–2 kg = 20 g
Rise in temperature, ΔT= 45°C
Molecular mass of N2, M= 28
Universal gas constant, R= 8.3 J mol–1 K–1
Number of moles, n = m/M
= (2 × 10-2 × 103) / 28
= 0.714
Molar specific heat at constant pressure for nitrogen, Cp = (7/2)R
= (7/2) × 8.3
= 29.05 J mol-1 K-1
The total amount of heat to be supplied is given by the relation:
ΔQ = nCP ΔT
= 0.714 × 29.05 × 45
= 933.38 J
Therefore, the amount of heat to be supplied is 933.38 J.

Regards