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.)
Mass of nitrogen, m=2.0×10−2kg=20g Rise in temperature, ΔT=45oC Molecular mass of N2,M=28 Universal gas constant, R=8.3J/molK 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 =29.05Jmol−1K−1 The total amount of heat to be supplied is given by the relation: Q=nCPΔT =0.714×29.05×45 =933.38J Therefore, the amount of heat to be supplied is 933.38 J.
