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What amount of heat must be supplied to 2.0 x 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). |
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Answer» m = 2 × 103 kg-1 = 20g, ∆T = 45°C, M = 28 R = 8.3 J mol-1 K-1, M = 28 Number of moles, n = \(\frac{m}{M} = \frac{20}{5} = \frac{5}{7}\) Since nitrogen is diatomic, ∴ CP = \(\frac{7}{2}\)R = \(\frac{7}{2}\) × 8.3 J mol-1K-1 Now, ∆Q = nCP ∆T \(\frac{5}{2} \times \frac{7}{2}\)× 8.3 × 45J = 933.75J. |
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