A 1.9862-g sample of benzoic acid burns in an excess of oxygen, in a bomb calorimeter. The temperature of the?calorimeter rises from...?
2014-12-17 7:12 am
A 1.9862-g sample of benzoic acid burns in an excess of oxygen, in a bomb calorimeter. The temperature of the?calorimeter rises from 24.94 C to 28.77 C. The calorimeter contains 2000.0 g of H2O, and the heat capacity of the calorimeter (including the bomb, thermometer, and all mechanical parts) has the value C(cal) = 5.35 kJ/C. Use the given information to find the molar heat of combustion of benzoic acid (M(benzoic acid) = 122.1 g/mol).
回答 (1)
2014-12-18 4:38 am
(4.184 J/g·°C) x (2000.0 g) = 8368 J/°C = 8.368 kJ/°C for the water only
(8.368 kJ/°C) + (5.35 kJ/°C) = 13.718 kJ/°C for the entire apparatus, water included
(13.718 kJ/°C) x (28.77 - 24.94) °C = 52.5399 kJ
(52.5399 kJ) / ((1.9862 g C6H5COOH) / (122.1213 g C6H5COOH/mol)) = 3230 kJ/mol
(8.368 kJ/°C) + (5.35 kJ/°C) = 13.718 kJ/°C for the entire apparatus, water included
(13.718 kJ/°C) x (28.77 - 24.94) °C = 52.5399 kJ
(52.5399 kJ) / ((1.9862 g C6H5COOH) / (122.1213 g C6H5COOH/mol)) = 3230 kJ/mol
收錄日期: 2021-04-21 01:01:26
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