A 35.6 g sample of ethanol (c2h5oh) is burned in a bomb calorimeter, according to the following reaction. if the temperature rose from 35.0 to 76.0Â°c and the heat capacity of the calorimeter is 23.3 kj/Â°c, what is the value of Î'hÂ°rxn? the molar mass of ethanol is 46.07 g/mol.

Question

Chemistry

Davion Schmidt

28 November, 09:24

A 35.6 g sample of ethanol (c2h5oh) is burned in a bomb calorimeter, according to the following reaction. if the temperature rose from 35.0 to 76.0Â°c and the heat capacity of the calorimeter is 23.3 kj/Â°c, what is the value of Î'hÂ°rxn? the molar mass of ethanol is 46.07 g/mol.

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Spirit · Answer 1

Answer is: molar heat of reaction of combustion of ethanol is 1237.435 kJ/mol.

m (C₂H₅OH) = 35.6 g.

n (C₂H₅OH) = m (C₂H₅OH) : M (C₂H₅OH).

n (C₂H₅OH) = 35.6 g : 46.07 g/mol.

n (C₂H₅OH) = 0.772 mol.

ΔT = 76.0°C - 35.0°C = 41°C.

Q = ΔT · C.

Q = 41°C · 23.3 kJ/°C.

Q = 955.3 kJ.

ΔH = Q / n (C₂H₅OH).

ΔH = 955.3 kJ / 0.772 mol.

ΔH = 1237.435 kJ/mol.