Question

When 1328 J of heat energy is added to 40.4 g of ethanol, C 2 H 6 O , the temperature increases by 13.4 ∘ C. Calculate the molar heat capacity of C 2 H 6 O .

Answer 1

The molar heat capacity of C₂H₆O = 2.797 J/g·°C

Step-by-step explanation:

The known parameters are first listed as follows from reading the question

Heat transferred, H = 1328 J

Mass of the heated ethanol, m = 40.4 g

Increase in temperature of the heated gas = ΔT = 13.4 °C

Molar mass of ethanol = 46.07 g/mol

Number of moles of ethanol = 40.4/46.07 = 0.877 moles

The heat required to raise the temperature of 40.4 g of ethanol by 13.4 °C is 1328 J

Therefore we have H = m·c·ΔT

c = specif heat capacity = H ÷ (m·ΔT) =
`(1328)/(40.4*13.4)` = 2.453 J/g·°C

Therefore the heat required to raise the temperature of one mole of ethanol by one degree C =
`(2.453)/(0.877)` J/g·°C = 2.797 J/g·°C

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