When 1.020 g of ethanol (C2H6O, 46.07 g/mol) was burned in a bomb calorimeter containing 2400. g of water, the temperature of the water rose from 22.46 to 25.52ºC. The specific heat of water is 4.18 J/g-°C. What is the enthalpy of combustion of 1 mol of ethanol? What is the heat capacity of the calorimeter?
Mass of ethanol = 1.020 g
Molar mass = 46 g/mol
No. of moles = Mass of ethanol / Molar mass = 1.020 g / 46 g/mol = 0.0222 moles
Mass of water = 2400 g
Molar mass of water = 18 g/mol
No. of moles of water = 2400 g / 18 g/mol = 133.33 moles
Specific heat of water Cp = 4.18 J/g.C
Intial Temperature = 22.46 C
FInal temperature T2 = 25.52 C
heat released from ethanol = heat absorbed by water = (m*Cp*(T2-T1)) of water
heat released from ethanol = 2400 g * 4.18 J/g.C ( 25.52 - 22.46) C = 30697.92 J
0.0222 moles of ethanol released 30697.92 J
so Enthalpy of combustion of 1 mole of ethanol = 30697.92 J / 0.0222 moles = 1382.79 KJ//mol Answer
Get Answers For Free
Most questions answered within 1 hours.