B.1.1 Calculate the energy value of a food from enthalpy of combustion data
Food is combusted in a bomb calorimeter.
E.g.) 18.0 of a 180.0 g apple was completely combusted. The temperature of 300.0 g of water was raised by 50.0
°C. If the calorimeter heat capacity was 89.1 J/°C, calculate the calorific value of the apple.
Q = (mH2O)(CspH2O)(∆TH2O) + (Ccal)(∆Tcal)
Q = (300.0)(4.18)(50.0) + (89.1)(50.0)
Q = 67155 J
Q = 672 kJ
Food is combusted in a bomb calorimeter.
E.g.) 18.0 of a 180.0 g apple was completely combusted. The temperature of 300.0 g of water was raised by 50.0
°C. If the calorimeter heat capacity was 89.1 J/°C, calculate the calorific value of the apple.
Q = (mH2O)(CspH2O)(∆TH2O) + (Ccal)(∆Tcal)
Q = (300.0)(4.18)(50.0) + (89.1)(50.0)
Q = 67155 J
Q = 672 kJ