Answer to Question #71137 in General Chemistry for Unknown

Question

A 1−g sample of glucose (a common sugar or carbohydrate) was burned in a bomb calorimeter. The temperature of 1.00 × 103 g H2O was raised from 24.6°C to 28.1°C (ΔTw = 3.5°C). Calculate the fuel value of the sugar.

Answer 1

1 calorie is amount of energy needed to raise the temperature of 1g of water by 1°C.
Energy released (by 1g of sugar): 3.5 ∙ 1000 = 3500 cal = 3.5 kcal
1 cal = 4.184 J
Energy (in kJ): 3.5 ∙ 4.184 = 14.644 kJ
Answer:
Fuel Value: 3.5 kcal/g or 14.644 kJ/g
And corresponding: 3.5 Mcal/kg or 14.644 MJ/kg