The sugar arabinose, C5H10O5, Molar Mass = 150.15 g/mole, was completely combusted with excess oxygen in a calorimeter. Combustion of a 0.548 g sample of arabinose caused the temperature to increase from 20.00 degrees C to 20.54 degrees C in a calorimeter with a total heat capacity of 15.8 kJ/degrees C. Calculate the enthalpy of combustion for arabinose.

Answer 1

Since no mass of water is given I assume the "total heat capacity of 15.8 kJ/degrees C" includes calorimeter + waters.

q = 15.8 kJ/C x delta T is heat in kJ.
If you want that per gram, divide q by 0.548 then per mole by multiplying that by molar mass arabinose.

Answer 2

2337.7