1.55 g of penatanol
250ml water
Heat from 10 to 38 degrees
Find hear of combustion
2C5H11OH + 15O2 ==> 10CO2 + 12H2O
mols pentanol = grams/molar mass
q = mass H2O x specific heat H2O x delta T.
mol pentanol = 1.55g/88.15 = about 0.018 mol but you do it more accurately.
dH comb = (q/0.018)*2 = about 3330 kJ or so/mol.