Hi,

The combustion of 2.15g of methanol was found to yield 71.5kJ of heat.

Calculate the deltaH value for this value, and write the thermochemical equation.

This is what I have done so far:

2CH3OH(l) + 3O2 --> 2CO2(g) +4H2O(g)

n(CH3OH) = m/M = 3.15/32.04 = 0.098 mol

So 0.098 mol produces 71.5kJ of energy

1 mol produces 71.5kJ/0.098mol = 729.59 kJ?

So deltaH should be -729.59kJmol-1??

But the answer is −1.45×103kJmol−1

Can someone help me clarify where I have gone wrong?

THANK YOU