Find the amount of heat given off from the combustion of 323.2 g CH3OH

Question

Methanol undergoes combustion according to the equation: 2CH3OH(l) + 3O2(g) ----------> 2CO2(g) + 4H2O(l) ^H = -1,452.8 kJ Find the amount of heat given off from the combustion of 323.2 g CH3OH

additional instructions: answer should be round off to the nearest whole number. don't specify the unit of measurement.

Answer 1

2CH₃OH(l) + 3O₂(g) ----------> 2CO₂(g) + 4H₂O(l ... ∆H = -1,452.8 kJ

This tells us that for 2 moles of CH3OH, the heat liberated is 1452.8 kJ

We will convert 323.3 g CH3OH to moles, and then determine how much heat will be liberated.

molar mass CH3OH = 32.04 g/mol

323.3 g CH3OH x 1 mol / 32.04 g = 10.09 moles CH3OH

Heat given off = 10.09 moles x -1452.8 kJ / 2 moles = -7330 kJ

Rounding to nearest whole number and omitting units, you have -7330 as your answer