How much methanol, in grams, must be burned to produce 767 kJ of heat?

Question

When methanol,  is burned in the presence of oxygen gas,  a large amount of heat energy is released. For this reason, it is often used as a fuel in high performance racing cars. The combustion of methanol has the balanced, thermochemical equation

How much methanol, in grams, must be burned to produce  of heat?

Answer 1

This is the correctly balanced equation:



CH₃OH (l) + 2O₂ (g) → CO₂ (g) + 2H₂O (l)

We are told by this equation and by the given information that that 1mol CH3OH produces 764 kJ of energy.

The molar mass of CH3OH is obtained from the Periodic Table of the Elements and is 32.04 g/mol.

Now we can figure out the mass of CH3OH that is required to produce 767 kJ of energy.

Mass = [767 kJ / 764 kJ/mol] x 32.04 g/mol = 32.17 g required.