chemistry homework

Question

How much carbon dioxide is generated when 404 kg of methanol burns perfectly?

Answer 1

Here is the correctly balanced equation for the complete combustion of methanol (CH3OH)

2CH₃OH + 3O₂ ==> 2CO₂ + 4H₂O ... balanced equation

The molar mass of methanol = 32.0 g/mole

Moles in 404 kg = 404 kg x 1000 g / kg x 1 mol / 32.0 g = 12625 moles of methanol

Using the stoichiometry of the balanced equation, we will calculate the moles of CO₂ produced...

12625 mol CH₃OH x 2 mols CO₂ / 2 mols CH₃OH = 12625 moles of CO2 produced

This question didn't ask for mass, but to calculate mass CO₂ produced, we use the molar mass of CO₂..

molar mass CO₂ = 44.0 g / mol

12625 mols CO₂ x 44.0 g / mol = 555500 g = 555.5 kg = 556 kg of CO2 produced (3 sig.figs.)