Question

How many moles of oxygen are needed to burn 1.33 moles of methyl alcohol (CH3OH)?

2CH3OH + 3O2 2CO2 + 4H2O

Answer 1

A. 0.877 moles

B. 0.997 moles

C. 1.330 moles

D. 1.995 moles

E. 2.660 moles

Answer 2

Well, it takes 3 moles of oxygen to completely burn 2 moles of methyl...

So for every 2 moles of methyl, you need 1.5 times as much oxygen (3 divided by 2)

That makes your ratio 1 : 1.5

You need 1.33 moles of methyl so you multiply both sides of the ratio by 1.33 = 1.33 : 1.995

1.995 moles of oxygen are needed