Question

Given the following formula 2 KCIO3 -> 2 KCI + 3 O2 how many moles of O2 can be produced by letting 12 moles of KCIO3 react?

Answer 1

1st you need to find the mole ratio between KClO3 and O2.  To find that you need to take the coefficents of each of the compounds.  That gives a ratio of 2:3.

Now we find out how many each unit is:
2x = 12
x = 6

Now we multiply it by 3 to find the number of moles of O2
3(6) = 18 mol O2.