Mole conversion practice

Question

1. In the equation 2 Al₂O₃  ---> 4Al+3O_2, how many moles of oxygen are produced when 6 mol of Al₂O₃ decompose completely?

Answer 1

First, check the given equation and make sure it is balanced.

 

Next, determine the mole-to-mole ratio you need to answer the given question. Since the equation is balanced, we see that for every 2 moles of Al₂O₃ 3 moles of O₂ are produced, assuming the reactant is completely consumed/decomposed.

 

Then, we set it up using the mole-to-mole ratio as a conversion factor. 

 

6 mol Al₂O₃ x  (3 mol O₂ / 2 mol Al₂O₃) = 9 mol O₂

 

The "old" units (mol Al₂O₃) cancel, leaving our new units (mol O₂).