Question

Consider the unbalanced equation for the combustion of hexane:

2C6H14(g)+19O2(g)→12CO2(g)+14H2O(g)Determine how many moles of O2 are required to react completely with 7.9 moles C6H14.

Answer 1

The balanced equation is C6H14(g) + 19/2O2(g) → 6CO2(g) + 7H2O(g). If you are given 7.9 moles C6H14, multiply it by a ratio of 19/2/1 to get the moles of oxygen. Then, you will get 75.05 moles of O2.