Hexane (C6H14) reacts completely with oxygen (O2) to make carbon dixode and water. Balance the equation. How many mole of oxygen are consumed per mole of hexane burned?

C6H14 + O2 = CO2 + H2O

Once you balance the equation (it's easy -- balance carbons first, then the hydrogens (use the water produced), and finally the oxygen).

Once you see the balanced equation, you can easily see how much oxygen is consumed for 1 mole of C6H14.