Answer to Question #59006 in General Chemistry for Virginia Collis
The alcohol in "gasohol" burns according to the following equation.
If 25 mol of C2H5OH burns this way, how many moles of oxygen are needed
The amount of substance of Oxygen:
n(O2) = 3 mol *25 mol/1 mol = 75 mol
By the reaction 75 mol of oxygen are needed.