Determine the amount of oxygen required for the combustion of ethanol, the amount of substance is 1.75 mol.

Let’s compose the reaction equation, find the quantitative ratios of substances.

C2H5OH + O2 = 2CO2 + 3H2O.

According to the reaction equation, there is 1 mole of ethanol per mole of oxygen. Substances are in quantitative ratios 1: 1.

The amount of oxygen and ethanol will be equal.

n (O2) = n (C2H5OH) = 1.75 mol.

Let’s find the volume of oxygen.

V = Vn n, where Vn is the molar volume of gas, equal to 22.4 l / mol, and n is the amount of substance.

V = 1.75 mol × 22.4 L / mol = 39.2 L.

Answer: 39.2 liters.