Question

Answer the following question: Ethanol, C2H5OH, is considered clean fuel because it burns in oxygen to produce carbon dioxide and water with few trace pollutants. If 150.0 g of H2O are produced during the combustion of ethanol, how many grams of ethanol were present at the beginning of the reaction?

Answer 1

Answer:

127.88 grams of ethanol were present at the beginning of the reaction

Explanation:

Firstly, let's make the combustion reaction:

C₂H₅OH  +  3O₂  →  2CO₂  +  3H₂O

By 1 mol of ethanol, you can make 3 mole of water.

Mole of water = Water mass / Molar mass

150g / 18g/m = 8.3 mole

3 mole of water came from 1 mol of ethanol

8.3 mole came from (8.3 .1)/3 = 2.78 mole of ethanol

Molar mass ethanol = 46 g/m

Mole . molar mass = mass

2.78 m .  46g/m = 127.88 g