In a combustion reaction, 46.0g of ethanol reacts with 96.0 g of oxygen to produce water and carbon dioxide. If 54.0 g of water is produced, what mass of carbon dioxide is produced?

The basic law of mass conservation states that, the total mass of products of a chemical reaction should be equal to the total mass of reactants in the same reaction.

Applying this law to the above problem, we find that:

Total mass of reactants = 46 + 96 = 142 grams

This means that the total mass of products (water + carbon dioxide) should be also 142 grams

Since 52 grams of water is produced, therefore,

mass of carbon dioxide = 142 - 52 = 90 grams