An automobile gasoline tank holds 42 kg of gasoline. When the gasoline burns, 168 kg of oxygen are consumed and carbon dioxide and water are produced. What total combined mass of carbon dioxide and water is produced?

210 kg

Explanation:

The chemical reaction will look like this:

gasoline + O₂ (oxygen) → CO₂ (carbon dioxide) + H₂O (water) + heat

Now in chemical reactions the quantity of the reactants (gasoline + oxygen) is equal to the quantity of products (carbon dioxide + water), so from this principle we may determine:

combined mass of carbon dioxide and water produced = mass of gasoline + mass of oxygen

combined mass of carbon dioxide and water produced = 42 + 168 = 210 kg