When 22.8 g of carbon were burned in the presence of 78. 9 g of oxygen 18.1 g of oxygen remained unreacted what mass of carbon dioxide was produced

Explanation:

We are given the masses of two reactants and asked to determine the mass of the product.

This looks like a limiting reactant problem.

1. Assemble the information

We will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

MM:           12.01        32.00   44.01

                    C      +      O₂ ⟶ CO₂  

Mass/g:     22.8          78.9  

2. Calculate the initial moles of C

We know that there is excess oxygen, so C is the limiting reactant.

3. Calculate the moles of CO₂ formed

4. Calculate the mass of CO₂