Calculating CO2 Production from Octane Combustion: A Comprehensive Guide

The combustion of octane (C8H18) is a significant source of carbon dioxide (CO2) in the environment. This process involves a balanced chemical reaction that can be analyzed using stoichiometry to determine the amount of CO2 produced. Here, we will walk through a detailed example to illustrate the steps for calculating the grams of CO2 produced from the combustion of 15.0 gallons of octane.

Understanding the Chemical Reaction

The balanced chemical equation for the combustion of octane is:

2 C8H18 25 O2 → 16 CO2 18 H2O

From this equation, we can see that two moles of octane react with 25 moles of oxygen to produce 16 moles of CO2 and 18 moles of water.

Step 1: Convert Gallons to Liters

To begin the calculation, we need to convert the volume of octane from gallons to liters. Using the conversion factor:

15.0 gallons × 3.785 L/gal 56.785 L

Step 2: Calculate Moles of Octane

Next, we need to determine the moles of octane using its molar mass. The molar mass of octane is calculated as follows:

Carbon (C): 12.01 g/mol × 8 96.08 g/mol

1.008 g/mol × 18 18.144 g/mol

Total molar mass of C8H18: 96.08 18.144 114.224 g/mol

Using the density of octane (0.703 g/mL or 703 g/L), we can convert liters to grams:

mass of C8H18 56.785 L × 703 g/L ≈ 39943.455 g

Now, we can convert grams to moles:

moles of C8H18 39943.455 g / 114.224 g/mol ≈ 349.4 moles

Step 3: Use Stoichiometry to Determine Moles of CO2

The balanced equation shows that 2 moles of octane produce 16 moles of CO2. Therefore, the mole ratio of C8H18 to CO2 is:

16 moles CO2 / 2 moles C8H18 8

To find the moles of CO2 produced:

moles of CO2 349.4 moles C8H18 × 8 2795.2 moles CO2

Step 4: Calculate the Mass of CO2

The molar mass of CO2 is calculated as follows:

Carbon (C): 12.01 g/mol

Oxygen (O): 16.00 g/mol × 2 32.00 g/mol

Total molar mass of CO2: 12.01 32.00 44.01 g/mol

Now, we can calculate the mass of CO2 produced:

mass of CO2 2795.2 moles × 44.01 g/mol ≈ 123000 g

Converting this to kilograms:

123000 g 123 kg

Conclusion

In summary, the combustion of 15.0 gallons of octane produces approximately 123 kg of CO2. This process is a significant contributor to the global carbon footprint, highlighting the importance of understanding and mitigating such emissions.

Keywords

- CO2 production
- Octane combustion
- Chemical reactions
- Stoichiometry