# Homework Help: Calculate the mass of CO2 produced from the complete combustion

1. Sep 20, 2009

### Zhalfirin88

1. The problem statement, all variables and given/known data
Gasoline consists primarily of octane, C8H18

Calculate the mass of CO2 produced from the complete combustion of 3.79 L (1.00 gallon) of gasoline (assume octane, density = 0.756 g/mL) with excess O2

3. The attempt at a solution
The balanced chemical formula would be:

2C8H18 + 25O2 $$\rightarrow$$ 16CO2 + 18H2O

For my work:

$$3790mL (octane)* \frac{0.756g(octane))}{mL} * \frac{1 mol (octane)}{114.144g (octane)} * \frac{8 mol (CO_2)}{1 mol (octane)} * \frac {44.00g CO_2}{1 mol CO_2}$$

$$= 8835.8957g CO_2$$

Is it correct? What about significant figures?

Last edited: Sep 20, 2009
2. Sep 20, 2009

### Bohrok

Re: Stoich

Looks correct. Since you start with a number with 3 significant figures and use a conversion factor with 3 sig figs, use three in your answer.