Consider the balanced equation for the combustion of heptane: C7H16(g) + 11 O2(g) → 7 CO2(g) + 8 H2O(g). How many moles of O2 are required to react completely with 4.8 moles of C7H16?

• A. 48.0 moles
• B. 44.0 moles
• C. 52.8 moles
• D. 33.6 moles

Answer: (C)

Verified step by step guidance

1. Identify the balanced chemical equation for the combustion of heptane: $C_7{H}_{16}\left(g\right)+11O_2\left(g\right)\to 7{\mathrm{CO}}_2\left(g\right)+8H_{2}O\left(g\right)$.
2. Determine the mole ratio between heptane ($C_7{H}_{16}$) and oxygen ($O_2$) from the balanced equation. The ratio is 1 mole of $C_7{H}_{16}$ to 11 moles of $O_2$.
3. Use the mole ratio to set up a proportion to find the moles of $O_2$ needed for 4.8 moles of $C_7{H}_{16}$: $\frac{11}{1}$ = $\frac{x}{4.8}$.
4. Solve the proportion for $x$, which represents the moles of $O_2$ required. Multiply both sides of the equation by 4.8 to isolate $x$: $x=11\times 4.8$.
5. Calculate the product to find the number of moles of $O_2$ required for the complete combustion of 4.8 moles of heptane.