Write and balance the equation for the complete combustion of heptane, C7H16. Phase symbols and energy changes are optional.
The Correct Answer and Explanation is :
The balanced chemical equation for the complete combustion of heptane (C₇H₁₆) is:
[
C_7H_{16} + 11O_2 \rightarrow 7CO_2 + 8H_2O
]
Explanation:
- Understanding Combustion:
- Complete combustion occurs when a hydrocarbon reacts with excess oxygen (O₂) to produce carbon dioxide (CO₂) and water (H₂O).
- If oxygen is insufficient, incomplete combustion may occur, leading to carbon monoxide (CO) or even elemental carbon (C).
- Writing the Unbalanced Equation:
- The general formula for combustion of an alkane (CₙH₂ₙ₊₂) is:
[
C_nH_{2n+2} + O_2 \rightarrow CO_2 + H_2O
] - For heptane (C₇H₁₆), this becomes:
[
C_7H_{16} + O_2 \rightarrow CO_2 + H_2O
]
- Balancing Carbon (C) Atoms:
- Heptane has 7 carbon atoms, so we need 7 CO₂ molecules:
[
C_7H_{16} + O_2 \rightarrow 7CO_2 + H_2O
]
- Balancing Hydrogen (H) Atoms:
- Heptane has 16 hydrogen atoms, which come from 8 H₂O molecules:
[
C_7H_{16} + O_2 \rightarrow 7CO_2 + 8H_2O
]
- Balancing Oxygen (O) Atoms:
- There are 7 CO₂ molecules, contributing 14 oxygen atoms.
- There are 8 H₂O molecules, contributing 8 oxygen atoms.
- Total oxygen needed = 14 + 8 = 22 atoms.
- Since O₂ molecules contain 2 oxygen atoms each, we need 11 O₂ molecules:
[
C_7H_{16} + 11O_2 \rightarrow 7CO_2 + 8H_2O
]
This balanced equation ensures that the number of atoms for carbon, hydrogen, and oxygen is equal on both sides.
Now, I’ll generate an image illustrating this reaction.
Here is the image illustrating the complete combustion of heptane (C₇H₁₆), showing the molecular structures, reaction process, and balanced chemical equation. Let me know if you need any modifications!