Combustion Chemistry Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

medium
What is the difference between complete and incomplete combustion of methane (CH4\text{CH}_4)? Write equations for both.

Solution

  1. 1
    Complete combustion (excess O2\text{O}_2): CH4+2O2→CO2+2H2O\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}.
  2. 2
    Incomplete combustion (limited O2\text{O}_2): 2CH4+3O2→2CO+4H2O2\text{CH}_4 + 3\text{O}_2 \rightarrow 2\text{CO} + 4\text{H}_2\text{O} (produces carbon monoxide).
  3. 3
    Or with even less oxygen: CH4+O2→C+2H2O\text{CH}_4 + \text{O}_2 \rightarrow \text{C} + 2\text{H}_2\text{O} (produces soot/carbon).

Answer

Complete: CH4+2O2→CO2+2H2O\text{Complete: CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}
Incomplete combustion is dangerous because carbon monoxide (CO) is a colorless, odorless toxic gas. It also releases less energy than complete combustion.

About Combustion

A rapid exothermic chemical reaction in which a fuel reacts with oxygen gas, releasing large amounts of energy as heat and light.

Learn more about Combustion →

More Combustion Examples

Example 1 easy

Write the balanced equation for the complete combustion of ethanol ([formula]).

Example 3 easy

Balance the combustion of butane: [formula].

Example 4 hard

Ethanol ([formula]) is used as a fuel additive. Write the balanced equation for its complete combust

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