Combustion Chemistry Example 1

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

easy

Write the balanced equation for the complete combustion of ethanol (

\text{C}_2\text{H}_5\text{OH}

1
Complete combustion of a hydrocarbon/alcohol produces $\text{CO}_2$ and $\text{H}_2\text{O}$ .
2
Unbalanced: $\text{C}_2\text{H}_5\text{OH} + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O}$ .
3
Balance C: 2 $\text{CO}_2$ . Balance H: 6 H atoms → 3 $\text{H}_2\text{O}$ . Balance O: products have $2(2) + 3(1) = 7$ O. Reactant has 1 O in ethanol, so need 6 more from $\text{O}_2$ → 3 $\text{O}_2$ .
4
$\text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \rightarrow 2\text{CO}_2 + 3\text{H}_2\text{O}$ .

Answer

\text{C}_2\text{H}_5\text{OH} + 3\text{O}_2 \rightarrow 2\text{CO}_2 + 3\text{H}_2\text{O}

Combustion reactions are always exothermic. Complete combustion requires sufficient oxygen and produces only

\text{CO}_2

and

\text{H}_2\text{O}

. Incomplete combustion produces CO or soot (C).

About Combustion

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

What is the difference between complete and incomplete combustion of methane ([formula])? Write equa

Balance the combustion of butane: [formula].

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