# The burning of fuels, such as coal, natural gas, or oil, involves what type of reaction?

Nov 24, 2016

A $\text{combustion}$ or $\text{oxidation reaction}$.

#### Explanation:

The burning of coal or hydrocarbons is certainly an example of an oxidation reaction, in which, for combustion of coal, carbon is oxidized from $C \left(0\right)$ to $C \left(+ I V\right)$, and oxygen is reduced from $O \left(0\right)$ to $O \left(- I I\right)$.

The combustion of methane, or indeed of any hydrocarbon, is simple to accomplish, and very simple to represent: balance the carbons; then the hydrogens; and then the oxygens.

For heptane, ${C}_{7} {H}_{16}$:

${C}_{7} {H}_{16} \left(l\right) + 11 {O}_{2} \left(g\right) \rightarrow 7 C {O}_{2} \left(g\right) + 8 {H}_{2} O \left(l\right)$

For even-numbered alkanes you have to be a bit devious, and use either half-integral coefficients for ${O}_{2}$, cf.

${C}_{4} {H}_{10} \left(g\right) + \frac{13}{2} {O}_{2} \left(g\right) \rightarrow 4 C {O}_{2} \left(g\right) + 5 {H}_{2} O \left(l\right)$

Or double the equation entirely:

$2 {C}_{4} {H}_{10} \left(g\right) + 13 {O}_{2} \left(g\right) \rightarrow 8 C {O}_{2} \left(g\right) + 10 {H}_{2} O \left(l\right)$

In either instance, there must be mass balance, i.e

$\text{garbage in equals garbage out}$.

Now not only is mass stoichiometrically balanced, but energy may also be treated as a stoichiometric product of these combustion reactions.

When a hydrocarbon is combusted, the formation of STRONG $C = O$ and $O - H$ releases energy. These energies are extensively tabulated, and thus the energy output of a given combustion reaction may be predicted and calculated.