Question

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

Answer 1

A `"combustion"` or `"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(0)` to `C(+IV)`, and oxygen is reduced from `O(0)` to `O(-II)`.

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_7H_16`:

`C_7H_16(l) +11O_2(g) rarr 7CO_2(g) + 8H_2O(l)`

For even-numbered alkanes you have to be a bit devious, and use either half-integral coefficients for `O_2`, cf.

`C_4H_10(g) + 13/2O_2(g)rarr 4CO_2(g) + 5H_2O(l)`

Or double the equation entirely:

`2C_4H_10(g) + 13O_2(g)rarr 8CO_2(g) + 10H_2O(l)`

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

`"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.