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

1 Answer
Nov 24, 2016

Answer:

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.