Question

What is the oxidation number of carbon in ${\mathrm{C}}_3{\mathrm{H}}_8$?

Answer 1

1. The oxidation state or oxidation number is defined as the number of electrons lost or gained in a molecule, element, or compound.
2. It depends upon the outermost valence shell of electrons.
3. The atomic number of carbon is 6 and is represented as “C”
4. The general electronic configuration of carbon is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^2$.

Writing the structural formula and counting the number of atoms

• The structural formula is:

• Propane contains 3 Carbon and 8 Hydrogen atoms.
• Each of the hydrogens will contain a +1 charge and hence the total charge on all hydrogen is equal to 8.

Calculating the oxidation number

• Let us consider the Carbon atom to be “x” and the Propane has 3 atoms of Carbon, so it will be 3x.
• Now, calculate the oxidation state by putting all the atoms equal to 0.
• $$\begin{gathered} 3\mathrm{x}+8=0 \\ 3\mathrm{x}=-8 \\ \mathrm{x}=-\frac{8}{3} \end{gathered}$$
• Therefore the oxidation number of Carbon in Propane is equal to $-\frac{8}{3}$