Question

Question: What orbitals are used to form each of the C-C and C-H bonds in ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}$ (propane)? How many bonds are present in this molecule?

Short answer

Answer

The sp³-sp³ hybrid orbitals are used for the formation of each C-C bonds in propane. The orbitals used for the formation of C-H bonds in propane are the sp³ orbital of carbon with 1s orbital of hydrogen.

Ten sigma (σ ) bonds are present in this molecule.

Step-by-step solution

Step-by-Step Solution Step 1: Structure of propane

The molecular formula of propane is${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_3$.

Structure of propane

Orbitals used for the formation of C-C and C-H bonds

In propane, all the carbon atoms are ${\mathrm{sp}}^3$ hybridized.

Each C-C bond in propane is formed by overlapping of ${\mathrm{sp}}^3-{\mathrm{sp}}^3$hybrid orbitals, whereas the overlap of ${\mathrm{sp}}^3$ orbital of carbon with 1s orbital of hydrogen causes the formation of each C-H bond.

Number of sigma bonds in propane 

From its structure, the propane molecule is saturated,and four sigma bonds are obtained from each carbon.

Thus, the total number of sigma atoms present in propane is ten