Question

What orbitals are used to form 10 sigma bonds in propane( CH ₃CH ₂CH₃₎?

Short answer

In propane 2, sigma bonds are formed by SP³ -SP³overlap and rest eight sigma bonds are formed by the overlap of SP³with s-orbital.

Step-by-step solution

Identifying the type of sigma bonds in propane

InthereCH₃CH₂CH₃ are 10 sigma bonds which consist of 2 C-Cbonds and rest 8 C-Hbonds.

Identifying the orbitals used 

All the bonds in propaneCH ₃CH ₂CH₃are single bonds. To bond with four atoms, each carbon in propane will use 4SP³ orbitals. Among 4 SP³ orbitals, one is used to bond with the SP³ orbital of the next carbon, thus, forming C-Cbond.

The other 3SP³ orbitals are used to bond with s-orbitals of the hydrogen attached to the carbon, thus, forming C-Hbond.

Final conclusion

The 2C-C bonds are formed bySP^3--SP³ overlap and the rest 8 C-Hsigma bonds are formed by SP³-Soverlap.