Question

How many pi bonds are there in triple bonds?

Answer 1

Alkyne is an unsaturated hydrocarbon which contains at least one carbon-carbon triple bond. The general chemical formula for alkyne is represented as ${{C}_{n}}{{H}_{2n - 2}}$. Alkynes are also known by the name acetylenes and in alkyne n = 1 is not possible.

Complete step by step answer:
- First member of alkyne group is ethyne where n = 2 and ethyne is represented by the chemical formula ${{C}_{2}}{{H}_{2}}$ and alkyne represents the presence of triple bond between two carbon atoms so ethyne can also be expressed as $CH\equiv CH$.
- Pi bonds are generally covalent chemical bonds in which two lobes of an orbital on one atom overlap two lobes of an orbital on another atom and this overlap is done laterally. Each of these atomic orbitals has zero electron density at a shared nodal plane which passed through the two bonded nuclei. Double bond consists of one sigma bond and one pi bond. -We know that chemical or covalent bonds are always made up of one sigma bond but they have extra pi bonds around the central sigma bonds which form double or triple bonds.
Hence we can consider that the triple bond contains one sigma bond and two double bonds.

Note: Pi bonds can form only in double and triple bonds but do not form in single bonds. Pi bonds are generally represented by the Greek letter $\pi$ which refers to p-orbitals and it gives us an idea about the orbital symmetry of the pi bonds is the same as that of p orbitals.