Question

Which of the following compounds contain all the carbon atoms in the same hybridisation state?

• A. $H_{2}C=C=C{H}_2$
• B. $H_{3}C-C\equiv C-C{H}_3$
• C. $H_{2}C=C=C{H}_2$
• D. $H-C\equiv C-C\equiv C-H$

Answer 1

Answer: (C), (D)

$H-C\equiv C-C\equiv C-H$

Hybridisation of ‘C’ in organic compounds :

Hybridisation is the process of intermixing of valence shell atomic orbitals of an atom to get a new set of orbitals and new sets of orbitals are called hybrid orbitals.

In the given molecules hybridisation of carbon atoms can be found simply by counting the number of sigma bonds around that carbon because there is no lone pair on carbon atom.

$2$ sigma bonds $-sp$

$3$ sigma bonds $-s{p}^2$

$4$ sigma bonds $-s{p}^3$

$A)$ $H-C\equiv C-C\equiv C-H$
$sp$ $sp$ $sp$ $sp$

$\left(B\right)$




In compound $\left(A\right)$ all carbon atoms are $sp$ hybridised.

In compound $\left(D\right)$ all carbon atoms are $s{p}^2$ hybridised.

So, in compounds $\left(A\right)$ and $\left(D\right)$ all carbon atoms have the same hybridisation.

Hence, options $\left(A\right)$ and $\left(D\right)$ are correct.