Question

What is the shape of ethene molecule?
A) Planar
B) Tetrahedral
C) Bipyramidal
D) None of these

Answer 1

It is easy to identify the shape of a molecule if we know the hybridization of that molecule. Alkanes, Alkenes and Alkynes are the hydrocarbons that contain bonds between carbon and hydrogen atoms.

Complete step by step answer:
We have to know that the ethene has a molecular formula ${C_2}{H_4}$. It has a double bond and therefore belongs to alkene.
We can write the general formula of Alkene as: ${C_n}{H_{2n}}$
We need to know that the electronic configuration of C in ground state: $1{s^2}2{s^2}2{p^2}$
Excitation of electron from s orbital to vacant p orbital so,
We must know that the electronic configuration of C in excited state: $1{s^2}2{s^1}2{p^3}$
Therefore, Hybridization of Ethene= $s{p^2}$ one electron will be unpaired that is an unhybridized orbital and 3 $s{p^2}$orbitals.
We need to remember that the ethene has geometry is Planar
We can draw the structure of ethane molecule as,

Option A) this is a correct option as the molecule has a planar shape as it has $s{p^2}$ hybridization.
Option B) This is an incorrect option as tetrahedral geometry is for $s{p^3}$ hybridization.
Option C) this is an incorrect option as bipyramidal geometry has a hybridization of $s{p^3}d$.
Option D) this is an incorrect option as we got a correct option as ethene has planar shape.

Hence, the correct answer is, ‘Option A’.

Note: We need to remember that the ethane has molecular formula ${C_2}{H_6}$; Ethene has a molecular formula ${C_2}{H_4}$ and ethylene has molecular formula ${C_2}{H_2}$ having slightly sweet smell. We need to know that the ethylene is a nonpolar molecule and soluble in non-polar solvents.