Question

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

Answer 1

Hint: 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: $$1s^{2}2s^{2}2p^2$$
Excitation of electron from s orbital to vacant p orbital so,
We must know that the electronic configuration of C in excited state: $$1s^{2}2s^{1}2p^3$$
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.