Question

The structure of $C{{H}_{2}}=C{{H}_{2}}$ is
(A)- Linear
(B)- Planar
(C)- Non-planar
(D)- None of the above

Answer 1

Hint : The carbon atoms in $C{{H}_{2}}=C{{H}_{2}}$ are $s{{p}^{2}}$ hybridized. The hybridization of a molecule tells us about the geometry and shape of the molecule.

Complete step by step solution :
Let’s look at the answer
- The carbon atoms in the given molecule are both $s{{p}^{2}}$ hybridized.
-The shape of $s{{p}^{2}}$ hybridization is triangular planar.
-The carbon atom in the given molecule is linked to 2 sigma bonds to H atoms and one pi bond to another carbon atom.
-The pi bonds are formed by the lateral overlapping. For this the two atoms should be in the same plane for maximum overlap.
-In triangular planar geometry all the four atoms are in the same plane and the bond angles are$120{}^\circ$.
-The geometries of both the carbon atoms in the given molecule are triangular planar which is a planar geometry and the shape is also the same. Since, both the atoms are joined by double bonds so the molecule as a whole is planar.
Hence, the given molecule is a planar molecule.

Structure of ethene
So, the correct answer is “Option B”.

Note : $C{{H}_{2}}=C{{H}_{2}}$is an alkene. In an alkene the single bond lengths and double bond lengths are different. It is also more acidic in nature than the corresponding alkane due to its geometry.