Question

The reason for the loss of optical activity of lactic acid when OH group is changed by H is that :
(a) Chiral centre of the molecule is destroyed
(b) Molecule acquires asymmetry
(c) Due to change in configuration
(d) Structural change occurs

Answer 1

Hello dear,

● Answer -
(a) chiral centre of the molecule is destroyed

● Explanation -
- In lactic acid, middle carbon atom acts as chiral centre with 4 different functional groups (-H, -OH, -CH3, -COOH) attached to it.
- When -OH group is exchanged by -H, lactic acid converts to propanoic acid with no chiral centre in it. (Since there are two -H on middle carbon).
- Hence, lactic acid loses its optical activity.

Hope this helped...