Question

The correct order of equlibrium constants for the reactions is `H_(2)CO+H_(2)Ooverset(k_(1))hArrH_(2)C(OH)_(2)`
`CH_(3)CH_(2)CHO+H_(2)Ooverset(k_(2))hArrCH_(3)CH_(2)CH(OH)_(2)`
`CH_(3)COCH_(3)+H_(2)Ooverset(K_(3))hArrCH_(3)C(OH)_(2)CH_(3)`
A. `K_(1)gtK_(2)gtK_(3)`
B. `K_(1)ltK_(2)ltK_(3)`
C. `K_(1)gtK_(3)gtK_(2)`
D. `K_(1)ltK_(3)ltK_(2)`

Answer 1

Correct Answer - A
The reaction are known as hydration of `C=O` group. The bulkier the groups attached to the C, greater is trhe steric effect, the higher will be the energy during the energy changes in hybrid state and the equlibrium is more likely to lie towards the unhydrated compound. The +I- effect of alkyl groups also decreases the reactivity of `C=O` towards uncleophilic addition of water. Thus, the trend in equlibrium constants is `K_(1)gtK_(2)gtK_(3).`