Chemistry - Chemical Equilibrium Question with Solution | TestHub

The equilibrium constant ($K_{eq}$) for hydrate formation depends on the electrophilicity of the carbonyl carbon.

Formaldehyde (A) and Acetaldehyde (C) have high $K_{eq}$ because they lack bulky groups and excessive electron donation.

Cyclopropanone (B) has very high $K_{eq}$ due to the relief of angle strain when the sp² carbon ($120^{\circ }$) changes to sp³ ($109.5^{\circ }$).

Chloral (D) is highly reactive because the three electron-withdrawing chlorine atoms create a massive partial positive charge on the carbonyl carbon.