question_answer 4)

The melting points and solubility in water of amino acidsare generally higher than that of the corresponding halo acids. Explain. Higher the polarity of a group, more is its solubility in water.  

Answer:

Amino acids are dipolar in nature  andhave strong dipolar interactions. Therefore, these have high meltingpoints. When dissolved in water, these form hydrogen bonds with watermolecules, therefore, these are soluble in water, (except at isoelectricpoint, where they have least solubility) In case of halo acids, these arenot dipolar. Only their carboxyl group is involved in hydrogen bonding,not the halogen atom. Therefore, halo acids, have lower melting pointsand lesser solubility than amino acids.