Question

The melting point of amino acids are higher than the corresponding halo-acids because ?

• A. amino acids exist as zwitter ions resulting in strong dipole-dipole attraction
• B. amino acids are optically active
• C. due to higher molecular mass of $-{NH}_2$ group molecular mass of amino acids is higher
• D. they interact with water more than halo-acids and have salt like structure

Answer 1

Answer: (A)

amino acids exist as zwitter ions resulting in strong dipole-dipole attraction

Amino acids exist as zwitterions resulting in strong dipole-dipole attraction

Amino acids have two functional groups $-N{H}_2$ and $-COOH$. Hence the amino acids exist as a dipolar ion (or) zwitterion. As a result, strong electrostatic forces exist between zwitterions.

Hence amino acids have high melting points than the corresponding halo-acids.