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Questions
Give scientific reasons:
α-Amino acids have high melting points compared to the corresponding amines or carboxylic acids of comparable molecular mass.
Why α-amino acids have high melting points compared to the corresponding amines or carboxylic acids of comparable molecular mass?
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Solution
- This is due to the peculiar structure called zwitter ion structure of α -amino acids.
- α-Amino acid molecule contains both acidic carboxyl (–COOH) group as well as basic amino (–NH2) group.
- Proton transfer from the acidic group to the basic group of amino acid forms a salt, which is a dipolar ion called zwitter ion.
Thus, α-amino acids have high melting points compared to the corresponding amines or carboxylic acids of comparable molecular mass.
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