Question

In a highly acidic solution the dominant form of glycine is

Answer 1

Answer:

In a highly basic solution, pH = 13, the dominant form of glycine is: NH2—CH3+—COO-. For amino acids with neutral R groups, at any pH below the pI of the amino acid, the population of amino acids in solution will have: a net positive charge.

Answer 2

Answer:

In a highly acidic solution the dominant form of the glycine will be the cationic form.

Explanation:

• Glycine is an amino acid. Amino acids are the compounds which contain both amino group (basic group) and carboxylic group (acidic group).
• The amino acids are present in the dipolar form within the same molecule is called 'zwitter ion'. It can be shown as ⁺NH₃-CHR-COO⁻.
• Zwitter ion is amphoteric in nature.  In the aqueous solution of amino acids , they exist in equilibrium between the dipolar form, anionic form and cationic form.

        ⁺NH₃-CHR-COOH   ⇄   ⁺NH₃-CHR-COO⁻   ⇄    ⁺NH₃-CHR-COO⁻

            Cationic form                   Dipolar form             Anionic form

• In the acidic solution the concentration of H⁺ ions will be greater. Therefore, they react with carboxylate group and cationic form of glycine will be dominated.

         ⁺NH₃-CH₂-COO⁻  +   H⁺ $\longrightarrow$ ⁺NH₃-CH₂-COOH

                                                           Cationic form.

Therefore, the  cationic form of glycine dominates in acidic solution.