Question

What will be the nature of existence of an amino acid (containing one amino and one carboxylic acid group) in solution of pH < $p{K}_{a_1}$ ?

• A. It exists an anion
• B. It exists as cation
• C. It exists as zwitter ion
• D. It exists as neutral species with no charge

Answer 1

Answer: (B)

At low pH (acidic solution) $CO{O}^{-}$ ion acts as the base and accepts proton to form the cation.