Question

At $pH =4$, glycine exists as

• A. $H_{3}\overset{+}{N}-CH_{2}-COO^{-}$
• B. $H _{3} \overset{+}{N} - CH _{2}- COOH$
• C. $H_{2}N-CH_{2}-COOH$
• D. $H _{2} N - CH _{2} - COO^{-}$

Answer 1

Answer: (B)

At $pH =4$, an amphoteric Zwitter ion structure changes into cation when an acid is added to it.