問題詳情

21. Lysine H3N+(CH2)4CH(NH2)COO-(denoted by HR) is an essential amino acid, and its hydrochloride salt ([H3R]Cl2) exists in aqueous solution in the following equilibrium:

When an NaOH solution is added to a certain concentration of [H3R]Cl2 solution, the distribution cocfficients δ(x) of H3R2+, H2R+,  HR, and R- vary with pH as shown on the right. Given that

, which of the following statements is correct?
(A)


(B) At M, [CI-] + [OH-] +[R-] =2[H2R+] +[Na+] +H+]
(C) [H2R+], [HR], and [R-] cannot be in the solution at the same time. 
(D)


(E) At P,[CI-]>[Na+]>[OH-] >[H+]

參考答案

答案：D

統計：A:0,B:0,C:0,D:0,E:1

難度：計算中