試題詳解

38. In the titration of a weak acid HA with 0.100 M NaOH the stoichiometric point is known to occur at a pH value of approximately 10. Which of the following indicator acids would be best to use to mark the endpoint of this titration?
(A) indicator A, 10^-14
(B) indicator B,iTa= 10^-11  
(C) indicator C,Ka= 10^-8
(D) indicator D, Ka = 10^-6
(E) none of these