pH of indicator

An acid-base indicator (ka = 3 * 10^-5 ) has red colour in acid form and blue colour in basic form . which is/are correct statements;

(A) 75% red form will exist at pH = 4.05
(B) indicator will show red colour at pH = 3.53
(C) blue at ph=5.6

hw to do such Qs??

2 Answers

262

Aditya Bhutra ·2012-04-05 05:52:13

use the equation ,

HIn â†’ H⁺ + In^-
(acidic) (basic)

K = [H⁺][In^-][HIn]

i did this b4 only..dunno y i cudnt get it then :P
ty

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