3. An acid-base indicator, HIn, dissociates according to the following equation.
In(aq) ⇌ H+(aq) + In-(aq)
colour A colour B
Which statement about this indicator is correct?
I. In a strongly acidic solution colour B would be seen.
II. In a neutral solution the concentrations of HIn- (aq) and In (aq) must be equal.
III. It is suitable for use in titrations involving weak acids and weak bases.