posted by Anonymous .
An indicator has the reaction Hln(aq) ¡ê H+(aq) + In-(aq). Explain how the indicator can change color when a strong base is poured into a solution of this indicator. Will a strong base dissociate? Which way will this cause the reaction to shift? Is there more or less HIn? Do HIn and In- have the same color? Will the solution change color when a strong acid is poured into it? Why?
HIn ==> H^+ + In^-
When a strong acid is added, it shifts the equilibrium to the left. Indicator work because the HIn is one color (or no color) and the In is a different color (or no color).