An acid-base indicator is blue at a pH above 8 and yellow at pH below 6.1. Which form of the indicator would be in a greater amount if the solution were blue?

Question

An acid-base indicator is blue at a pH above 8 and yellow at  pH below 6.1. Which form of the indicator would be in a greater amount if the solution were blue?

anonymous · Answer

Sorry, the answers were cannot be determined, H[ln-], H20, [ln-]

anonymous · Answer

@abb0t

anonymous · Answer

@sweetburger

anonymous · Answer

@aaronq

aaronq · Answer

if the indicator is blue in a basic medium, then the deprotonated form would be present in a greater amount than the protonated form.

anonymous · Answer

I'm sorry, I'm really not familiar with titration between acids and bases at all so the information you're giving me doesn't make a whole ton of sense to me.

aaronq · Answer

$\color{red}H[ln^-]$  -> protonated 

 $[ln^-]$ -> deprotonated

aaronq · Answer

as you increase the pH (in other words, decrease $[H_3O^+]$), less of the protonated form of the indicator will be present.

anonymous · Answer

Alright, thankyou, that makes sense(:

aaronq · Answer

good stuff! no problem