CHEMISTRY · Single correct · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Methyl orange has pKa=3.7. In its protonated form the indicator appears red, whereas in its deprotonated form it appears yellow. What is the most likely color of a solution that contains methyl orange at pH=2.5?
(a) Yellow
(b) Red
(c) Colorless
(d) Orange (equal mix of red and yellow)