Phenolphthalein is colorless in its protonated form and pink in its deprotonated form
CHEMISTRY · Subjective · A Level · Chemistry · Acids and bases · Acids and bases
Problem
Phenolphthalein is colorless in its protonated form and pink in its deprotonated form. The indicator’s pKa is 9.3. At what pH will a solution containing phenolphthalein appear exactly halfway between colorless and pink? Report the pH to one decimal place.