Question

In which 0.01 M solution is phenolphthalein pink?

(1) CH3OH(aq) (3) CH3COOH(aq)
(2) Ca(OH)2(aq) (4) HNO3(aq)

Answer 1

Phenolphthalein is chemical compount. It becomes colorless when it is immersed in acidic solution and pink when immersed in basic solution.

(1) CH3OH(aq) - Methanol. It is a weak acid but has basic properties too.
(3) CH3COOH(aq) - hydrated acetic acid
(2) Ca(OH)2(aq) - Calcium hydroxide or lime water. Basic solution
(4) HNO3(aq) - Nitric acid

Phenolpthalein becomes pink in 0.01M of 2) Ca(OH)2(aq) solution.