Is phenolphthalein a acid or base?

Answer 1

It is a property of phenolphtalein to be colorless in acid and purple in base (alkaline), above pH 8.2 - 10

Answer 2

The phenolphthalein molecule is colorless but the phenolphthalein ion is pink.

When a base is present in a solution containing phenolphthalein, the molecule to ions equilibrium shifts to create more (pink) ions than (colorless) molecules.

Answer 3

Phenolphthalein is an acid-base indicator that turns pink in an alkaline solution,and this feature is due to the ions it dissociate into in such a medium,for illustration lets take the ions that phenolphthalein is made up of as Hln such that it dissociate in aqueous medium into H+ and ln-,when placed in an alkaline medium the substance dissociates into H and OH ions,since the OH ions is in excess,it cause dissociation of the Hln into it`s ions,the H ion from the phenol is paired with the OH of the medium causing more dissociation,hence visible pink color,because the left Ln ion is the real pink colored ion.

NOTE:color change intensity of indicators is affected by extent of dissociation which is also dependent on amount of hydrogen or hydroxide present

Answer 4

I'd like to correct the question, cause phenolphalein is turns colorless in acidic solutions and pink in basic solutions .

Answer 5

Pink in basic, colourless in acidic and neutral

If you are really mad and want to know the colour for less that pH 0, its red.

Answer 6

Phenolphthalein is neither acid nor base. It is an indicator to detect whether the solution is acid or base.

Answer 7

It will be colorless in an acidic solution and red in a basic solution.

Answer 8

Phenolphthalein in acidic solutions (under pH=8): colorless.
Phenolphthalein in basic solutions (pH= 10 to 13): fuchsia.

Answer 9

Pink to red, depending on concentration.

Answer 10

Pink to red in acid, clear in alkali.