Question

Объясните изменение окраски фенолфталеина

Answer 1

Сам раствор фенолфталеин не имеет цвета, т.е. является бесцветным.
В соединении с кислотой, фенолфталеин становится малиновым (или бордовым) в зависимости от количества.

Answer 2

Explanation of Phenolphthalein Color Change

Phenolphthalein is a chemical compound commonly used as an acid-base indicator. It undergoes a color change depending on the pH of the solution it is in. The color change occurs due to the structural changes that phenolphthalein undergoes when it interacts with different pH levels.

Phenolphthalein is colorless in acidic solutions with a pH below 8.2. In this acidic environment, the phenolphthalein molecule exists in a protonated form, where hydrogen ions (H+) are attached to specific atoms in the molecule. This protonated form of phenolphthalein does not absorb visible light, resulting in a colorless appearance.

When the pH of the solution becomes basic, above 8.2, the phenolphthalein molecule undergoes a structural change. The hydrogen ions dissociate from the molecule, causing it to become deprotonated. In this deprotonated form, the phenolphthalein molecule absorbs visible light in the range of 540-580 nm, which corresponds to a pink color. Therefore, in basic solutions, phenolphthalein appears pink.

The color change of phenolphthale