Question

state the observation when dilute hydrochloric acid is added to phenopthalein solution​

Answer 1

Question :)

State the observation when dilute hydrochloric acid is added to phenolphthalein solution​

Answer :)

• Phenolphthalein is a weak acid, which is why when it is added in a strong base, it gives pink color and the color gets intense as the PH of the base increases.

• Phenolphthalein is an indicator which shows colour change(colourless to pink) only in the pH range 8.2 to 10.0. In acidic medium, Phenolphthalein is colourless.

• So, considering that the alkaline Phenolphthalein solution is having pH greater than 8 but less than 10 i.e. the alkaline Phenolphthalein solution is pink in colour, when dilute H2S04 is added to this solution it will slowly become pale pink and then if adding of dilute H2SO4 is continued, then the solution will be colourless.

• If a strong acid such as HCL is added in this solution, it with react with base and cause neutralization. By adding HCL in the solution, the pink color of  phenolphthalein will disappear. This is also called Acid- Base Titration.