Question

Two drops of the indicator phenolphthalein were added to 10ml solution of sodium hydroxide.

Write down the changes that will be seen in each instance and explain the reason behind it.

(b) Two drops of the indicator phenolphthalein were added to 10ml solution of sodium hydroxide.

Answer 1

When two drops of Phenolphthalein indicator are added to 10 mL solution of Sodium hydroxide,  then the solution turns light pink in colour

because the acidic part of phenolphthalein reacts with the base, it forms sodium salt of phenolphthalein which has pink color.

Phenolphthalein is an indicator used for determining the quantity of base.