Question

When few drops of phenolphthalein are added to a dilute solution of sodium hydroxide a pink colour is produced. What will be the colour of the final mixture when excess of $HCl$ is added to it? (Justify your answer)

Answer 1

The colour of the final mixture when added $HCl$ to it

The colour (pink colour) will disappear.

the reaction between an acid and a base is known as neutralisation in this reaction and acid neutralizes the effect of acid and a base this reaction result in the formation of salt and water and energy in the form of heat is evolved.

Process:

fill half in test tube $HCl$ and two drops of phenolphthalein to it start it continuously. next add Sodium Hydroxide till pink colour appears now add one drop of $HCl$ the pink colour disappears so it is evident that when a solution is acidic it gives no colour this shows that neutralization reaction has occurred