Question

When few drops of phenolphthalein are added to 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

Hint: The reaction between an acid and a base is known as neutralization resulting in the formation of salt and water and energy in the form of heat is evolved.
Step by step solution: This process is done in titration. - NaOH (sodium hydroxide) is a base, phenolphthalein is added and the base turns pink in colour. After titrating out the base by any acid (drop by drop from the burette) the base gets colourless again. Titration should be in a very cautious way, a single drop difference could spoil our whole experiment.

Complete answer:
Potassium permanganate and water are made up of tiny particle, such that particle of water are colorless and particle of potassium permanganate have color, such that when particle of potassium permanganate kept in water, it gets break down into smaller pieces, hereby occupy the spaces between water molecule and imparting purple color to water.

Hence, the answer to the above question is option C.

Additional Information:
Titration is a technique where a solution of known concentration is used to determine the concentration of an unknown solution. Usually, the titrant (detected solution) is added to the known volume of the assay (unknown solution) until the reaction is complete. Knowing the amount of title added allows you to determine the concentration of the unknown. Often, a pointer is usually used to indicate the end point of a response.
The reaction type provides us with a simple way of dividing titrimetry into the following four categories:
(1) Acid-base titration,
(2) Complexometric titrations,
(3) Redox titrations, and
(4) Precipitation titration.

Note: Neutralization is basically done to modify an acid or base water flow to a neutral pH (approximately 7). This process is maintained rigorously in waste water in all of the industrial sectors. Phenolphthalein is a weak acid, which is why when it is added to a strong base, it gives a pink color and the color intensifies as the pH of the base increases.