The colour of phenolphthalein in acids is:a)Colourlessb)Redc)Pinkd)BlueCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

The colour of phenopthalin is colourless in acids but becomes pink in bases

Answer

Colourless

Answer

Yes it colourless in acid and pink in base

Answer

Yaa its colourless in acid
pink in bases

Answer

Phenolphthalein is an synthetic indicator.It change it's colour to colourless in acidic solution, and change it's colour to pink in basic solution.

Answer

The colour of phenolphthalein in acids is colourless.
Phenolphthalein is a commonly used pH indicator that is often used in titrations to determine the endpoint of a reaction. It is a weak acid that has the ability to change its colour depending on the pH of the solution it is in.

Phenolphthalein acts as an acid-base indicator, meaning it can undergo a reversible colour change in response to changes in pH. In basic or alkaline solutions, phenolphthalein is pink in colour. This is because in basic conditions, the phenolphthalein molecule accepts a proton (H+) and becomes negatively charged, causing a shift in the electronic structure of the molecule that leads to the formation of a pink colour.

However, in acidic solutions, phenolphthalein is colourless. This is because in acidic conditions, the phenolphthalein molecule donates a proton (H+) and becomes positively charged, which results in a different electronic structure of the molecule that does not produce any visible colour.

This colour change is due to the difference in the ionization states of phenolphthalein in acidic and basic solutions. In acidic solutions, the phenolphthalein molecule is predominantly in its acid form (HIn), which is colourless. In basic solutions, the phenolphthalein molecule is predominantly in its ionized form (In-), which is pink.

Therefore, when phenolphthalein is added to an acid, it remains colourless because the solution is acidic and the acid form of phenolphthalein is dominant. However, when it is added to a base, it turns pink because the solution is basic and the ionized form of phenolphthalein is dominant.

In conclusion, the colour of phenolphthalein in acids is colourless, while in bases it is pink. This property makes phenolphthalein a useful indicator in acid-base titrations to determine the endpoint of a reaction.

Answer

It is synthetic indicator,  colourless due to acid

Similar Class 10 Doubts

What is the colour of phenolphthalein in soap solution?

Acids change the colour of methyl orange to

What is the colour of phenolphthalein in soap solution?

When a few drops of phenolphthalein are added to a solution of NaOHpink colour is produced. What will be the colour of the final mixture when excess of HCl is added to it?

Top Courses for Class 10View all

Science Class 10

Social Studies (SST) Class 10

Mathematics (Maths) Class 10

English Grammar Advanced

English Grammar Basic

Top Courses for Class 10

Top Courses for Class 10

Suggested Free Tests

Related Content

About Class 10

Class 10 Study Material

Class 10 All Subjects

NCERT Textbook Solutions

Other Classes

Important Links

Company