Question

The aqueous solution of substance A, B and C are taken in three test tubes respectively. Solution of
substance A turned reddish, when a few drops of methyl orange were added to it. Solution of substance C
changed to pink colour when a few drops of phenolphthalein were added to it. While solution of
substance did not show any change in colour either with methyl orange or phenolphthalein. State the
nature of solution A, B, and C.
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Answer 1

Answer:-

Given:-

Aqueous solutions of three substances A , B , C are taken in three different test tubes.

And,

• A changes to red when methyl orange is added.
• B changes to pink when phenolphthalein is added.
• C doesn't show any change in its colour either methyl orange and phenolphthalein are added.

Before checking each of the test tubes, we have to keep in mind that:

• A substance is acidic when it changes to reddish when methyl orange is added to it.

• A substance is basic when it changes to pink when phenolphthalein indicator is used.

• If a substance doesn't show any change in its colour either methyl orange or phenolphthalein, it is neutral in nature.

We are given that:

1) A changes to red in methyl orange.

Hence, we can say that A is acidic in nature.

2) B changes to pink in phenolphthalein.

Hence, B is basic nature.

3) C does not show any change.

So, C is neutral in nature.