The colour of the neutral litmus solution is .

You are provided with aqueous solutions of three salts $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$. $2‐3$ drops of blue litmus solution, red litmus solution and phenolphthalein were added to each of these solutions in separate experiments. The change in colour of different indicators were recorded in the following table:

On the basis of above observations, identify $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ from the following options:

Pratyush took sulphur powder on a spatula and heated it. He collected the evolved by inverting a test tube over it. What will be the action of gas on the following?

Dry litmus paper.

Pratyush took sulphur powder on a spatula and heated it. He collected the evolved by inverting a test tube over it. What will be the action of gas on the following?

Moist litmus paper.

Which of the following is not an olfactory indicator?

Vankarbhaibhas explained the definition of an acid and a base, given by Robert Boyle in the classroom. Then the students of the classroom gave some suggestions regarding acid and base. Which suggestion is wrong among these?

Prashant: Acids are sour in taste and bases are bitter.

Dhruvi: Acid does not give any effect on wet blue litmus paper while base turns blue litmus paper blue.

Seil: Acid liberates dry hydrogen gas $\left({\mathrm{H}}_2\right)$ by the reaction with the metal. The base does not react with all metals.

Jaydeep: By neutralisation reaction between acid and base, salt and water is produced.

The salt solution which does not react with ammonium hydroxide is: