Pratyush took sulphur powder on a spatula and heated it.
Question.
Pratyush took sulphur powder on a spatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below.

(a)What will be the action of gas on

(i) dry litmus paper?

(ii) moist litmus paper?

(b)Write a balanced chemical equation for the reaction taking place.

solution:

(a)(i) There will be no action on dry litmus paper.

(ii)Since the gas is sulphur dioxide $\left(\mathrm{SO}_{2}\right)$, it turns moist blue litmus paper to red because sulphur

dioxide reacts with moisture to form sulphurous acid.

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