Question

Question 9 (a)

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

What will be the action of gas on:

(i) dry litmus paper?

(ii) moist litmus paper?

Answer 1

Sulphur reacts with oxygen to form sulphur dioxide gas. The reaction occurs as follows:

$\text{S (s)}+{\text{O}}_2\text{(g)}\to {\text{SO}}_2\text{(g)}$

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

(ii) The colour of blue litmus paper will turn red because sulphur is a non-metal and the oxides of non-metal are acidic in nature.