Question

Sudha took a small amount of sulphur in deflagrating spoon and heated it over a burner. As soon as it started burning she put it in a gas jar and covered with a lid. After sulphur stopped burning she added a small amount of water in it and dissolved the gas in water by shaking it. She then tested the solution with red and blue litmus paper. What did she observe?

• A. In the solution, the blue litmus paper turned red.
• B. In the solution, the red litmus paper turned blue.
• C. Blue litmus paper turned red and red litmus paper turned blue.
• D. There was no change in the colour of litmus paper.

Answer 1

Answer: (A)

$S+O_2\to S{O}_2$
$S{O}_2+H_{2}O\to H_{2}S{O}_3$
$H_{2}S{O}_3$ is an acid.
Acid turns blue litmus to red litmus.