Question

Out of the following options, which gases change the colour of damp red litmus paper?

• A. Ammonia and Chlorine
• B. Ammonia and Hydrogen Chloride
• C. Carbon Dioxide and Chlorine
• D. Carbon Dioxide and Sulphur Dioxide

Answer 1

The correct option is A

Ammonia and Chlorine

Alkaline or basic compounds change the color of litmus to blue.

Ammonia being alkaline turns damp red litmus blue.

Chlorine on the other hand bleaches damp red litmus paper to white.