Test for chlorine gas which observation is expected?

Test for chlorine gas which observation is expected?

• A. Turns limewater cloudy
• B. Damp red litmus blue
• C. Bleaches damp litmus paper
• D. Relights a glowing splint

Answer: (C)

Chlorine gas acts as a bleaching agent. When it meets damp litmus paper, it reacts with the moisture to form hypochlorous acid, an oxidizing bleach, which removes the color from litmus. So damp litmus paper is bleached (loses its color) in the presence of chlorine. The other observations point to different gases: turning limewater cloudy comes from carbon dioxide; damp red litmus turning blue indicates a basic gas like ammonia; and a glow-in-the-splint test would show oxygen present.

Chlorine gas acts as a bleaching agent. When it meets damp litmus paper, it reacts with the moisture to form hypochlorous acid, an oxidizing bleach, which removes the color from litmus. So damp litmus paper is bleached (loses its color) in the presence of chlorine. The other observations point to different gases: turning limewater cloudy comes from carbon dioxide; damp red litmus turning blue indicates a basic gas like ammonia; and a glow-in-the-splint test would show oxygen present.