33. What will be the action of the following substances on litmus paper?
Dry HCl gas, Moist ened NH₃ gas, Lemon juice, Carbonated soft drink, Curd, Soap solution.
| Substance | Action on Litmus paper |
|---|---|
| Dry HCl gas | No change |
| Moistened NH₃ gas | Turns red to blue |
| Lemon juice | Turns blue to red |
| Carbonated soft drink | Turns blue to red |
| Curd | Turns blue to red |
| Soap solution | Turns red to blue |
Steps: Dry HCl gas has no moisture so it won't affect litmus; moistened NH₃ produces NH₄OH which is basic and turns red litmus blue; lemon juice, carbonated drinks and curd are acidic and turn blue litmus red; soap solution is basic and turns red litmus blue.