What will be the action of the following substances on litmus paper? Dry HCl gas, Moistened 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 |
