| Hydrogen sulphide | Ammonia | Sulphur dioxide | Hydrogen chloride | |
|---|---|---|---|---|
| Shake the gas with red litmus solution | No change | Red litmus becomes blue | No change | No change |
| Shake the gas with blue litmus solution | Blue litmus becomes red | No change | Blue litmus becomes red | Blue litmus becomes red |
| Apply a burning splint to the gas | Burning splint is extinguished | Burning splint is extinguished | Burning splint is extinguished | Burning splint is extinguished |