1. Odor:

- Chlorine gas has a distinct, pungent, and irritating odor that resembles bleach.

- Caution: Never rely solely on smell to detect chlorine gas as it can be harmful at low concentrations.

2. Litmus Paper:

- Wet a piece of blue litmus paper.

- If chlorine gas is present, the paper will turn red.

3. Starch-Iodide Paper:

- This paper is impregnated with starch and potassium iodide.

- Chlorine gas will react with iodide ions, releasing iodine, which turns the paper blue.

4. Chlorine Gas Detector:

- Commercial chlorine gas detectors are available, which can accurately measure chlorine concentrations.

5. Chemical Tests:

- Reaction with sodium thiosulfate: Chlorine gas reacts with sodium thiosulfate solution, resulting in the formation of sodium chloride and sulfuric acid.

- Reaction with potassium iodide: Chlorine gas reacts with potassium iodide solution, releasing iodine, which can be detected by its characteristic brown color.

Safety Precautions:

- Never rely solely on smell to detect chlorine gas.

- Wear appropriate personal protective equipment (PPE), including a respirator, gloves, and eye protection.

- Work in a well-ventilated area.

- If chlorine gas is detected, evacuate the area immediately.

- Seek professional assistance from a qualified chemist or safety personnel.

Note:

- Chlorine gas is a toxic and corrosive substance.

- It is crucial to handle chlorine gas with extreme caution and follow all safety guidelines.

- If you suspect chlorine gas exposure, seek immediate medical attention.