what observations are made when you bubble chlorine into a solution of potassium iodide?
You will see the solution become brownish (if the solution is water) or purple (f the solvent is hexane or carbon tetrachloride).
When bubbling chlorine gas (Cl2) into a solution of potassium iodide (KI), several observations can be made:
1. Color Change: Initially, the solution will be colorless or pale yellow. As the reaction progresses, the solution may turn yellowish-brown or even dark brown.
2. Gas Evolution: Bubbles of gas will be observed rising from the solution. These bubbles are mainly composed of chlorine gas (Cl2).
3. Precipitate Formation: A precipitate of iodine (I2) will start to form. Iodine is less soluble in water than potassium iodide, so it will appear as a solid or a fine suspension in the solution. It typically appears as a darker color precipitate.
4. Odor: Chlorine gas has a distinct and pungent odor, similar to the smell of bleach.
These observations indicate that a redox reaction is occurring. Chlorine oxidizes iodide ions (I-) present in the solution, leading to the formation of iodine as the precipitate. The overall reaction can be represented as:
2KI (aq) + Cl2 (g) ā¶ I2 (s) + 2KCl (aq)
It is important to handle chlorine gas with caution, as it is toxic and can be harmful if inhaled or exposed to skin and eyes. Proper safety measures should be taken when performing this experiment.