Chemistry – Chemistry of the environment - Water | e-Consult

Apparatus:

• Anhydrous cobalt(II) chloride (CoCl₂)
• Beaker (e.g., 50 cm³)
• Dropper

Procedure:

1. Place a small amount of anhydrous cobalt(II) chloride (approximately 1-2 cm³) into a clean, dry beaker.
2. Carefully add a few drops of distilled water to the cobalt(II) chloride in the beaker.
3. Observe the cobalt(II) chloride solution for any colour change.

Expected Observations:

The anhydrous cobalt(II) chloride will turn from a white colour to a pale blue colour. This indicates the presence of water, as the water reacts with the cobalt(II) chloride to form hydrated cobalt(II) chloride (CoCl₂·xH₂O), which is blue.