29Tests Ions GasesMedium1 mark
A blue anhydrous substance is used to test for the presence of water.
When water is added to this substance, it changes colour.
What is the anhydrous substance and what is its colour after the addition of water?
| anhydrous substance | colour after addition of water | |
|---|---|---|
| A | cobalt(II) chloride | pink |
| B | cobalt(II) chloride | white |
| C | copper(II) sulfate | pink |
| D | copper(II) sulfate | white |