Properties of Water
- Compound of Hydrogen and Oxygen - Hydrogen Oxide
- Colourless, odourless liquid at room temperature
- Solid water is ice and gaseous water is steam.
- Good Solvent
Water Of Crystallisation
Water that is chemically bonded into a crystal structure
Water of crystallisation is present
Removal of water of crystallisation
Water of crystallisation is not present
Heating Copper Sulfate Crystals
When copper sulfate crystals are heated...
Colour change: blue to white
Equation: CuSO4 . 5H2O > CuSO4 + 5H2O
- Condensation on test tube
- Steam from mouth of test tube
Three Tests for Water
1. Anhydrous Copper Sulfate - white to blue
2. Cobalt Chloride Paper - blue to pink
3. Melting and boiling point tests
(1 and 2 are chemical tests)
Testing water for hardness
1. Measure out 25cm3 of water using a pipette
2. Add water to a conical flask
3. Add a little soap solution from a burette, shaking the flask.
4. Add more soap solution, a little at a time, until a lather lasting at least 30 seconds is obtained.
5. Record the volume of the soap solution used.
6. Repeat the procedure of each water sample: distilled, tap water, bottled water and boiled tap water.