Question

Describe a chemical test for water.

Answer 1

 1) Water or its vapour will turn cobalt chloride paper from blue to pink. anhydrous copper(II) sulfate crystals from white to blue. 3) Water melts at 0°C and boils at 100 °C.

Answer 2

To test water we can use Ph Test and Boiling Test.

Ph Test:

• We use a blue/red litmus paper to perform this test.
• The Ph of water = 7. It is neutral
• When dipped in water, blue litmus will remain blue and red litmus will remain red.
• This result indicates no acid or alkali is present in the tested liquid hence it can be determined to be neutral i.e water.

Boiling Test:

• We need a tungsten burner and a thermometer for this test.
• The b.p (boiling point) = 100°C
• The test will include heating the liquid while constantly reading the temperature in the thermometer.
• If the liquid starts to boil (bubbles rise from the bottom of the liquid container to the surface level of the liquid) at the perfect temperature of 100°C, the liquid is water.