Required Practicle 8 Water Flashcards
(5 cards)
What it for
To analyse a sample of water for purity
Explain how to purify a sample of water by distillation
Potable water isn’t
The same as pure water as potable water contains dissolved solids and may not have a pH of 7 ( neutral)
To establishing water is pure
Check pH of water by placing a small amount of the water on a police of universal indicator paper. If it turns green the pH is 7
Use a balance to weigh an empty evaporating basin and record mass. Fill evaporating basin with water sample and place on a tripod and gauze
Use bunsen burner to gently Heat the water until its all evaporated .
Allow evaporating basin to cool and then weigh it again
If the water example contained any dissolved solids then the mass of the empty evaporating basin will have increased
If the water sample contained any dissolved solids it was not pure.
If the pH was neutral and the mass If basin didn’t increase then it was pure water
How to purify water by distillation equipment
Conical flask placed on top of gauze and tripod on top of a bunsen burner
Conical flask contains water sample
Top of Conical flask has a delivery tube in it which is pointed into a test tube
The test tube is sitting in a beaker containing ice and water
How to purify water by distillation method
Gently heat the water using bunsen burner so it boils gently
The water evaporates forming water vapour which travels along the collecting tube
When the water vapour enters the cold test tube it condenses back into liquid water.
This is distilled water which contains bo dissolved solids and has a pH of 7
Distilled water = pure water
