Solubility - Unit 1 Topic 10 Flashcards
Give 2 facts about water
It covers 70% of the earth
2/3 of your body is water
What is the physical test for water?
Freezes at 0°C. Boils at 100°C. Colourless.
What are 2 chemical tests for water?
Their colour changes?
Anhydrous copper sulphate
White -> Blue
Cobalt chloride paper
Blue -> Pink
3 steps of water purification
Sedimentation tank
Sand beads (filtration)
Chlorination
What does chlorination do?
Kills bacteria (typhoid & cholera)
What are 4 pollutants of our water supplies?
Fertilisers
Detergents
Thermal pollution
Lesticides
What is in fertilisers that are dangerous?
What do they lead to?
Nitrates and phosphates
Eutrophication
What is eutrophication?
When water plants grow and use up oxygen
What is the problem with thermal pollution?
Factories use water as a coolant. This is disposed of in lakes & rivers. The warm water increases the temp there and decreases oxygen levels. Oxygen gas is less soluble in hot water, kills the fish.
What is the problem with pesticides?
End up in water supplies. Designed to kill pests so are often poisonous to humans.
What is a saturated solution?
A solution which cannot dissolve any more solute
What is solubility?
A measure of how much of a solute dissolves in 100g of a solvent of a given temperature.
What 4 factors affect solubility?
Heat
Stirring
Volume of solvent
Amount of solute
Comment on the trend of solubility with increasing temperature for:
- gases
- solids
Solids = more soluble with increased temp Gases = less soluble with increased temp
What is the equation for solubility?
Solubility (g/100g of water) = mass of solute/mass of solvent x 100
