Water Flashcards
(31 cards)
Water cycle
Sun causes evaporation, water vapour is acrried up, warm air rises. Cools and condenses due to atmosphere, when condensed droplets get too big they fall as rain, water runs back to the sea and comes into contact with rocks along the way so at different places the water will dissolve different minerals.
Water dissolves most…
Ionic compounds
What dissolves in water?
Salts of sodium, potassium and ammonium
All nitrates
Chlorides except Sliver and lead.
Sulfates except barium and lead, calcium is only slightly soluble.
What causes acid rain?
Sulfur dioxide
What causes acid rain?
Sulfur dioxide
What is the solubility of a substance?
The number of grams of the solute (usually solid) that will dissolve in 100g of the solvent (the liquid) at a particular temperature.
What is the solubility of a substance?
The number of grams of the solute (usually solid) that will dissolve in 100g of the solvent (the liquid) at a particular temperature.
The solubility of a solid usually increases with…
Temperature
The solubility of a solid usually increases with…
Temperature
What is a saturated solution?
Is one that cannot hold any more solid at that temperature.
What is a saturated solution?
Is one that cannot hold any more solid at that temperature.
What makes gases dissolve more?
A higher pressure above it.
What makes gases dissolve more?
A higher pressure above it.
Gases become less soluble as the…
Temperature of the solvent increases which it the opposite of solids.
Gases become less soluble as the…
Temperature of the solvent increases which it the opposite of solids.
Hard water is caused by…
Calcium and magnesium ions.
Hard water is caused by…
Calcium and magnesium ions.
What rocks cause hard water?
Limestone, chalk and gypsum.
What rocks cause hard water?
Limestone, chalk and gypsum.
From what reaction can calcium and magnesium salts come from?
When carbon dioxide from the air dissolves in rainwater, you get carbonic acid.
From what reaction can calcium and magnesium salts come from?
When carbon dioxide from the air dissolves in rainwater, you get carbonic acid.
Advantages of hard water…
Ca2+ ions are good for healthy teeth and bones. Scale forms a protective coating inside pipes and stops poisonous mortals ions, pb2+ and Cu2+ getting into drinking water.
Advantages of hard water…
Ca2+ ions are good for healthy teeth and bones. Scale forms a protective coating inside pipes and stops poisonous mortals ions, pb2+ and Cu2+ getting into drinking water.
How can you remove hardness?
Add sodium carbonate, carbonate ions join onto the magnesium or calcium ions to make an insoluble precipitate.
Ion exchange columns, which have lots of sodium ions or hydrogen ions and exchange them for calcium or magnesium ions in the water as it runs through.
