Water & Solubility Flashcards
Define a solution?
The mixture of a solute and solvent that doesn’t separate out.
Define a solute?
The substance being dissolved.
Define a solvent?
The liquid it’s dissolving into.
Define a saturated solution?
A solution where the maximum amount of solute has been dissolved – no more solute will dissolve in the solution.
What is solubility?
The ability of a substance to dissolve in a solvent.
Measured in: grams of solute/ hundred grams of solvent.
Investigate the solubility of a solute in the water at a specific temperature?
Make a saturated solution of the solid in the boiling tube.
Stir the solution and place the boiling tube in a water bath at a temperature for five minutes.
Pour some of the solution into the pre-evaporating basin and reweigh the basin and its contents.
Hate the evaporating basin until all the water has been evaporated and reweigh the basin and contents.
This solubility can be found by dividing the mass of solid left in the basin by the mass of water removed during the evaporation.
How can we calculate solubility?
Mass of solid
——————— * 100
Mass of water removed
Describe the solubility of sodium/potassium/ammonium?
Sodium - soluble.
Potassium - soluble.
Ammonium - soluble.
Describe the solubility of nitrates?
Nitrates – soluble.
Describe the solubility of chlorides?
Chlorides – soluble except silver and lead.
Describe the solubility of sulphates?
Sulphates – soluble, except barium/calcium/lead.
Describe the solubility of carbonates?
Carbonates – insoluble except sodium/potassium/ammonium.
Describe the solubility of hydroxides?
Hydroxides – insoluble except sodium/potassium/calcium.
Describe a test for the presence of water using anhydrous copper (II) sulfate?
Add anhydrous copper (II) sulphate and see if the white powder turns blue – water present.
Describe a physical test to show if the water is pure?
If the boiling point isn’t 100°C, or the freezing point isn’t 0° Celsius – sample isn’t pure.
