Solutions Flashcards
What is a solvent?
A solvent is a substance that dissolves other materials to form a solution
What is a solution?
A mixture of a solute and solvent
What is a suspension?
When a solid added to water becomes scattered throughout the liquid and looks cloudy
What is a dilute solution?
A solution with a small amount of solute and a large amount of solvent
What is a concentrated solution?
A large amount of solute and a small amount of solvent
How do you grow crystals of copper sulfate?
- Grind up a sample of copper sulfate using a pestle and mortar
- Add the substance to 100 cm3 of water until the solute no longer dissolves but settles at the bottom of the beaker. Note the water temperature
- Heat the water to 60©
- Pour half the solution into a warm evaporating basin to cool
- Crystals are formed
What is a saturated solution?
A saturated solution is one that contains as much dissolved solute as possible at a given temperature
How is solubility measured?
The solubility of a substance is its mass (in grams) that will dissolve in 100 grams of solvent at a fixed temperature
How do you investigate the effect of temperature on solubility?
- Grind up a substance (copper sulfate) with a pestle and mortar
- Weigh out 100g of copper sulfate
- Place 100 cm3 of water in a beaker and heat the water to about 30©.
- Measure the exact temperature with a thermometer
- Add some copper sulfate and stir after each addition until no more will dissolve
- Weigh the amount of copper sulfate not added and by subtraction calculate the amount of copper sulfate that has dissolved
- Repeat at different temperatures to form a solubility curve
What is a solubility curve?
A graph showing how the solubility of a substance varies with temperature
What is crystallisation?
The formation of the crystals when a hot saturated solution is cooled or when the solvent is allowed to evaporate from the solution
