Unit 1 - Water, water everywhere (Physical Science extension)

Content

Solutions
Preparation of solutions
Crystallisation
Distillation
Measuring solution concentration
Solution concentration in g dm^-3
Dilution
Smoke and microparticulates (database)

Scheme of work

9PSU1.01 - Solutions

Mixtures are combinations of two or more substances that can be separated back to their original pure substances by physical means only.

Solutions are a special kind of mixture formed when a solid substance mixes so intimately with a liquid substance that the particles are no longer visible (although they may impart a colour to the solvent), nor do they settle to the bottom on standing.

Scientific terminology
Solute = the solid component of a solution
Solvent = the liquid component of a solution

Laboratory glassware: Beaker, conical flask, volumetric flask, pipette, burette, filter funnel, measuring cylinder. Why are they different shapes and sizes? - Discuss.

Measurement, SI units and other units

Conversion between length and volume units

1 cm³ is the volume occupied by a cube of 1cm length. It is NOT an SI unit, but it is a very handy size for use in a laboratory. 1m³ of water would have a mass of 1000 kg. Could you lift it up?

Study questions

1. Why do we have units of measurement?

2. What do the terms centimetre cubed and litre actually mean?

3. Draw a cube of size 10cm x 10cm x 10cm. What is its volume?

4. What is the mass of 1000cm³ of water?

5. What is the SI unit for mass?

Now test yourself

9PSU1.02 - Making solutions

Solutions are prepared by stirring a solute into a solvent (usually water). The process is known as dissolving or dissolution.

What variables are involved in making a solution?

Experiment: To investigate a factors that could affect the rate of solubility

Each group should brainstorm and choose one variable to plan the investigation. The plan must include the apparatus that is to be used (with dimensions) and an outline methodology.

9PSU1.03 - Crystallisation

9PSU1.04 - Distillation

9PSU1.05 - Solution concentration

The strength of a solution is known as its "concentration". It is a number that tells us the amount of solute dissolved in a solution. Notice that it is NOT the amount of solute dissolved in a solvent.

What is the difference?

9PSU1.06 - Solutions

9PSU1.07 - Solutions

9PSU1.08 - Solutions

9PSU1.09 - Solutions

9PSU1.10 - Solutions

9PSU1.11 - Solutions

9PSU1.12 - Solutions