Concentration How to make a standard solution of a known concentration. C Calculate the concentration of a solution. B Re-arrange equation to calculate mass/volume when given concentration and volume/mass. A

Starter Use white boards to answer recap quiz.

Any analytical test must be carried out on a solution. You only test a sample (small bit of it). Dissolve the sample in a solution. Aqueous means water Non aqueous any thing but water. E.g. ethanol Must follow a standard procedure. Standard procedures are the safest, most effective and most accurate. A standard procedure is the same in a company, nationally and internationally. Standard procedures are always reliable Standard proceedures for collection, storgae and testing.

Concentration = mass of solute ÷ volume of solvent (g/dm3) (g) (dm3) x

Complete activity sheet

Making a standard solution (This has a known concentration) Work out how many g of solute you need by using equation. Weigh out mass of solute. Add a small amount of distilled water and stir. Tip in to a volumetric flask, use a funnel Rinse the beaker, rod and funnel and add to flask. Top up to correct volume, ensure meniscus reaches the line. Stopper and mix a few times. Check meniscus.

Make a standard solution Make 250cm3 of 314g/dm3 of NaCl To answer : Why carry out steps 3-8?

Plenary Rate learning 1-4 (1 poor, 4 excellent) Rate activities (as above) Write 1 thing you really understand Write 1 thing you still do not understand