A LEVEL CHEMISTRY - PRACTICALS

Measuring Mass:

Using the Electronic Balance:

• Before measuring any mass, press the “tare” button to make sure that the intial reading is zero.
• Make sure that the electronic balance is clean with no residues on it. Blow lightly if you feel there are any.
• The precision of the electronic balance is up to 2 decimal places e.g. 13.45 g.
• Units: Electronic balance measure in grams, so always write units (“g”, “/g”, or “grams”) beside every reading.
• All recordings should be made in a single table. Otherwise your 1 Mark will be on stake.
• As already stated, the headings and their units have separate marks. Write mass/g or mass (g) but m/g or mass g are not allowed. Full name of quantity must be used.

Below is a table that may be used for recording Masses:

	Exp. 1	Exp. 2
Mass of empty test-tube / g
Mass of empty test-tube + Sample X / g
Mass of test-tube + residual Sample X / g
Mass of sample X used / g

Measuring Temperature:

There’re only a few tips relating to this measurement. First, always stir the mixture before recording the temperature. Second,  when measuring temperature, make sure that the thermometer is not taken out from the solution.