Understand the appropriate methods to be used when carrying out qualitative analysis tests: • to treat all unknown materials with caution • to use an appropriate quantity of the material under test • to add only the specified amount to work safely, • to use a test-tube holder when heating a solid in a hard-glass test tube • to record all observations, even when this is ‘no change' or ‘remains a colourless solution’ • to use excess alkali where a precipitate is produced on addition of NaOH(aq) or NH3 (aq) to determine its solubility or identify a gas whose formation is shown by effervescence.