Fill a burette with 50cm3 of soap solution, add 50cm3 of the first water sample into a flask and use the burette to add 1cm3 of soap solution to the
flask.
Put a bung in the flask and shake for 10 seconds. Repeat, adding more soap solution until a good lasting lather is formed (bubbles cover surface for at least 30 seconds)
Record how much soap was needed to create a lasting lather and repeat the process with other water samples.
Next, boil fresh samples of each type of water for 10 minutes and repeat the experiment.
When boiling the water for the experiement, water that was unboiled but needed little soap solution and needed the same amount boiled, will
be soft water, water that needed a lot of soap solution before and after will be hard. Water that needed lots of soap and a little soap after
boiled will be temporary