View source for GCSE Chemistry Required Practical: Purifying Water

==Key Stage 4==
{{#ev:youtube|https://www.youtube.com/watch?v=_UGHsbTEBvA}}
===Meaning===
Analysis and [[Pure|purification]] of [[water]] from different sources.

===Method===
A sample of rain water, sea water and bottled 'spring' water should be supplied.
====Testing the pH====
#Using a clean [[pipette]]s to add 2ml of a [[water]] [[sample]] to a [[Test Tube|test tube]] and label it.
#Add 2 drops of [[pH Indicator]] to the [[Test Tube|test tube]] and record the [[colour]] and [[pH]].
#Repeat steps 1 and 2 for each [[water]] [[sample]].
====Finding Solutes====
#[[Measure]] the [[mass]] of a [[Watch Glass]].
#Add 4ml of a [[water]] [[sample]] to the [[Watch Glass|watch glass]].
#Add 150ml of tap [[water]] to 250ml [[beaker]].
#Place the [[Watch Glass|watch glass]] on top of the [[beaker]].
#Heat the [[water]] in the [[beaker]] to [[boiling]] and keep [[boiling]] until all the [[water]] in the [[Watch Glass|watch glass]] has [[evaporating|evaporated]].
#Allow the [[water]] to cool and then [[observe]] the [[Watch Glass|watch glass]] for any remaining [[solute]]s.
#Measure the [[mass]] of the [[Watch Glass]] with [[solute]]s and subtract the [[mass]] of the [[Watch Glass|watch glass]] to find the [[mass]] of the [[solute]]s.
#Repeat the [[experiment]] for each [[water]] [[sample]] using a clean [[Watch Glass|watch glass]] each time.
====Purifying Water====
#Add 40ml of a [[water]] [[sample]] to a 100ml [[Conical Flask|conical flask]].
#Attach a [[bung]] and [[Delivery Tube|delivery tube]] to the top of the [[Conical Flask|conical flask]].
#Place a [[Test Tube]] in a cold [[Water Bath|water bath]].
#Heat the [[water]] [[sample]] in the [[Conical Flask|conical flask]] and arrange the [[Delivery Tube|delivery tube]] to pass the [[Water Vapour|water vapour]] into the cold [[Test Tube|test tube]] where it will [[condensing|condense]].
#Use the [[water]] collected to repeat tests for [[pH]] and finding [[solute]]s.
#Repeat 1-5 for each [[water]] [[sample]].