Chapter 8 salt is among the most popular chapter in SPM chemistry..
There's no doubt..You have to memorise the colour changes and experiments..
Alright..this experiment is important and should be memorised for the sake of exam.
(Preparation of Magnesium Sulphate) ->prepare a salt...
this salt is obtained from Acid + Metal Oxide..
MgO+H2SO4 -> MgSO4+H2O
1)50cm3of 1.0moldm-3 of sulphuric acid is measured and poured into a small beaker.
2)The sulphuric acid in the beaker is heated as shown in the diagram.(refer to book the diagram)
3)Magnesium Oxide is added in excess into the small beaker and stirred.
4)The hot mixture is filtered to remove excess magnesium oxide.
5)The filtrate is transfered into an evaporating dish and heated until1/3 of it's original volume.
6)The solution is allowed to cool and crystallize in the crucible.
(crystallization is a process where pure salt in crystal form is formed)
in short free from impurities..
7)The crystal obtained are dried by placing it between two filter papers.