Does anyone know how to prepare pure samples of magnesium sulphate, lithium chloride, or pottasium nitrate???
One method is by fractional crystalisation from a strong solution.Another is by zone refining fromthe molten state.The last is the most certain but most difficult of the two methods.If the raw material is really manky and you want it 99.999.. pure start with filtering a solution(made with distilled water).then use a couple of stages of fractional recrystalisation.(which means make a hot strong solution and allow to cool slowly)pure crystals will form as it cools and if possible remove them.If not possible,then take one salt crystal and tie it to a piece of thread,then reheat the solution and after its cooled a little(just above the temperature at which you took the crystal)dangle the crystal in the solution and leave to coolwhen you have a fair sized crystal take it from the solution then through away the liquid because thats where most of the impurities remain..Obviously you need to use some kind of support to hold the crystal in the solution while it grows because the slower the cool
