Practical 11 - Graviametric Analyis Flashcards
Method for using gravimetric analysis to identify an unknown metal chloride
Accurately weigh around 0.3G of the unknown chloride and transfer to a 250cm^4 beaker
Dissolve the sample in approximately 100cm^3 of deionised water and add 3cm^3 of 6moldm^3 HNO3
Slowly add 20cm£ of AgNO3 solution until silver chloride is seen to coagulate, then add a further 5cm^3 of AgNO3
Heat the beaker carefully without allowing the solution to boil for 10 minutes
Leave the solution to cool for at least 2 hours
Accurately weigh a filter paper and place in a filter funnel
Decant the liquid from the beaker into the funnel
Wash the precipitate in the beaker with 3cm^3 of wash solution
Transfer all the precipitate to the filter funnel and wash with 20cm^3 of wash solution
Test the used wash solution by adding 3 drops of HCl solution. If a precipitate forms (indicating the presence of Ag+ ions), wash with a further 10cm^3 and re-test
Dry the precipitate in the filter paper at 150 degree Celsius until constant mass is attained
