Gravimetric Analysis Practical
Aim:
To undertake a gravimetric analysis in the separation of a sand, salt and water mixture.
Risk Assessment
Risk
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Electrocution
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Cuts from broken glass
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Burns from hot equipment
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Mitigation
Do not have water near electronic
balance.
Do not clean up any glass breakages.
Leave the area and inform the teacher.
Allow equipment to cool before putting
it away.
Equipment:
Sand and salt mixture, deionised water, filter paper, filter funnel, evaporating dish, Bunsen, tripod,
pipe clay triangle, beaker, wash bottle, retort ring
Method:
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Collect all the equipment.
Measure and record the mass of a 50mL beaker
Add a small quantity of the sand and salt mix to the beaker
Cover the sand and salt mix with deionised water
Measure and record the mass of the beaker and the mixture
Set up the filtration apparatus
Measure and record the mass of the filter paper
Measure and record the mass of the evaporating basin.
Filter the mixture with the filtrate going into the evaporating basin
Rinse the beaker with a small amount of deionised water
Remove the filter paper and place on the window sill to dry
Set up the Bunsen and tripod and evaporate the water from the solution in the evaporating
basin. Extreme caution is required as the salt nears dryness.
Allow the evaporating basin to cool then measure and record the mass of the evaporating
basin plus the salt.
When the sand has dried measure and record the mass of the filter paper and sand
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Results
Mass of Sand + filter paper =
Mass of filter paper =
Mass of Sand =
(g)
Mass of evaporating dish + salt =
Mass of evaporating dish =
Mass of salt =
Calculations
% composition of sand =
% composition of salt =
(g)
mass of sand
x 100 % m/m
Total mass of mixture
mass of salt
x 100 % m/m
Total mass of mixture
% composition of water = 100 – (% composition of salt) – (% composition of sand) = % m/m
Discussion
The gravimetric analysis identified that the mixture contained x% of salt, y% of sand and z% water.
Possible errors include:
Conclusion
The experiment demonstrated the procedure for conducting a gravimetric analysis.