[kusumoto]

We are doing a project in school in which we must make 2.0 grams of CaSO₄ in a double displacement reaction. Our reaction is FeSO₄+CaCl₂=FeCl₂+CaSO₄

We have decided that we need 2.23g FeSO₄ and 1.63g CaCl₂

Our real problem is that we need to make a procedure without being able to actually test it first. This is what we have so far, not really sure if it will work.



Materials
1 100ml Beaker
2 Erlenmeir(spelling?) Flasks
1 50ml graduated cylinder
1.63g CaCl₂
2.23g FeSO₄
Filter Paper
Glass Funnel

Procedure

1.) Dissolve 1.63g CaCl₂ in 50ml of water in a flask.
2.) Dissolve 2.23g FeSO₄in a separate beaker of 50ml of water.
3.) Pour both solutions into another beaker and mix.
4.) Filter the solution to retrieve the CaSO₄

This is the equation we have.

1.63g CaCl₂+2.23gFeSO₄=2.00gCaSO₄=1.93gFeCl₂

We need as close to 2.0g CaSo₄ as possible.

We have no way of testing if this will work. We aren't sure how to mix it, or what will be filtered out, whether it is FeCl₂ or CaSO₄.

We would like help on our procedure as we can't actually test it. Thanks in advance.

[Borek]

CaSO₄ is weakly soluble - saturated solution is about 0.005M. To get best results try to use minimal amount of water and use excess of one of the reagents.

[Alberto_Kravina]

We need as close to 2.0g CaSo4 as possible.

To precipitate CaSO₄ form a satured solution just add Ethanol.
I would make it like this: Precipitate the sulfate in aqueous solution, after that add Ethanol.
In my opinion the volumina of water that you use are a bit too big...  

[americanstrat4]

Wouldn't it be logical to have the molarity of both solutions be the same because the rxn is 1:1?  I think that might help.  Unless I'm wrong...  Just a thought.  Unless you are given specifically the amount of compound that you have listed.

[Borek]

Wouldn't it be logical to have the molarity of both solutions be the same because the rxn is 1:1?

Doesn't matter, although may make calculations easier. However, it doesn't make sense to fight for identical concentrations of solutions if all they are interested in is a mass of product - they should concentrate on precise weighting of a limiting reagent. This way they will not loose time for unnecesary operations - and the excess reagent can be wieghted only approximately.

[americanstrat4]

Yeah!  You're right.  More calculations just gives you more source for math error as well.