Here's the reaction in the experiment, and assume you need x gram of CaCl2, y gram of Na2SO4, and z gram of NaCl produced
CaCl2 + Na2SO4 = CaSO4(s) + 2NaCl
111.0 142.0 136.1 2*58.44
x y 1.500 z
111.0 : 136.1 = x : 1.500, x = 1.223 g
142.0 : 136.1 = y : 1.500, y = 1.565 g
116.88 : 136.1 = z : 1.500, z = 1.288 g
1. Measure 1.223 g CaCl2, and put in a test tube, and add some water for it to completely dissolve.
2. Measure 1.565 g Na2SO4, and add to the test tube in step 1. You should see what precipitate forms (CaSO4).
3. Use a filter paper and filter the solution to a small beaker. CaSO4 will be on the filter paper. Dry it up and collect it (and measure it).
4. Heat the solution in the beaker slowly until all the water is gone. Wait for it to cool down to room temperature. Collect the NaCl from the beaker and measure it.
It's really difficult to get 100% yield. Here are some possible reasons. You could spill some in the process; not all CaSO4 is collected from the filter paper; not all CaSO4 is in solid state (some still in solution).
