Sciencemadness Discussion Board

Help urgently needed

FluffyD - 18-11-2003 at 07:22

HELP ME PLEASE!!!!!
How can I increase the percentage yield of BaSO4 when made from Barium Chloride and Magnesium Sulphate. I have tried looking all over the place and dont know what else I can do. I have an assignment due in soon so any help would be sooooo greatly appreciated.

I am a fish - 18-11-2003 at 08:49

1. Use a proper title. "Synthesis of Barium Sulphate" is infinitely more informative than your chosen title.

2. Your question is ambiguous. By "increase the percentage yield", do you mean maximise the ratio of BaSO4 out to BaCl2 in, or do you mean to calculate the stoichiometric ratio (which seems more likely)?

3. You are unlikely to find online help for this particular problem (as it is just one example of a vast class of reactions). Search for 'Precipitation Reactions'.

4. Deduce the molar ratio in which the BaCl2 and MgSO4 react. By multiplying by the molar masses of the reagents, the mass ratios in which they react can be obtained.

DDTea - 18-11-2003 at 11:27

You might want to try heating the solutions, so that you have a more complete dissolution of the reactants. After the reaction is finished, try cooling it down, so as to maximize the amount of product that precipitates out.

vulture - 18-11-2003 at 12:09

Add an excess of magnesium sulfate.
This will increase the precipitation of the bariumsulfate, because the max solubility of the sulfate will be reached much faster.

unionised - 18-11-2003 at 15:19

Add an excess of barium chloride as this will reduce the solubility of the product. Use 50% alcohol as the solvent because the solubillity of barium sulphate is (marginally) lower in this solvent than in water.
The question wasn't specified adequately in the first place.
BaSO4 is so poorly soluble in water that the reaction will go virtually to completeion anyway.