[gt5hz]

Purpose: To determine the % by mass of barium chloride and the % by mass of sodium chloride in sand.

Materials:
electronic balance
retort stand
ring clamp
filter funnel
fiolter paper (to fit filter tunnel)
glass rod
3 beaklers (250mL)
drying oven
wash bottle and distilled water
sample of sand containing BaCl2 and NaCl
solid sodium sulphate Na2SO4

The reaction to determine the % masses is as follows:

BaCl2 (aq) + Na2SO4 (aq) --> BaSO4 (s) + 2NaCl (aq)

The objective is to create a procedure to achieve the purpose.

I've currently devised something to this effect.

1. Mass the contaminated sand in an empty massed beaker.
2. Filter out the sand portion using the filter paper and mass the sand. Determine the mass of the sand using these first 2 steps.
3. Mass the end result (the combination of BaCl2 and NaCl).

This is where I'm stuck. With the allowed materials, how would I distinguish between BaCl2 and NaCl?

[lancenti]

You haven't actually used your little equation to precipitate out Barium Ions as BaSO₄ from solution. Maybe once you do that, you can find out how many moles of Barium there are and work out how much BaCl₂ there was originally.

For Sodium, you may want to use Chlorine instead - I know AgCl will precipitate out. Maybe that would be of use to you.

[eunChae]

First, mass the contaminated sand and put a certain mass/volume of water onto it. Sand will be precipitated and BaCl2 and NaCl will be dissolved. Thus, you can separate sand using filter paper and eventually you will have a solution containing BaCl2 and NaCl. After that you have many ways to estimate how many grams of BaCl2 and NaCl mixture.(for instance you can dry the mixture out and mass it,note it somewhere) Then, again dissolve this mixture in a certain mass of water and add a certain mass/mole of Na2SO4.After the reaction you showed in your post, BaSO4 will precipitate. Filter it and mass it. Depending upon stoichiometry rules, you can easily estimate how many moles of BaCl2 is formed because you know the number of moles of BaSO4. Now you know the mass of BaCl2 and therefore subtracting it from the mass of the mixture of BaCl2+NaCl at the beginning, you can easily estimate the mass of NaCl.   

[gt5hz]

First, mass the contaminated sand and put a certain mass/volume of water onto it. Sand will be precipitated and BaCl2 and NaCl will be dissolved. Thus, you can separate sand using filter paper and eventually you will have a solution containing BaCl2 and NaCl. After that you have many ways to estimate how many grams of BaCl2 and NaCl mixture.(for instance you can dry the mixture out and mass it,note it somewhere) Then, again dissolve this mixture in a certain mass of water and add a certain mass/mole of Na2SO4.After the reaction you showed in your post, BaSO4 will precipitate. Filter it and mass it. Depending upon stoichiometry rules, you can easily estimate how many moles of BaCl2 is formed because you know the number of moles of BaSO4. Now you know the mass of BaCl2 and therefore subtracting it from the mass of the mixture of BaCl2+NaCl at the beginning, you can easily estimate the mass of NaCl.   

Wouldn't using stoichiometric calculations for the formula result in the mass of the aqueous barium chloride and not the mass of it if it was solid?

[lancenti]

BaCl₂ (aq) and BaCl₂ (s) weigh the same, unless there's water like CuSO₄ anhydrous and CuSO₄.6H₂O

[eunChae]

as lancenti said, both weigh same, since we know BaCl2 is not aquocomplex.

[Borek]

CuSO₄.6H₂O

CuSO₄.5H₂O 

[lancenti]

I was under the impression that both existed.

Well, 5 it is then.