Solubility Thallous Chloride

amy

1. The problem statement, all variables and given/known data
6.5g of thallous chloride is added to 750ml of water at room temperature to determine Ksp.  The solution is stirred from time to time over a 4h period.  Some thallous chloride does not dissolve and the solution is declared saturated.  A 400ml sample of the solution is decanted off and evaporated to dryness.  The weight of thallous chloride that remains is 1.20g.
a) What is the solubility of thallous chloride?
b) What is Ksp for thallous sulfate?2. Relevant equations

TlCl -gt; Tl +Cl
Ksp=[Tl][Cl]

3. The attempt at a solution

6.5g=0.027 mol
c=0.036 i dont know what else to if no ksp is given something to get me started would be helpful.thnks  

    Where is thallous sulfate mentioned in the problem ( part b ) ?

So the solubility of thallous chloride is 1.20g / 400 mL of water without respect to volume change from dissolution of the thallous chloride.  Express this in the appropriate units.  

    oh in part b it is a typo. so 6.5g (750ml) is irrelevant?  

                                   Originally Posted by the.flea                   oh in part b it is a typo. so 6.5g (750ml) is irrelevant?                  
No it doesn't matter ; now simply convert the saturated amount of thallous chloride into moles and then use the molecular formula to fill in the values for the Ksp equation to solve for Ksp.  Show your steps.  

    m=1.2g                         TlCl--gt;Tl + Cl
mm=239.83g                    1  :   1   :  1
n=0.005mol
c=n/v
c=0.0125mol/L
solubility = c

Ksp=[0.0125][0.0125]
=1.56E-4is this correct????  

   OK.

Borek
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    Yeah your steps are good.