Question: Lead(II) bromide, PbBr 2 , is a slightly soluble saltwith a K SP value of6.6 x 10 -6 . The equation for itsdissociation in water

Lead(II) bromide, PbBr2, is a slightly soluble saltwith a KSP value of6.6 x 10-6.  The equation for itsdissociation in water is

PbBr2(s)   <---------->  Pb2+(aq)   +  2Br-(aq)

What is the molar solubility of PbCl2 in distilledwater? I KNOW THE ANSWER IS 1.2 x 10 ^-2 mol/L

but I don\'t understand this part:
In the previous problem, you calculated the molar solubility ofPbBr2 in distilled water.  Now consider themolar solubility of PbBr2 in a 3.55 M NaBrsolution.  Sodium bromide is a freely soluble salt, andcompletely dissociates into its ions when dissolved in water:

NaBr(s)   ==========>  Na+(aq)   +  Br-(aq)

Therefore, a 3.55 M NaBr solution is 3.55 M inNa+ and 3.55 M in Br-.  Whenthe PbBr2 is dissolved in this solution, itestablishes its usual equilibrium:

PbBr2(s)   <---------->  Pb2+(aq)   +  2Br-(aq)     KSP = 6.6 x 10-6

But in the 3.55 M NaBr solution, theBr- concentration will be 3.55 M,even before thePbBr2 dissociates.  TheBr- formed in the dissociation ofPbBr2 will be in addition tothat already present.

What is the molar solubility of PbBr2 in the3.55 M NaBr solution?

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

we need to consider the common ion effect When PbBr2 is dissolved in a solution containing a h... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Chemistry Questions!