Question

Describe how to write the Ksp.

Answer 1

b2+ + 2 NO3- + 2 Na+ + 2 I- >> PbI2 (s) + 2 Na+ + 2 NO3-  

net ionic

Pb2+ + 2 I- >> PbI2  

Ksp = [Pb2+] [I-]^2  

Ksp = 7.1 x 10^-9  

molar solubility

let x = mol/L of Pb2+ that dissolve . This will give x mol/L Pb2+ and 2x mol/L I-  

7.1 x 10^-9 = (x) (2x)^2 = 4x^3  

molar solubility = 0.0012 M

~~thanks to google research~~

Answer 2

Answer:

Well, for a start Ksp=Ksolubility product, and we use an equilibrium expression. 

Explanation:

For the sparingly soluble salt, MX, we write the equation that represents its dissolution:

MX(s)H2O⇌M++X−

Ksp=[M+][X−][MX(s)], but MX(s) as A SOLID cannot express a concentration, and thus the expression simplifies to...

Ksp=[M+][X−]

Usually standard conditions are specified, because a hot solution can generally hold more solute than a cold one.

For salts of the form MX2, Ksp=[M2+][X−]2. Ksp
have been measured for a host of insoluble, and semi-soluble ionic salts.