Solid NaI is slowly added to a soln that is 0.010M in Cu+ and 0.010M in Ag+.
a. Which compound will begin to precipitate first?
b. Calculate [Ag+] when CuI just begins to precipitate/
c. What percent of Ag+ remains in solution at this point?
a. Compare Ksp for CuI with Ksp for AgI. obviously, the salt with the smaller Ksp will ppt first.
b.
(Ag^+)(I^-)...Ksp for AgI
----------- = ----------- = about 7E-5
(Cu^+)(I^-)...Ksp for CuI
The value will depned upon the Ksp values you used so the answer should be close to 7E-5 but it may differ somewhat. Then you rearrange the equation to give (Ag^+)= 7E-5(0.01) = ??
c. (amount Ag remaining/original amount)*100 = ??
Can you just post the full answer for me
To determine which compound will begin to precipitate first, we need to compare the solubility products (Ksp) of the potential precipitates. The compound with the smaller Ksp will precipitate first.
a. To determine which compound will precipitate first, we compare the Ksp values of CuI and AgI. The Ksp for CuI is 5.3 x 10^-12, and the Ksp for AgI is 8.3 x 10^-17. Since CuI has a higher Ksp value, it is more soluble compared to AgI. Therefore, AgI will begin to precipitate first.
b. To calculate the concentration of Ag+ when CuI just begins to precipitate, we need to equate the product of the ion concentrations to the Ksp of CuI.
CuI (s) ⇌ Cu+ (aq) + I- (aq)
At this point, the concentration of I- will be equal to that of Cu+ since they are present in a 1:1 ratio.
Ksp = [Cu+][I-]
5.3 x 10^-12 = (0.010 - [Ag+])(0.010 - [Ag+])
Simplifying the equation, we have:
5.3 x 10^-12 = (0.010 - x)(0.010 - x)
Expanding and rearranging the equation:
5.3 x 10^-12 = 0.010^2 - 0.020x + x^2
The value of x, representing [Ag+], can be solved by using the quadratic formula or approximated by inspection. The approximate solution for [Ag+] is 1.0 x 10^-8 M when CuI just begins to precipitate.
c. To calculate the percentage of Ag+ remaining in solution at this point, we can compare the initial concentration of Ag+ and the concentration at the point of precipitation.
The initial concentration of Ag+ was given as 0.010 M.
The concentration of Ag+ when CuI just begins to precipitate is approximately 1.0 x 10^-8 M.
The percentage of Ag+ remaining in solution can be calculated as:
(1.0 x 10^-8 M / 0.010 M) x 100 = 0.0001 %
Approximately 0.0001% of Ag+ remains in solution at the point when CuI just begins to precipitate.