precipitation analysis considering the formation of solid from solution. q vs. ksp ion analysis
TRANSCRIPT
Precipitation Analysis
Considering the formation of solid from solution.Q vs. Ksp
Ion Analysis
How to predict whether a precipitate will form when two solutions are mixed?
• Investigate Qsp vs. Ksp at initial concentrations
Q = Ksp “Saturated” solution occurs. No changes.
Q > Ksp Precipitates will form until saturated. Equilibrium shifts left.
Q < Ksp NO precipitate forms. Solid dissolves. Equilibrium shifts right.
Sample Exercise p. 734
• Predict whether precipitate will form?
Q > Ksp
PPT will form!
Selective Precipitation
• Mixtures of metals in solutions are separated using a technique called selective precipitation.
• Using a reagent whose anion forms a precipitate with only one or a few of the metals in the mixture.
• Sulfide salts (sulfide ion) is often used!
Sample Exercise 17.16 p.735
Qualitative Analysis of Cations• Separating mixtures into five major categories
based on solubility.
#1. Insoluble Chlorides#2. Insoluble sulfides in Acids.#3. Insoluble sulfides in Bases. #4. Insoluble carbonates. #5. Alkali metals and ammonium ions.
