Question

5. Solubility, while it can be expressed in terms of solution chemistry and solubility products, it can also easily be described in terms of Le Chatliers principle.

Consider Group II Qualitative analysis, the initial step is controlled by the following equilibrium:

MS(s) ⇄ M+2(aq) + S-2(aq) Ksp = small number

What is the practical result of adding a concentrated Ammonium Sulfide ( (NH4)2S ) to the saturated solution? (described in terms of M and MS)

6 How would you rate the acidity or basicity of S-2?   Once you identify the nature of S-2 write the appropriate acid or base dissociation reaction and the correct Ka or Kb statement

7. Using the information in question 5 and 6 describe the result of adding nitric acid in Step 6 in the qual scheme: Using the reaction you wrote in 6, discuss the effect on the S-2 concentration upon addition of the strong acid in an S-2 solution and how would lowering the pH affect the M+2 conc and the overall MS solubility?

Answer 1

let o 22 44

sr 5/tof圢.ruet fau++-give H2S