Question

1 a) Write reactions for solubility and the equilibrium expression Ksp.

b) Solve for Ksp from molar solubility or molar solubility from Ksp.

c) Solve for solubility when a common ion is present.

d) Evaluate solubility changes according to pH changes.

e) Determine if a combination of solutions will produce a precipitate.

f) Determine minimum amount of a substance required to precipitate a substance.

Answer 1

a) Solubility products constant are use to describe saturated solution of ionic compound.

reaction ---- A_x B_y(s) ------->xA^y+ (aq) +yB^x+(aq) ................................(1)

equilibrium constant K _c = [A^y+]^x  *  [B^x+]^y

  equilibrium constant  is there refers to the product of the concentration of the ions that are presents in a saturated solution of ionic compound and given the solubility product constant

  

b) the molar solubility of substance is the number of mole present in solution.

calculate K_sp --- A_x B_y(s) ------->xA^y+ (aq) +yB^x+(aq) ..

K _sp = [A^y+]^x  *  [B^x+]^y

there x, y are both molar value and K_sp depends on molar stability

C)  Solve for solubility when a common ion is present.-------

i need took a simple solubility product calculate in common ion is present

example concentration of dissolved lead chloride

PbCl₂(s) --> Pb²⁺(aq) + 2 Cl^-(aq)

K_sp = [Pb²⁺][Cl^-]² ----------------(2)

Pb²⁺= S mole /dm^_3 and Cl^- = S mole /dm^_3

then K_sp =(S) *(2S)²= 4S³

  4S³ =K_sp

S³ = K_sp /4

d)  Evaluate solubility changes according to pH changes.-----

A_x B_y(s) ------->xA^y+ (aq) +yB^x+(aq)...............3 or zn(OH)_{2   $\leftrightharpoons$} ZN⁺  + 2OH^_

If increases PH value in solution by adding OH^_  ions then we can say that the position of equilibrium will be move to left

then solubility will decreases of       A_x B_y(s) or  zn(OH)₂

If decreases PH value in solution by adding H+   ions then OH^_ Ions remove then  we can say that the position of equilibrium will be move to right

e)When two aqueous solutions reaction together , they sometimes form solids in the solution. The solid is called as a precipitate. Precipitation reactions the Most precipitates are formed in a double-replacement reaction.

f)

Determine minimum amount of a substance required to precipitate a substance.----

M_i V_i =M_f V_f