Question

What is the solubility of BaSO4
in a solution of
0.250 M Na2
SO4
? The Ksp of BaSO4
is 8.7 x 10-11.

Answer 1

BaSO4 has a certain solubility by itself; with Na2SO4 the solubility is decreased due to the common ion effect. The common ion is the sulfate ion. You have two equilibria.
........Na2SO4 ==> 2Na+ + [SO4]^2-
I.......0.250.......0......0
C......-0.250.....0.50...0.250
E........0........0.50...0.250

.......BaSO4==> Ba^2+ + [SO4]^2-
I......solid....0.........0
C......solid....x.........x
E......solid....x.........x

Ksp = (Ba^2+)[(SO4)]^2-
Ksp you know.
(Ba^2+) is x
[(SO4)]^2- is x from the BaSO4 and 0.250 from the Na2SO4 so total is x+0.250
Substitute and solve for x.

Answer 2

1.calculate the pH of a 0.050 M HCl solution.Since HCl is a strong acid, it dissociates completely.

2.What is the pH of a 0.0026 M NaOH solution.

3.Distinguish between table sugar dissolving in water and
table salt dissolving in water.

4.. What type of intermolecular forces of attraction must be
overcome to melt each of the following solids?
(a) ice, H2O(s) (b) iodine, I2(s)

5.State the principle on which the VSEPR theory is based.

6.Use electronegativity values and VSEPR theory to determine
whether carbon tetrachloride, CCl4
, and ammonia,
NH4
, are polar or nonpolar molecules.