Lead Chloride Solubility (K_sp)

MATERIALS

-          1L of 0.2M lead nitrate

-          1L of 0.2M sodium chloride

-          Two 250mL graduated cylinders

-          1L distilled water

-          1L of a saturated lead chloride solution

-          1L of 1M HCl

-          Large demonstration test tubes

-          2L waste beaker
 

PRESENTATION

1.      When K_sp is exceeded

a.   Mix about 100mL of 0.2M lead nitrate and 100mL of 0.2M sodium chloride in a large test tube

b.   A precipitate of lead chloride will form

-          The two concentrations (now 0.1M) will give an ion product greater than K_sp thus forming a precipitate

2.      When Q < K

a.       Make 100mL of 0.02M(1:10) lead nitrate from the 0.2M lead nitrate

b.      Make 100mL of 0.02M(1:10) sodium chloride from the 0.2M sodium chloride

c.       Mix the previous two solutions in a large test tube.

d.      No precipitate will form.

-          The two concentrations (now 0.01M) will give and ion product which is lower than K_sp resulting in no precipitate formation

3.      Common Ion Effect

a.       Pour 100mL of sat. lead chloride into a large test tube.

b.      Slowly pour 1M HCl into the test tube

c.       A precipitate will form

-          Because the lead chloride solution is saturated, the addition of more chloride ions will cause the lead chloride to precipitate.  The ion product will exceed K_sp

HAZARDS (MSDS Links)

Lead chloride: http://www.sciencelab.com/msds.php?msdsId=9924470

Sodium chloride:  http://www.sciencelab.com/msds.php?msdsId=9927593

Hydrochloric acid:  https://www.sciencelab.com/msds.php?msdsId=9924285

Lead Nitrate:  http://www.sciencelab.com/msds.php?msdsId=9924473