Cliffs AP Chemistry, 3rd Edition

7. What was the molar concentration of Pb2+in the solution at equilibrium?
   
   
   • 3
     .
     ..
     L
   
   
   
   

mol Pb M

0 010

37 10# -^52 =37 10# -

8. Determine Ksp

Ksp= [Pb2+] [I–]^2 = (3.7 × 10 –3M) (1.4 × 10 –3M)^2 = 7.3 × 10 –9M^3

9. The published value of Kspat 25°C for PbI 2 is 7.1 × 10 –9. Determine the percent error.

% %%

.

..

exp

exp

error

obs

100 100

71 10

73 10 71 10

9

99

#

#

##

#

• =
  
  
  • = -
  
  
  
  

_i--

= 2.8 %

Laboratory Experiments