Part 1) For each of the salts on the left, match the salts on the right that can
ID: 552186 • Letter: P
Question
Part 1) For each of the salts on the left, match the salts on the right that can be compared directly, using Ksp values, to estimate solubilities. (If more than one salt on the right can be directly compared, include all the relevant salts by writing your answer as a string of characters without punctuation, e.g, ABC.)
1. magnesium hydroxide A. CuCO3
2. lead carbonate B. Pb(OH)2
C. Mn(OH)2
D. CaS
***1 & 2 COULD HAVE MULTIPLE ANSWERS***
Part 2) Write the expression for K in terms of the solubility, s, for each salt, when dissolved in water.
magnesium hydroxide: ksp =
lead carbonate : ksp =
Note: Multiply out any number and put it first in the Ksp expression. Combine all exponents for s.
Explanation / Answer
1. magnesium hydroxide can be compared with Pb(OH)2, Mn(OH)2 (BC)
2. lead carbonate can be compared with CuCO3, CaS (AD) (note: similar ion composition will give similar molar solubilities eg: monovalent cation and bivalent anion etc.)
Ksp of Mg (OH)2 = [Mg2+] [OH-]2
Ksp of PbCO3 = [Pb2+] [CO32-]