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1) Why is it not very accurate to describe an aqueous metal ion as M+(aq)? Choose from:

-because the metal ion is actually bound to several water molecules in a complex ion
-because formation constants of complex ions tend to be very large, which makes the aqueous ions difficult to generate in solution
-because a metal ion, M+, is actually a Lewis acid, which is not reflected in the notation
-because the notation ignores what else is present around the ion

2) Lead thiocyanate, Pb(SCN) 2 , has a K sp value of 2.00×10 −5 .Calculate the molar solubility of lead thiocyanate in 0.600M KSCN . Express your answer with the appropriate units.

3) Calculate the pH of the solution made by adding 0.50mol of HOBr and 0.30 mol of KOBr to 1.00 L of water. The value of K a for HOBr is 2.0×10 −9 .Express your answer numerically using two decimal places.

4) Buffer capacity depends on two quantities. What are they? Choose from:

-an equal number of conjugate acid and base molecules, and a high concentration of each
-how close the buffer is to having a 10:1 ratio of the buffer components, and having a high concentration of the components
-a high concentration of conjugate acid molecules in solution and the pH of the solution
-the range of pH values over which the solution can act as a buffer, and an equal ratio of conjugate acid to conjugate base

5) Calculate the ratio of CH 3 NH 2 to CH 3 NH 3 Cl required to create a buffer with pH = 10.14. Express your answer using two significant figures.

Solution Preview

Hi there,

Thanks for letting me work on your post. Here is my explanation:

1. The first one is the right choice.

2. based on the definition of ksp, ...

Solution Summary

The expert determines why it is not very accurate to describe an aqueous metal ion as M+(aq). Complex ions are analyzed.