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There is a mistake in the solutions manual's answer to 16.42(a) in
the 13th and 14th ed. <br>
Even if you are using a different edition you should read this.<br>
<br>
The question is a T/F question, "All strong bases are salts of the
hydroxide ion".<br>
The answer in the solutions manual is True. That is not correct.<br>
<br>
As stated in Section 16.5 on strong bases, the most common strong
bases are the hydroxides<br>
of group 1A metals and the heavier group 2A metals, Ca(OH)2, Sr(OH)2
and Ba(OH)2.<br>
Mg(OH)2 is considered a "strong base" (strong electrolyte) since
whatever part of it which<br>
dissolves dissociates completely. However, since it's not very
soluble (and we'll see later<br>
the Mg^2+ ion is slightly acidic) it's not usually included with the
other group 2A bases.<br>
<br>
It then goes on to say at the end of that section strongly basic
solutions are also created by<br>
certain substances which react with water to form OH- and gives the
example of O^2-,<br>
the oxide ion. This is the conjugate base of OH-, if OH- acted as
an acid, which it doesn't,<br>
it's the strongest base that can exist in water. Thus the conjugate
base of OH-, assuming it<br>
acted as an acid, O^2-, is a stronger base than OH-.<br>
<br>
There were several others I mentioned in class. It's also discussed
in the following two<br>
links at the "Helpful Tidbits" link. I also list some other
examples of unusual strong bases<br>
in the first link.<br>
<br>
<a
href="https://www.asc.ohio-state.edu/zellmer.1/chem1250/faq/acid_base.txt"><b>Some
Aspects about Acids and Bases</b></a><br>
<br>
<a
href="https://www.asc.ohio-state.edu/zellmer.1/chem1250/faq/amphoterism.txt"><b>Further
Discussion on Acids and Bases</b></a><br>
<br>
<br>
Dr. Zellmer
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