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<big><font size="2"><big>The publisher's solution to 14.88 in the
11th edition is wrong. This<br>
is EOC exercise 14.102 in the 12th ed. and 14.96 in the 13th
ed.<br>
(although the solutions' manual has the correct answer for
these ed.).<br>
<br>
This question deals with half-lifes and how they depend on
conc.<br>
(do they vary with conc and what happens to consecutive
half-lifes<br>
as the reaction proceeds). Remember, the half-life for a
1st-order<br>
reaction doesn't depend on conc. so consecutive half-lifes are
constant.<br>
Reactions which are other orders (zero, 2nd, etc.) have
half-lifes which<br>
depend on conc. and consecutive half-lifes change as the
reaction<br>
proceeds.<br>
<br>
For a zero-order reaction the half-life is proportional to the
initial conc.<br>
([A]o/2k) and consecutive half-lifes decrease (prove each one
is cut in<br>
half, e.g. 10 s, 5 s, 2.5 s, etc.).<br>
<br>
For a first-order </big></font></big><big><font size="2"><big>reaction
the half-life </big></font></big><big><font size="2"><big> is
constant and doesn't depend<br>
on conc (0.693/k) and consecutive half-lifes are constant (10
s, 10 s,<br>
etc.).<br>
<br>
For a second-order </big></font></big><big><font size="2"><big><big><font
size="2"><big>reaction the half-life is inversely
proportional to the<br>
initial conc. (1/k</big></font></big></big></font></big><big><font
size="2"><big><big><font size="2"><big><big><font size="2"><big><big><font
size="2"><big>[A]o</big></font></big></big></font></big>)
and consecutive half-lifes increase (prove each<br>
one doubles, e.g. 10 s, 20 s, 40 s, etc.).<br>
<br>
</big></font></big>If you find other mistakes please let
me know. Make sure you tell me<br>
which edition of the book.<br>
<br>
Dr. Zellmer</big></font></big>
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