[CHM 330] Problem 9.10

[Andrew J. Pounds]

Some of you are struggling with problem 9.10 in the text (which is part 
of the Mastering online homework). The key to unlocking these problems 
is recognizing that you are dealing with EQUAL VOLUMES of EQUIMOLAR 
SOLUTIONS.   Parts B and D seem to be the hardest.

For part B you are told that the equation is first order with respect to 
both A and B.

d[A]dt=k[A][B]\frac{d[A]}{dt}=k[A][B]but remember, these are equal 
volumes and equal concentrations, so [A]=[B]

d[A]dt=k[A][B]=k[A][A]=k[A]2\frac{d[A]}{dt}=k[A][B]=k[A][A]=k[A]^2so you 
can treat this essentially using second order kinetics and use the 
second order integrated rate law to determine the concentrations as a 
function of time.

In part D you are told that the equation is first order with respect to 
A and half-order with respect to B.  Again, employing the fact that 
[A]=[B]..

d[A]dt=k[A][B]1/2=k[A][A]1/2=k[A]3/2\frac{d[A]}{dt}=k[A][B]^{1/2}=k[A][A]^{1/2}=k[A]^{3/2}Use 
the same separation of variable techniques that we used before but apply 
it to this particular problems...

∫[A]0[A]td[A][A]3/2=∫0tkdt\int_{[A]_0}^{[A]_t}\frac{d[A]}{[A]^{3/2}}=\int_0^tkdt

to come up with the integrated rate law that you can then use to solve 
for the concenrations.


-- 
*/Andrew J. Pounds, Ph.D./*
/Professor of Chemistry and Computer Science/
/Director of the Computational Science Program/
/Mercer University, Macon, GA 31207 (478) 301-5627/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://theochem.mercer.edu/pipermail/chm330/attachments/20220329/0286075d/attachment.html>