Cliffs AP Chemistry, 3rd Edition

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VII. Calculations:


II. Reaction Order with Respect to Hydrogen Peroxide


  1. Calculate the initial reaction rate for each trial.


rate time s()

I
s
==∆^3510 # -^4 M

7 - A

. ./
s


50 10 M 1 0638 10 Ms
47

#^45
= #




    • ^h
      . ./
      s




50 10 M 1 0638 10 Ms
47

#^45
= #




    • ^h
      . ./
      s




50 10 M 9 8039 10 Ms
51

#^46
= #




    • ^h
      . ./
      s




50 10 M 8 3333 10 Ms
60

#^46
= #




    • ^h
      . ./
      s




50 10 M 7 1429 10 Ms
70

#^46
= #




    • ^h
      . ./
      s




50 10 M 5 5556 10 Ms
90

#^46
= #




    • ^h




III. Reaction Order with Respect to Hydronium Ion


  1. Calculate the reaction rates as in step 2 of Part II.


log (rate)

log [H 2 O 2 ]

Graph
to find
x slope = order = x

Laboratory Experiments


  • rate time s()


I
s
==∆7A^3510 # -^4 M

..
s


50 10 M 1 1111 10
45

#^45
= #




    • ..
      s




50 10 M 1 0000 10
50

#^45
= #




    • ..
      s




50 10 M 6 66667 10
75

#^46
= #




    • ..
      s




50 10 M 4 80769 10
104

#^46
= #




    • ..
      s




50 10 M 3 84615 10
130

#^46
= #









Find z for each of the five reaction mixtures
and average the results
0.037761+0.0172+(−.193819)+(−.34387)+
(−.31940) = −.802128
−.80 21 28/5 = −.1604256
zero order

Algebraic solution of order z.
log (rate 0 Part II) = log k+z log (1.00 × 10 –5)
log (rate 0 Part III) = log k+z log (3.16 × 10 –^5 )
log(1.00 × 10 −^5 ) = −5.00
log (3.16 × 10 −^5 ) = −4.50
log k = log rate (II) −z (5.0)
log k = log rate (III) −z (4.50)
log rate (II) −z (5.0) = log rate (III) −z (4.50)
z^05 =. h logcrate IIIrate IIm

*formula to calcuate z.

log
z

rate II

rate III
= 05

cm

*..

.

log.
z 05 0 037761

1 0638 10

1 1111 10
5

5
#

#
==





  • dn




*

.

..


.

log
z

1 0000

05 0 0172

9 8039 10

10
6

5
#

#
==





  • dn




*..

.

log.
z 05 0 193819

8 3333 10

6 66667 10
6

6
#

#
==-




    • dn




*

.

..


log.
z

7 14286
05 0 34387

10

4 80769 10
6

6
#

#
==-





  • dn




*

.

..


log.
z

5 55556
05 0 31940

10

3 84615 10
6

6
#

#
==-





  • dn



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