## CHM 112 Section 1

Homework Assignment #3
##### Due January 30, 2006 by 8:05 a.m.

Practice (not to be turned in): 13.27, 13.30, 13.32, 13.33, 13.34, 13.38, 13.40, 13.41, 13.47, 13.48

Consider the reaction

A(g) products

Choose the data set corresponding the to last digit in your Student ID Number.

Plot the data as:
a) a zero order reaction
b) a first order reaction
c) a second order reaction

Based on these plots, determine the order of reaction and the rate constant, including units. Use a full, clean sheet of graph paper for each plot (spread sheets plots are NOT acceptable). Be sure that the axes are labeled and that the data uses the entire plotted area of your graph.

 data set 0 time (s) [A] 0.00 0.100 0.10 0.086 0.20 0.074 0.30 0.064 0.40 0.055 0.50 0.047 0.60 0.041 0.70 0.035 0.80 0.030 0.90 0.026 1.00 0.022

The first order plot is linear with a slope = –1.5 so the rate constant k = 1.5 s–1

 data set 1 time (s) [A] 0.000 0.100 0.005 0.090 0.010 0.080 0.015 0.072 0.020 0.064 0.025 0.058 0.030 0.052 0.035 0.046 0.040 0.041 0.045 0.037 0.050 0.033

The first order plot is linear with a slope = –22 so the rate constant k = 22 s–1

 data set 2 time (s) [A] 0.0000 0.100 0.0010 0.090 0.0020 0.081 0.0030 0.072 0.0040 0.065 0.0050 0.058 0.0060 0.052 0.0070 0.047 0.0080 0.042 0.0090 0.038 0.0100 0.034

The first order plot is linear with a slope = –108 so the rate constant k = 108 s–1

 data set 3 time (s) [A] 0.00 0.100 0.10 0.088 0.20 0.078 0.30 0.070 0.40 0.064 0.50 0.059 0.60 0.054 0.70 0.051 0.80 0.047 0.90 0.044 1.00 0.042

The second order plot is linear with a slope = +14 so the rate constant k = 14 M–1 s–1

 data set 4 time (s) [A] 0.000 0.100 0.010 0.082 0.020 0.069 0.030 0.060 0.040 0.053 0.050 0.048 0.060 0.043 0.070 0.039 0.080 0.036 0.090 0.033 0.100 0.031

The second order plot is linear with a slope = +224 so the rate constant k = 224 M–1 s–1

 data set 5 time (s) [A] 0.0 0.100 1.0 0.081 2.0 0.068 3.0 0.058 4.0 0.051 5.0 0.045 6.0 0.041 7.0 0.037 8.0 0.034 9.0 0.032 10.0 0.029

The second order plot is linear with a slope = +2.4 so the rate constant k = 2.4 M–1 s–1

 data set 6 time (s) [A] 0.0000 0.100 0.0025 0.092 0.0050 0.084 0.0075 0.076 0.0100 0.068 0.0125 0.060 0.0150 0.052 0.0175 0.044 0.0200 0.036 0.0225 0.028 0.0250 0.020

The zero order plot is linear with a slope = –3.2 so the rate constant k = 3.2 M s–1

 data set 7 time (s) [A] 0.000 0.100 0.025 0.092 0.050 0.083 0.075 0.075 0.100 0.066 0.125 0.058 0.150 0.049 0.175 0.041 0.200 0.032 0.225 0.024 0.250 0.015

The zero order plot is linear with a slope = –0.34 so the rate constant k = 0.34 M s–1

 data set 8 time (s) [A] 0.00 0.100 0.50 0.092 1.00 0.084 1.50 0.076 2.00 0.068 2.50 0.060 3.00 0.052 3.50 0.044 4.00 0.036 4.50 0.028 5.00 0.020

The zero order plot is linear with a slope = –0.016 so the rate constant k = 0.016 M s–1

 data set 9 time (s) [A] 0.00000 0.100 0.00025 0.089 0.00050 0.079 0.00075 0.070 0.00100 0.062 0.00125 0.055 0.00150 0.049 0.00175 0.043 0.00200 0.038 0.00225 0.034 0.00250 0.030

The first order plot is linear with a slope = –483 so the rate constant k = 483 s–1