Question

Perform a linear regression to determine the slope of the plot of Ln(A/A0) vs time that is discussed on page 16. Recall from page 12 that the slope for this plot is -k (where k is the radioactive decay constant). Input below the value for k obtained from this data set.

Answer=0.0715

Note that your k value should be positive, since it is the negative of the slope. All reaction rate constants are positive values. The units for this k are min-1, since the time data values had units of minutes.

For radioactive decay (and for all reactions with first-order kinetics), the reaction half-life, t1/2, discussed on page 11, is related to k by the following equation:

t1/2 = Ln2 / k

Using this relation, calculate t1/2 for the radioactive isotope used in the experiment and input the value below:

___________?____________min

You can check your half-life for correctness by examining the plot of the original data. How long does it take (approximately) for the amount present at a given time to drop to half that amount?

y=-0.0715x-0.0002

R2=1

Data Set

Time (minutes)
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
16.00
18.00
20.00
22.00
24.00

Ln(A/A0)
0.000
-0.142
-0.285
-0.428
-0.573
-0.717
-0.858
-1.000
-1.152
-1.287
-1.427
-1.570
-1.715

  

Answer 1