Problem: The initial rate for the oxidation of iron(II) by cerium(IV)Ce4+ + Fe2+   ------->  Ce3+ + Fe3+ Is measured at several different initial concentrations of the two reactantsThe rate law for the reaction is:rate law = k[Ce4+][Fe2+]  Experiment        [Ce+4]                            [Fe2+]                          Initial Rate (M/s)1                     1.10 x10-5                       1.80 x10-5                          2.00 x10-72                     1.10 x10-5                       2.80 x10-5                          3.10 x10-73                     3.40 x10-5                       2.80 x10-5                          9.50 x10-7b) Calculate the rate constant (k) and give its units.

FREE Expert Solution

We’re being asked to calculate the value of the rate constant (k) based on the reaction and data given.


Recall that the rate law only focuses on the reactant concentrations and has a general form of:

rate law=kAxBy

k = rate constant
A & B = reactants
x & y = reactant orders


Calculate the value of the rate constant

Go back to the given data. You can use any experimental data to calculate for k, but let’s use the 1st data for this calculation:


  Experiment        [Ce+4]                            [Fe2+]                          Initial Rate (M/s)

1                     1.10 x10-5                       1.80 x10-5                          2.00 x10-7
2                     1.10 x10-5                       2.80 x10-5                          3.10 x10-7

3                     3.40 x10-5                       2.80 x10-5                          9.50 x10-7


View Complete Written Solution
Problem Details

The initial rate for the oxidation of iron(II) by cerium(IV)

Ce4+ + Fe2+   ------->  Ce3+ + Fe3+ 

Is measured at several different initial concentrations of the two reactants

The rate law for the reaction is:

rate law = k[Ce4+][Fe2+]

  Experiment        [Ce+4]                            [Fe2+]                          Initial Rate (M/s)

1                     1.10 x10-5                       1.80 x10-5                          2.00 x10-7
2                     1.10 x10-5                       2.80 x10-5                          3.10 x10-7
3                     3.40 x10-5                       2.80 x10-5                          9.50 x10-7


b) Calculate the rate constant (k) and give its units.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Rate Law concept. You can view video lessons to learn Rate Law. Or if you need more Rate Law practice, you can also practice Rate Law practice problems.