# Reaction Rate Chemistry!?

1)A reaction is said to be diffusion controlled when it occurs as fast as the reactants diffuse through the solution. The following is an example of a diffusion controlled reaction.

The rate constant for this reaction is 1.4x1011 M-1s-1 at 25oC and the reaction obeys the following rate law.

rate = k(H3O+)(OH-)

Calculate the rate of reaction in a neutral solution (pH=7.00).

Rate = ? M/sec

2)Calculate the rate at which N2O4 is formed in the following reaction at the moment in time when NO2 is being consumed at a rate of 0.0683 M/s.

Rate of N2O4 formation = ?M/sec

3)Assume that the instantaneous rate of disappearance of the MnO4- ion in the following reaction is 0.00413 M/s at some moment in time.

What is the rate of appearance of I2 at the same moment?

Rate of I2 appearance = ?M/sec

Help with either of these problems would be helpful! Thanks!

Relevance
• Robert
Lv 4

At pH 7, [H3o+] = 10^-7 = [OH-]

rate = 1.4x10^11 * 10^-7 * 10^-7 = 1.4x10^-3 M s^-1

2 NO2 --> N2O4, so N2O4 is formed at half the rate NO2 is consumed

rate = 0.0342 M/s

assuming the MnO4- goes to Mn2+ and the I2 came from I-, then the I2 is formed at 5/2 the rate of MnO4- disappearance

rate = 0.0103 M/s