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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: Fr9219 on May 11, 2013, 08:40:30 AM

Title: Steady state approach for consumption of reactant?
Post by: Fr9219 on May 11, 2013, 08:40:30 AM
Do you determine the steady state rate law for consumption of a reactant in the same way as you determine the rate law for the formation of a product?

Here is the equation:

2NO + H2 ----> N20 + H20

The mechanistic equations are:

2NO ----> N2O2 (k1)
N2O2 ----> 2NO (k2)
N2O2 + H2 ----> N20 + H20 (k3)

The question is: Determine the rate law for the consumption of H2

N2O2 is the intermediate.

Is d[H2]/dt = [N2O2] [H2] correct?

PLEASE HELP ME ?!
Title: Re: Steady state approach for consumption of reactant?
Post by: Babcock_Hall on May 11, 2013, 01:07:50 PM
I am not a professional kineticist, but your expression has no rate constants in it.  Also, were you told to use the steady-state approximation for this problem?
Title: Re: Steady state approach for consumption of reactant?
Post by: curiouscat on May 11, 2013, 02:35:43 PM
1. You need a rate constant

2. Your sign's wrong

3. N2O2 needs to be eliminated
Title: Re: Steady state approach for consumption of reactant?
Post by: Miffymycat on June 03, 2013, 07:32:15 PM
is it d[H2]/dt = - k3k1 [NO]2[H 2]/(k2 + k3[H]2)?
Title: Re: Steady state approach for consumption of reactant?
Post by: Miffymycat on June 03, 2013, 07:34:42 PM
sorry d[H2]/dt = - k3k1[NO]2[H2]/(k2 + k3[H2])?