What is the Slow Step in This General Chem Kinetics Reaction?

[Miike012]

Question 1:

Step 1: 2NO2 (g) + 2SO2 (g) = 2NO (g) + 2SO3 (g)
Step 2: 2NO (g) + O2 (g) = 2NO2 (g)
The reaction is found to be first order with respect to NO2 and SO2, what is the slow step for this reaction?

1. First step
2.Second step
3.Not possible to determine

Question 2 and 3: Look at graph.
Questions are located on the graph...

Thank you.

For Question 1: I believe that it is 3. not possible to determine.
Question 2... number 24 on graph I believe it is 8 J
question 3: I have no clue.

 

[Borek]

The reaction is found to be first order with respect to NO2 and SO2, what is the slow step for this reaction?

Does the second step involve SO₂? Can it be first order with respect to SO₂?

Question 2... number 24 on graph I believe it is 8 J
question 3: I have no clue.

What is the definition of activation energy?

 

[Miike012]

Activation energy: min energy of collision required for a chem reaction...

the second step does not involve SO2... I still don't understnad it though?

 

[Borek]

Activation energy: min energy of collision required for a chem reaction...

That's not completely off, but it doesn't address what is really important here. It is not total energy, but amount of energy needed to start the reaction. 8J is total.

the second step does not involve SO2... I still don't understnad it though?

If it doesn't involve SO₂, can it have ANY order with regards to SO₂?

 

[Miike012]

If it doesn't involve SO2... then no it can not have any order with regards to SO2...

 

[Miike012]

? so what does that mean?

 

[Borek]

If the second step would be the slow one, could it be first order with regards to SO₂?

 

[Miike012]

No... I don't believe so.. I am just not understanding how to determine the slow step.. I know your trying to tell me something but I still am not understanding how SO2 can determine if its a slow or fast step..

 

[Borek]

You know slow step requires presence of SO₂, you also know one of the reactions doesn't involve SO₂ at all. Can it be a slow step then?

 

[Miike012]

I had no idea a slow step REQUIRED SO2... ?

 

[Borek]

That's the conclusion from the information given - if slow step has any order with regard to SO₂, SO₂ must be part of the reaction. This is not some additional rule, this is just application of logic.