# rate equation and overall equation

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#1
if something is in rate equation does it have to be in overall equation too?
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3 years ago
#2
(Original post by Iconic_panda)
if something is in rate equation does it have to be in overall equation too?
Yes - the reactants in the rate equation will be in the rate determining step.
0
3 years ago
#3
Rate equation or rate law is the expression indicating the relationship between rate of reaction and concentration of reactants. It will be something like Rate = k[H2]^2[O2]But overall equation is the chemical equation representing the reaction. It will be something like2H2 O2 --> 2H2OBoth will be different
0
3 years ago
#4
(Original post by srinivasanchemi)
Rate equation or rate law is the expression indicating the relationship between rate of reaction and concentration of reactants. It will be something like Rate = k[H2]^2[O2]But overall equation is the chemical equation representing the reaction. It will be something like2H2 O2 --> 2H2OBoth will be different
Both don't have to be different, sometimes the rate equation can be the same as the overall equation; the example you gave is an example of this.

The rate equation you gave shows 2 molecules of H2 reacting with one molecule of O2 - this matches the overall equation's stoichiometry. This will imply that the entire reaction is the rate determining step.
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#5
the specie in rate equation doesn't have to be in overall equation, just saying
0
3 years ago
#6
(Original post by Iconic_panda)
if something is in rate equation does it have to be in overall equation too?
not necessarily i think?? e.g. if the reaction involves a catalyst, the catalyst can (will?) appear in the rate equation (since a catalyst affects the rate of reaction), but the catalyst won't appear in the overall equation

have a look at question 5c in this pack of exam qs

http://pmt.physicsandmathstutor.com/...0%8B3%20QP.pdf

5c) How can you tell that H+ acts as a catalyst in this reaction?

"Appears in rate equation (1)

does not appear in (stoichiometric / overall) equation (1) "

hope this helps
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