[samiam991]

I'm getting a bit confused because my textbook says one thing and my class manual shows another.

manual shows
first order rate of reaction
A-->product
-dA/dt=k[A]

second order rate of reaction
2A-->product
-dA/dt=k[A]²
**The textbook says the coefficient of the reactants has nothing to do with the exponents in the rate law.


on the side..
 Pseudo first order rate of reaction.
so if a reactants concentration is constant because it is a catalyst or it is in excess relative to the other reactants it's concentration can be grouped with the rate constant?
A+H20-->products

the example in the manual says K'[A][H20] is technically second order? how do we know this just because the exponents of the reactant concentrations add up to 2?

[Schrödinger]

manual shows
first order rate of reaction
A-->product
-dA/dt=k[A]

second order rate of reaction
2A-->product
-dA/dt=k[A]²
**The textbook says the coefficient of the reactants has nothing to do with the exponents in the rate law.

True. Order and molecularity of the reaction need not be related. It just so happens in certain simple cases that they turn out to be equal. (look up order of a reaction and molecularity if unfamiliar)

Pseudo first order rate of reaction.
so if a reactants concentration is constant because it is a catalyst or it is in excess relative to the other reactants it's concentration can be grouped with the rate constant?
A+H20-->products

Yes.

the example in the manual says K'[A][H20] is technically second order? how do we know this just because the exponents of the reactant concentrations add up to 2?

Order = sum of all exponents