What is the rate law of a reaction: 2A + 3B → products?

Update: I found out that the coefficients of the chemical reaction are not the exponents in the rate law. It is actually the order of the species during the reaction.

It is known that in the reaction, first order in 2A + 3B → products, A was found to be a first order and B is second order. So, does it mean that the rate law for this reaction is R = k[A][B]2?

I have been taught that R = k[A]x[B]y

Where: R = Rate of the reaction; k = rate constant; A = Concentration of species A; B = Concentration of species B; x = order of reaction with respect to A; and y = order of reaction with respect to B

First question: So, does that mean for the particular reaction: 2A + 3B → products, will have a rate law of R = k[A]2[B]3?

Second Question: How do I determine the x and y? Like what does order of reaction mean?

• R = k[A]^2[B]^3 would be true if the reaction was the result of a simultaneous collision of 5 molecules. We do not know such reactions. Jan 11 at 11:05

If such a reaction "$$\ce{2A + 3B -> }$$ products" occurs, it is the sum of several more elementary reactions, which are taking place successively. Some may be fast, some slower. The rate of the global reaction is the rate of the slowest of these elementary reactions. It can be first or second order, or it can even be more complicated, depending on any catalytic effect. –
If $$\ce{2A + 3B -> \text{product(s)}}$$ describes the stoichiometry of a reaction, than you describe the balance of starting materials against products; this however does not state much about the kinetics, elemental (perhaps rate determining) steps, and overall reaction order described by kinetics.