overall order of the rxn (sapling #7)

[sabrina ghalambor 2J]

hi! i'm a bit confused on what the overall order of a reaction means and why we can just add those numbers together? i know how to find values for m,n, and l experimentally but i don't understand why for the overall order of the reaction we just add those values together? thank you in advance!

[Alex Mele 2A]

The overall order of a reaction is just defined as the sum of the individual orders. In general, it measures the how sensitive a reaction rate is to changes in reactant concentrations.

[Gabby Magat 3F]

I'm not super sure, but I think it may be because of what the different orders mean physically. For example, the zero-order means the rate is independent of the concentration of that reactant, so it makes sense that if [A] does not impact the rate of the whole reaction, N = 0 and we just add 0 to M and L. In other words, the order of [A] does not impact the order of the entire reaction because 0 does not affect the sum.

I hope this kind of helps, I'd love to know if someone has a better explanation!

[sabrina ghalambor 2J]

but would an overall rxn order of (for example) 5 mean anything without the context of the problem? because that could involve multiple first order reactants or one first order and 2 second, with infinite possibility for zero-order reactants?

[Sable Summerfield]

How do we know C is the zero order reactant?

[Sable Summerfield]

hi! i'm a bit confused on what the overall order of a reaction means and why we can just add those numbers together? i know how to find values for m,n, and l experimentally but i don't understand why for the overall order of the reaction we just add those values together? thank you in advance!

As well, you can see that the orders are 0, 1, and 2..... so if you add those together you will get your answer of the overall order.

For the rate law of the equation you leave out [C] because it will just be one as the coefficient is 0 and anything to the 0 is equal to one.

[AndrewNguyen_2H]

Try adding the individual orders.

[RylanPurificacion 3J]

How do we know C is the zero order reactant?

We know because in the context of the problem, there are two examples where the concentrations of [A] and [B] stay the same and [C] changes, yet their rates do not change. Since the rates do not change, that means that the concentration of [C] cannot affect the rates, which means that C is a zero order reactant.

but would an overall rxn order of (for example) 5 mean anything without the context of the problem? because that could involve multiple first order reactants or one first order and 2 second, with infinite possibility for zero-order reactants?

I'd like to know the answer to this as well. If anyone knows, I'd appreciate it.

[sabrina ghalambor 2J]

How do we know C is the zero order reactant?

We know because in the context of the problem, there are two examples where the concentrations of [A] and [B] stay the same and [C] changes, yet their rates do not change. Since the rates do not change, that means that the concentration of [C] cannot affect the rates, which means that C is a zero order reactant.

but would an overall rxn order of (for example) 5 mean anything without the context of the problem? because that could involve multiple first order reactants or one first order and 2 second, with infinite possibility for zero-order reactants?

I'd like to know the answer to this as well. If anyone knows, I'd appreciate it.

i actually asked Dr.Lavelle about this in OH and if i remember correctly, he said that the overall # we find also tells us about the speed of the overall rxn and its susceptibility to changes in concentration

[RyanKopeikin_2I]

To my understanding you just add the orders of the reactants in the rate law together to get the overall rxn order..