Rate of disappearance based on reaction order

[Lifeman]

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So lets say I have an overall reaction of 2A + B = C

If they say its a 2nd order reaction, can I say that both [A] and decrease in a 2nd order fashion? I thought that [A] would have to be decreasing twice as fast as due to stoichiometry?

I am a bit confused because I see all these graphs with [reactants] vs. time, but they never say which reactant, and don't reactants disappear at different rates due to their coefficients?

 

[monkeyvokes]

Is this an elementary equation? it likely is not. reaction orders are independent of stoichiometry and determined experimentally

 

[Lifeman]

Thank you, but I wasn't asking how reaction orders are determined.

 

[monkeyvokes]

If they say its a 2nd order reaction, can I say that both [A] and decrease in a 2nd order fashion?

the rate equation for the order is because of the rate limiting step I believe. Your over all reaction isn't elementary, so you can't really say what reactants are decreasing in a second order fashion, I think

What do you think?