## Units pseudo rate law

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

CHEM 14B Lover
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### Units pseudo rate law

What are the units of for pseudo rate law constant (k')?

Rebecca Altshuler 1D
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Joined: Fri Sep 28, 2018 12:15 am

### Re: Units pseudo rate law

I believe it depends on the order of the reaction. For example, for a second order rate constant rate = k[A][B], if we assume B is in large excess, then we can say rate = k'[A] where k' = k[B]. In this case, the units of k are 1/M*s, so when we multiply this by the concentration of B we get 1/s as the units of k'. This makes sense because in this equation k' is acting as a first order rate constant, and should have the units 1/s.

Matthew Mar 1J
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Joined: Fri Sep 28, 2018 12:15 am
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### Re: Units pseudo rate law

So if it's a pseudo first order reaction, treat it as if its just a normal first order reaction to find the units and so on.