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### unique rate

Posted: Mon Mar 11, 2019 9:39 pm
what is the difference between a unique rate vs. an instantaneous rate?

### Re: unique rate

Posted: Mon Mar 11, 2019 9:48 pm
Unique rate of reaction looks like $-\frac{1}{C}*\frac{\Delta \left \lfloor R1 \right \rfloor}{\Delta t}$

and instantaneous reaction has the form $\lim_{x\rightarrow 0} \frac{\Delta \left [ concentration \right ]}{dt}$ or $\frac{d\left [ concentration \right ]}{dt}$

the instantaneous rate is more accurate.

### Re: unique rate  [ENDORSED]

Posted: Mon Mar 11, 2019 9:51 pm
I found this posted by chem mod in another post regarding the same question:
"AVERAGE RATE = (CONC(t2) − CONC(t1))/(t2 −t1) = ∆CONC/∆t

INSTANTANEOUS RATE = −(d[R])/dt
OR
INSTANTANEOUS RATE = (d[P])/dt

AVERAGE & INSTANTANEOUS RATES CAN BE DIFFERERENT FOR THE INDIVIDUAL R & P.
THINK OF THEM AS THE EXPERIMENTALLY MEASURED RATES (COLLECTED DATA) OVER LONG TIME INTERVALS (∆) OR SHORT TIME INTERVALS (d).

UNLIKE THE UNIQUE RATE WHICH IS CALCULATED AND IS THE SAME FOR ALL R & P IN THAT ‘UNIQUE’ REACTION WHERE:

UNIQUE RATE = −1/a (d[A])/dt = 1/b (d[B])/dt = 1/c (d[C])/dt

IN THE REACTION: a A ---> b B + c C"

### Re: unique rate

Posted: Sat Mar 16, 2019 3:31 pm
these were very helpful thank you so much