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### Differential vs Integrated

Posted: Mon Mar 05, 2018 8:26 pm
I have a general question as to when to know to use the differential or integrated equations for first, second, or zero order.

Thanks.

### Re: Differential vs Integrated

Posted: Mon Mar 05, 2018 8:35 pm
Usually the question tells you if a reaction is first, second, or zero order, but if you need to calculate it you can by comparing the rates of separate equations and how reactant concentrations change with them.

You use the differential rate law when determining a rate of an equation (either a general rate or a rate at a specific time (t)) and the integrated rate law for finding a specific concentration and deriving the half-life formula.

### Re: Differential vs Integrated

Posted: Wed Mar 07, 2018 4:26 pm
Since differential would be something like rate=k[A]^x[B]^y[C]^z, we can use it to:
calculate the rate given k, concentration of reactants, and order of reactants
calculate the rate constant k given rate, concentration of reactants, order of reactants
etc.
We cannot use it to calculate a new rate given an initial rate, or to calculate the time taken to get from x amount of reactant to y amount of reactant; we must use the integrated rate laws for this. Also, use integrated rate laws to find k given t, [A], and [A] initial.