## Instantaneous rate of change

205150314
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Joined: Wed Feb 20, 2019 12:16 am

### Instantaneous rate of change

Is the equation of the instantaneous rate of change (-d[A]/adt) the same as the differential rate law (K[R]^n)?
If it is then why is it that the differential rate law doesnt have a negative and the instantaneous does?

Ryan Yee 1J
Posts: 101
Joined: Sat Aug 17, 2019 12:16 am

### Re: Instantaneous rate of change

In the first instance (-d[A]/adt), it measures the rate of the decrease of the reactant, but the second instance (K[R]^n) was determined experimentally. It still shows the reactant decreasing, but this time including the rate constant, K, so that you can write rate as a function of concentration.

KnarGeghamyan1B
Posts: 102
Joined: Fri Aug 09, 2019 12:15 am

### Re: Instantaneous rate of change

The instantaneous rate law has a negative because the amount of reactant decreases as the reaction takes place.

Alex Tchekanov Dis 2k
Posts: 118
Joined: Sat Aug 24, 2019 12:16 am

### Re: Instantaneous rate of change

Also keep in mind that if the rate law contains multiple molecules, you can still find the rate of the reaction in relation to one specific molecule my setting the rate law equal to the instantaenous rate law and solving for your molecule.