## Rate Law dependent on Reactants [ENDORSED]

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

Jessica Yang 1J
Posts: 55
Joined: Fri Sep 29, 2017 7:03 am

### Rate Law dependent on Reactants

Why is the rate law only include the concentration of reactants along with k? For example, all of the rate laws in table 15.1

Thanks!

Jasmine Wu 1L
Posts: 55
Joined: Thu Jul 27, 2017 3:00 am
Been upvoted: 1 time

### Re: Rate Law dependent on Reactants

For a chemical reaction aA + bB $\rightarrow$ cC + dD the formula for rate is k[A]a[B]b, where k is the rate constant, [A] is the concentration of reactant A, and [B] is the concentration of reactant B. Each reaction has its own unique rate law and rate constant, so Table 15.1 is just generalizing for you what the rate law would be when given a reaction.

Salma Quintanilla 1J
Posts: 29
Joined: Wed Nov 23, 2016 3:02 am

### Re: Rate Law dependent on Reactants

The rate constant (k) depends on the temperate and activation energy.

Magdalena Palavecino 1A
Posts: 54
Joined: Fri Sep 29, 2017 7:04 am

### Re: Rate Law dependent on Reactants

How would we take into account temperature and activation energy when calculating k? Also, I'm confused about all the meanings we have given K in this class. Is k here the rate or the equilibrium constant?

Chem_Mod
Posts: 17238
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 367 times

### Re: Rate Law dependent on Reactants  [ENDORSED]

k is the rate constant, while K is the equilibrium constant generally. You don't need to factor the temperature or activation energy into an calculations of k, it is just a conceptual fact that you should know. There is no mathematical way to determine reaction rates besides experimenting.