## General Rate Laws

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

Johnathan Smith 1D
Posts: 108
Joined: Wed Sep 11, 2019 12:16 am

### General Rate Laws

Why do we focus on the reactants when we are determining the rate laws?

Alice Chang 2H
Posts: 101
Joined: Fri Aug 30, 2019 12:18 am

### Re: General Rate Laws

According to this site: https://courses.lumenlearning.com/boundless-chemistry/chapter/the-rate-law-concentration-and-time/

The rate law for a chemical reaction is an equation that relates the reaction rate with the concentrations or partial pressures of the reactants.

So, I think it's because rate laws are to measure how fast at certain concentrations of reactants will form products when compared to time. Which is why rate laws are based on reactants.

RasikaObla_4I
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

### Re: General Rate Laws

In the beginning of a reaction, there are no products present so we use the initial concentrations of the reactants because only the forward reaction occurs.

Simon Ketema_1F
Posts: 16
Joined: Wed Nov 13, 2019 12:26 am

### Re: General Rate Laws

The purpose rate law is to determine the rate of the reaction from reactants to products and relate it to the concentrations of reactions as the reaction progresses.

Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

### Re: General Rate Laws

There are no products being formed yet so the rate depends on the reactants.

Ellen Amico 2L
Posts: 101
Joined: Thu Sep 19, 2019 12:16 am

### Re: General Rate Laws

By using the initial rates and initial concentrations of the reactants, it's easier to determine the rate law. This is because when the products start to form they can sometimes affect the rate law and change it. If we only focus on the reactants at the start of the reaction we don't have to worry about the products.

Jeremy_Guiman2E
Posts: 82
Joined: Fri Sep 28, 2018 12:29 am

### Re: General Rate Laws

Rate laws would look at reactants because we are using initial concentrations of reactants to determine rate into product creation.

rohun2H
Posts: 100
Joined: Wed Sep 18, 2019 12:19 am

### Re: General Rate Laws

We calculate the initial rate (when there are no products present).