## Orders

$\frac{d[R]}{dt}=-k; [R]=-kt + [R]_{0}; t_{\frac{1}{2}}=\frac{[R]_{0}}{2k}$

Timmy Nguyen Dis 1I
Posts: 107
Joined: Sat Aug 17, 2019 12:17 am

### Orders

How do we know which order the reaction is?

asannajust_1J
Posts: 105
Joined: Wed Sep 11, 2019 12:16 am
Been upvoted: 1 time

### Re: Orders

the total order of the reaction is the sum of the exponential coefficients. This can be determined based on graphs, a given rate law, or an integrated rate law.

jisulee1C
Posts: 149
Joined: Thu Jul 25, 2019 12:17 am

### Re: Orders

the order can also be determined by the given rate constant and the units or from a table with given concentrations and rates

Brianna Becerra 1B
Posts: 117
Joined: Fri Aug 02, 2019 12:16 am

### Re: Orders

A first-order reaction means that there is one reactant or molecule present in the rate law. A second-order rate law either has two of the same reactant (rate law would be squared) or two different ones (they would be multiplied by each other). Two examples of second-order reactions are rate=k[CO2]^2 or rate=k[CO2][H2O].

Mariah
Posts: 104
Joined: Fri Aug 02, 2019 12:16 am

### Re: Orders

asannajust_1J wrote:the total order of the reaction is the sum of the exponential coefficients. This can be determined based on graphs, a given rate law, or an integrated rate law.

Would the graphs be given to us?

Michael Nguyen 1E
Posts: 120
Joined: Sat Aug 17, 2019 12:17 am

### Re: Orders

I believe that if we need to determine the order of a reaction based on graphs, then they will most likely provided the graphs that we need.

Noe BM 1J
Posts: 50
Joined: Sat Sep 07, 2019 12:17 am

### Re: Orders

How would we know the order of the reaction if we are given an integrated rate law?

asannajust_1J wrote:the total order of the reaction is the sum of the exponential coefficients. This can be determined based on graphs, a given rate law, or an integrated rate law.

Noe BM 1J
Posts: 50
Joined: Sat Sep 07, 2019 12:17 am

### Re: Orders

As far as I know, we never include products in the rate law, correct?

Brianna Becerra 1B wrote:A first-order reaction means that there is one reactant or molecule present in the rate law. A second-order rate law either has two of the same reactant (rate law would be squared) or two different ones (they would be multiplied by each other). Two examples of second-order reactions are rate=k[CO2]^2 or rate=k[CO2][H2O].

Oduwole 1E
Posts: 100
Joined: Fri Aug 02, 2019 12:16 am

### Re: Orders

Timmy Nguyen Dis 1I wrote:How do we know which order the reaction is?

You can use the given rate constant and the units or from a table with given concentrations and rates.