## different units

Katie Bart 1I
Posts: 104
Joined: Sat Aug 24, 2019 12:16 am

### different units

Why are the units different in first, second, etc. ordered reactions?

Aiden Metzner 2C
Posts: 104
Joined: Wed Sep 18, 2019 12:21 am

### Re: different units

Each different ordered reactions involve having the concentrations be increased to certain powers. ^2 for second order. Therefore the units are changed by that order as well.

EvanWang
Posts: 101
Joined: Sat Sep 07, 2019 12:16 am

### Re: different units

It is because you want the right units in the end when you multiply everything to find the rate using the differential or integrative rate law. In a reaction with an overall order of 4 for example, you will have the unit of mol/L multiplied by itself 4 times, so the units of k must be different so that the rate is in moles per liter per second.

Maya Pakulski 1D
Posts: 105
Joined: Thu Jul 11, 2019 12:17 am

### Re: different units

The units of k specifically in different order reactions are
zero-order M/s
first-order 1/s
second-order 1/M*s

Mitchell Koss 4G
Posts: 128
Joined: Sat Jul 20, 2019 12:17 am

k=rate/[A]

rate=M/s
[A]=M