## Units of k

Tinisha 1G
Posts: 69
Joined: Fri Sep 28, 2018 12:17 am

### Units of k

Can someone show how to derive the units of k for zero, first, and second order reactions?

Posts: 60
Joined: Tue Nov 28, 2017 3:02 am

### Re: Units of k

A Khan Academy video best explains how to derive K without memorization:

Xingzheng Sun 2K
Posts: 62
Joined: Fri Sep 28, 2018 12:29 am

### Re: Units of k

The unit of k for a zero-order reaction is mol L-1 s-1; for a first-order reaction is s-1; For a second-order reaction is L mol-1 s-1.

Joonsoo Kim 4L
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

### Re: Units of k

since the equation for rate law is rate=k[A]^n, and the units for rate is mol/(L*s) and the units for [A]^n is (mol/L)^n, you can derive the units for k just by solving for units depending on the value of n.

Rhea Churi 4K
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: Units of k

Zero-order reaction is mol L-1 s-1
First-order reaction is s-1
Second-order reaction is L mol-1 s-1.

Salena Chowdri 1I
Posts: 66
Joined: Fri Apr 06, 2018 11:02 am

### Re: Units of k

we know that the units for rate are mol.L-1.s-1

Zero order: rate =k[A]^0
so units of k have to be the same as the units for the rate

First order: rate =k[A]
the multiplication of the units of k and units of concentration of A (i.e mol.L-1) should result in the units for the rate; thus, units of k is s^-1

You can do the same for second order and so on!

Return to “Method of Initial Rates (To Determine n and k)”

### Who is online

Users browsing this forum: No registered users and 2 guests