## Graphs

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

Ellis Song 4I
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Graphs

Can someone explain and summarize what the graphs for each order reaction looks like and what they mean?

Tanmay Singhal 1H
Posts: 143
Joined: Sat Jul 20, 2019 12:16 am

### Re: Graphs

this image does a good job of graphing them. i believe it shows how one is related to the other and how fast it is used up

Wendy 1E
Posts: 111
Joined: Sat Aug 17, 2019 12:17 am
Been upvoted: 2 times

### Re: Graphs

I suggest looking at the email that Dr. Lavelle sent us through email titled "Week 10 Review." It has the graphs for each order. Hope this helps!

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

### Re: Graphs

A first-order reaction will have a straight-line graph of ln[A] v. t
A second-order reaction will have a straight-line graph of 1/[A] v. t
A zero-order reaction will have a straight-line graph of [A] v. t

The first-order and zero-order graphs will have negative slopes while the second-order graph will have a positive slope.

Matt F
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

### Re: Graphs

The key to understanding the graphs is to look at the axis labels, especially if the plot is linear. As mentioned above, graphs of [A], ln[A], and 1/[A] vs t correspond to zero order, first order, and second order reactions when the plots are linear

Juliana Chopelas 1A
Posts: 50
Joined: Sat Aug 24, 2019 12:16 am

### Re: Graphs

Zero order reaction: graph is concentration A v time, with a straight line where k is -slope
First order reaction: graph is ln of concentration A v time, with a straight line where k is -slope
Second Order reaction: graph is 1/concentration A v time, with a straight line where k is +slope

Juliet Stephenson 4E
Posts: 100
Joined: Wed Sep 18, 2019 12:21 am

### Re: Graphs

Units of k also change for each order. Rate will always equal Moles/liter.seconds but since we are sometimes squaring or cubing concentration, K will have different units for each order. Most charts contain some reference to this.

Emily Burghart 1k
Posts: 50
Joined: Wed Sep 18, 2019 12:17 am

### Re: Graphs

This is a good chart for reference.
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