## linear graph

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

josmit_1D
Posts: 107
Joined: Fri Aug 09, 2019 12:17 am

### linear graph

for a second order reaction, what equation gives a linear plot?

Samuel Tzeng 1B
Posts: 103
Joined: Sat Aug 24, 2019 12:15 am

### Re: linear graph

1/[A] vs time

Hiba Alnajjar_2C
Posts: 108
Joined: Fri Aug 09, 2019 12:17 am

### Re: linear graph

You would get a linear plot when you graph 1/[A] vs. time. This makes a bit more sense when you look at the integrated rate law for a second order reaction: 1/[A]=kt+1/[A]o

(In this plot, k would be the slope).

005162520
Posts: 101
Joined: Tue Sep 24, 2019 12:17 am

### Re: linear graph

how would we determine if it is a positive or negative slope? Or do we just have to memorize it ?

Sofia Barker 2C
Posts: 101
Joined: Wed Sep 18, 2019 12:21 am

### Re: linear graph

005162520 wrote:how would we determine if it is a positive or negative slope? Or do we just have to memorize it ?

If given a set of [A] values vs time, you can determine the slope by taking the inverse of each [A] value, which gives the 1/[A] value, and see if it increases or decreases over time. That way you can see if the graph's slope will be positive (increasing values) or negative (decreasing values).

Nathan Nakaguchi 1G
Posts: 102
Joined: Wed Sep 18, 2019 12:22 am
Been upvoted: 1 time

### Re: linear graph

A linear plot is in the form y=mx+b and for second order 1/[A] = kt + 1/[A]0 so the plot is 1/[A] versus time.

ABombino_2J
Posts: 102
Joined: Thu Jul 11, 2019 12:15 am

### Re: linear graph

To see if the slope is positive or negative you take the value of k from the equation.

Maika Ngoie 1B
Posts: 97
Joined: Fri Aug 02, 2019 12:16 am

### Re: linear graph

For a second order reaction the graph of ln[A] vs time will yield a straight line