## Slopes of a plot

$\frac{d[R]}{dt}=-k[R]; \ln [R]=-kt + \ln [R]_{0}; t_{\frac{1}{2}}=\frac{0.693}{k}$

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JulieAljamal1E
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Joined: Fri Sep 28, 2018 12:24 am

### Slopes of a plot

Is the slope of a plot of a first order negative?

Meghanhe1l
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Joined: Fri Sep 28, 2018 12:17 am

### Re: Slopes of a plot

yes it is

Gillian Ward 1F
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Joined: Fri Sep 28, 2018 12:27 am

### Re: Slopes of a plot

Since first order is ln[A]=-kt+ln[A]o it has a negative slope due to the -k.

SydBenedict2H
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Joined: Wed Nov 08, 2017 3:00 am

### Re: Slopes of a plot

The only one that isn't -k is is 2nd-order, which is just k (+k).

Giselle1B
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Joined: Fri Sep 28, 2018 12:19 am

### Re: Slopes of a plot

Zero Order also has a negative slope. Think of the equations as mx+b. The Slope (mx) is similar to kt in the order process formulas.

Douglas Nguyen 2J
Posts: 71
Joined: Fri Sep 28, 2018 12:15 am

### Re: Slopes of a plot

Yes, both zero and first order reactions' linear plots have slope as -k.

Kate Swertfager
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Joined: Wed Sep 18, 2019 12:17 am

### Re: Slopes of a plot

Yes the graph of the first order has a negative slope. The slope is -k and since k is always positive the slope is always negative for 1st order.

Radha Patel 4I
Posts: 97
Joined: Tue Feb 12, 2019 12:15 am

### Re: Slopes of a plot

Zeroth Order plot is negative (-k). First order plot is negative (-k). Second order plot is positive (+k). Also Lavelle hasn't discussed it yet I believe, but the units of the rate constant k in Zeroth Order is M/s, in First Order is 1/s, and Second Order is M^-1* s^-1

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