## Slope of k

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

Ashley Van Belle 2B
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### Slope of k

Why do the zero order and first order reactions have a negative slope, while the second order has a positive slope? Will we need to know how to derive these formulas as well?

Monica Habashy 3A
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### Re: Slope of k

Second order reactions are 1/A vs time therefore the slope increases as concentration decreases which is why the slop for that is positive.

Kathy Vu 3L
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Joined: Fri Jul 15, 2016 3:00 am

### Re: Slope of k

When you derive the equation for a zero and first order reactions by integrating, it comes out to be -kt, as opposed to integrating the second order reaction and having it come out to be kt. Therefore the slope is negative for zero and first order.

Katherine_Zhuo_3B
Posts: 23
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Slope of k

For zero and first order reactions, the slope = -k. For second order reactions, the slope = +k.