## Example 15.4

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

Abel Thomas 2C
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### Example 15.4

Since we are not allowed to use a graphing calculator, how would we determine whether the problem in example 15.4 was first order? Would we be told that the graph is first order or that it is linear?

Chem_Mod
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### Re: Example 15.4

If you are given 3 points, each with time and concentration, you could figure out which orientation of concentration ([A], ln[A], or 1/[A]) leads to a linear slope with respect to time. This could be done with a scientific calculator, considering that slope = deltaY/deltaX.

Hannah Chew 2A
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### Re: Example 15.4

In example 15.4, they give you the experimental data of concentration versus time. To figure out if it is first order, you can take the natural log of all the concentration data on your scientific calculator and plot that data. You can also tell it's linear because the ln[concentration] decreases relatively the same amount across equal intervals of time. So while a graphing calculator is a lot easier, it is still very doable on a scientific calculator.

Chem_Mod
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### Re: Example 15.4

A scientific calculator should be sufficient to solve any problem that you will encounter for your assessments. Also, you can use your knowlegde of 0th, 1st, and 2nd order in a graphical and equational sense to help you out if appropriate.