## Half-life of Second-Order

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

Kate Zeile 2D
Posts: 39
Joined: Sat Jul 22, 2017 3:01 am

### Half-life of Second-Order

In the textbook, at the end of section 15.6, it gives a table detailing all the components of each order of a reaction. For the half-life of a second-order reaction, it writes that the equation is t1/2=$\frac{1}{k[A]}$. However, underneath that, it says "(not used)." Does anyone know what this means/why this is the case?

Austin Ho 1E
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 2 times

### Re: Half-life of Second-Order

I believe that, in general, the textbook won't be asking you questions about the half life of 2nd order reactions. Therefore, the equation is not used, but is still provided so you know what it is in theory.

Kayla Tchorz-Dis 1F
Posts: 30
Joined: Thu Jul 13, 2017 3:00 am

### Re: Half-life of Second-Order

it is definitely correct and useable, so I'm not really sure why it would say don't use it. Maybe we won't be asked this question often.