Half-life of second order reactions

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

Nancy Le - 1F
Posts: 52
Joined: Fri Sep 29, 2017 7:07 am

Half-life of second order reactions

Is the half-life of a second order reaction dependent or independent on reaction concentration?

Ya Gao
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Joined: Fri Sep 29, 2017 7:04 am
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Re: Half-life of second order reactions

Half life of a second order reaction is dependent on the initial concentration since the the half life equals to 1/k[Ao]

RyanS2J
Posts: 32
Joined: Thu Jul 27, 2017 3:00 am

Re: Half-life of second order reactions

The half-life of a second order reaction is dependent on reactant concentration. The second order half-life is the time it takes for [A]t in 1/[A]t = 1/[A]o + kt to become half of [A]o. Substituting in [A]o/2 for [A]t yields that the half-life is 1/k[A]o. That is, the half life is inversely proportional to the initial concentration of the reactant A.