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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: sodium.dioxid on May 10, 2012, 11:39:31 PM

Title: Are SN1 reactions similar to exponential decay
Post by: sodium.dioxid on May 10, 2012, 11:39:31 PM

Do they undergo a constant half-life? Is half-life even applicable to them?

Title: Re: Are SN1 reactions similar to exponential decay
Post by: ramboacid on May 11, 2012, 12:17:16 AM

S_N1 reactions are first order, just like exponential decay reactions. Does that help?

I don't see why you can't have a half life for any reaction, though it may be awkward to think about at first because it is usually discussed with exponential decay.

Title: Re: Are SN1 reactions similar to exponential decay
Post by: sodium.dioxid on May 11, 2012, 12:24:00 AM

Quote from: ramboacid on May 11, 2012, 12:17:16 AM

S_N1 reactions are first order, just like exponential decay reactions. Does that help?

So, by default, you are saying that the half life of SN1 is constant.

Title: Re: Are SN1 reactions similar to exponential decay
Post by: ramboacid on May 11, 2012, 01:03:50 AM

That's what I would think. :-\ What I've heard is that any 1^st order reaction has a half-life of [itex]t_{1/2} = \frac{\ln{(2)}}{k}[/itex], where k is the rate constant. So I guess it applies to S_N1 as well.

Title: Re: Are SN1 reactions similar to exponential decay
Post by: sodium.dioxid on May 11, 2012, 01:08:59 AM

Quote from: ramboacid on May 11, 2012, 01:03:50 AM

That's what I would think. :-\ What I've heard is that any 1^st order reaction has a half-life of [itex]t_{1/2} = \frac{\ln{(2)}}{k}[/itex], where k is the rate constant. So I guess it applies to S_N1 as well.

I was thinking the same thing here.