Half-Life 1st Order Reaction


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Olivia Young 1A
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Joined: Fri Sep 28, 2018 12:24 am

Half-Life 1st Order Reaction

Postby Olivia Young 1A » Wed Mar 06, 2019 10:44 am

Is the equation t1/2 = 0.693/k valid for all first order reactions? And if so, it it because the initial concentration of A cancel out and leave ln(1/2)?

Dimitri Speron 1C
Posts: 60
Joined: Fri Sep 28, 2018 12:17 am
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Re: Half-Life 1st Order Reaction

Postby Dimitri Speron 1C » Wed Mar 06, 2019 12:39 pm

Yes, that's exactly correct.

Megan_Ervin_1F
Posts: 78
Joined: Fri Sep 28, 2018 12:18 am

Re: Half-Life 1st Order Reaction

Postby Megan_Ervin_1F » Thu Mar 07, 2019 12:19 pm

Also remember that you can always derive this equation it you have any doubts

Erin Kim 2G
Posts: 75
Joined: Fri Sep 28, 2018 12:26 am

Re: Half-Life 1st Order Reaction

Postby Erin Kim 2G » Thu Mar 07, 2019 1:30 pm

For the first order
the half life equation is t(1/2)= ln2/k.
It is applicable to all first order rate reactions.

Annalyn Diaz 1J
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

Re: Half-Life 1st Order Reaction

Postby Annalyn Diaz 1J » Sat Mar 09, 2019 2:50 pm

Why is it that the half-life of a first order reaction doesn't depend on initial concentration?

Nicholas Le 4H
Posts: 74
Joined: Fri Sep 28, 2018 12:24 am

Re: Half-Life 1st Order Reaction

Postby Nicholas Le 4H » Sat Mar 09, 2019 11:14 pm

Yes, it is applicable to all first order rate reactions.

Amy Dinh 1A
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Re: Half-Life 1st Order Reaction

Postby Amy Dinh 1A » Sat Mar 09, 2019 11:21 pm

The initial concentration gets cancelled out when you derive the equation. Thus you end up with the equation t1/2 = 0.693/k


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