Units

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Jessica Chen 2C
Posts: 103
Joined: Thu Jul 11, 2019 12:17 am

Units

Postby Jessica Chen 2C » Wed Mar 11, 2020 10:57 am

I just want to confirm because I was a bit confused: the units for rate are always the same, but units for rate constants can change depending on the order of the reaction?

Sanjana Munagala_1j
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Re: Units

Postby Sanjana Munagala_1j » Wed Mar 11, 2020 11:00 am

That is correct. The units of rate will always be concentration over time and the rate constant will differ based on the order so that units align on both sides of the equation.

Hope that helps!

005391550
Posts: 103
Joined: Thu Jul 25, 2019 12:15 am

Re: Units

Postby 005391550 » Wed Mar 11, 2020 11:13 am

the units for rate will always be M/s while rate constant can be M/w (0 order), 1/s (first order), or 1/Ms (second order)

BNgo_2L
Posts: 95
Joined: Wed Sep 11, 2019 12:17 am

Re: Units

Postby BNgo_2L » Thu Mar 12, 2020 8:00 am

You can determine the unit of the rate constants for each order reaction by using the rate laws to derive k.
(ex. second-order: mol/L s = k [mol/L][mol/L] --> k = L/mol s)

Rebekah Alfred 1J
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Re: Units

Postby Rebekah Alfred 1J » Thu Mar 12, 2020 8:09 am

As this visual shows, the units for the rate constant change, but the units for the rate remain the same.
Image

Leonardo Le Merle 1D
Posts: 56
Joined: Wed Feb 27, 2019 12:16 am

Re: Units

Postby Leonardo Le Merle 1D » Thu Mar 12, 2020 11:00 am

The above post also applies for third order reactions; M would be squared in the denominator.

Tanmay Singhal 1H
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Joined: Sat Jul 20, 2019 12:16 am

Re: Units

Postby Tanmay Singhal 1H » Thu Mar 12, 2020 11:11 am

yes. a good way to determine it is one of the first homework problems in 7A

Jasmine W 1K
Posts: 49
Joined: Sat Sep 07, 2019 12:18 am

Re: Units

Postby Jasmine W 1K » Thu Mar 12, 2020 6:47 pm

yes. the units for rate is always concentration (M) over time (s)

Juliana Chopelas 1A
Posts: 50
Joined: Sat Aug 24, 2019 12:16 am

Re: Units

Postby Juliana Chopelas 1A » Sat Mar 14, 2020 10:29 am

the units for rate constant will change depending on the order of the reaction but the units for rate is the same


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