Page 1 of 1

units of rates and rate constants

Posted: Mon Mar 04, 2019 3:19 pm
by Saachi_Kotia_4E
what are the basic units for rates and rate constants? are they different for different orders?

Re: units of rates and rate constants

Posted: Mon Mar 04, 2019 3:23 pm
by Chem_Mod
Rate of a reaction is generally monitoring the change in concentration over time, thus M/s. For different order reaction, yes rate constants will vary in units, but rate will not.

Re: units of rates and rate constants

Posted: Mon Mar 04, 2019 4:20 pm
by Kirsty Star 2H
For 0 order reactions, the units for k are M/s, for 1st order reactions, the units for k are 1/s, and for 2nd order reactions the units for k are 1/M*s. With M being molarity or concentration

Re: units of rates and rate constants

Posted: Mon Mar 04, 2019 4:40 pm
by Kavvya Gupta 1H
for 0 order reaction, k = mol/Ls. For 1st order, k = 1/s. For 2nd order, k = L/(mol s). Overall the units for a reaction should be mol/Ls

Re: units of rates and rate constants

Posted: Tue Mar 05, 2019 10:03 am
by lindsey_ammann_4E
The above responses are correct. You can think of dividing the units by moles as you move up to the next order.