units

[Michaela_Dennis_1K]

Hi, I'm a bit confused on the units for the different order reactions. What units do zero order reactions have? And why are those units correct?

[phiryn]

The unit for k overall is M/S

0 order: M/s
1st order: 1/s
2nd order: 1/M(s)

A trick my TA taught was to start off with M/s and multiply 1/M^to the power of whatever order it is and it cancels out to the above.

Ex. Start with M/S; find 1st order
M/S = 1/M^1
Cancelling out gives 1/S on the left side so thats the units for k

[Denise Mora 1C]

Hi, zero-order reactions have units of M/s. This is because rate has units of molarity per second (M/s) and in zero-order reactions, the rate is directly proportional to the rate constant, therefore rate=k so the units are M/s.