# How do I determine the units of the rate constant for a zero order, first order, second order, and third order reaction?

##### 1 Answer

Jun 12, 2017

You will need to be able to write a general rate law and solve for the units...

#r(t) = k[A]^n#

#r(t)# is the initial rate as a function of time#t# ,#k# is the rate constant,#[A]# is the concentration of#A# , and#n# is the order of#A# .

Since

#"M"/"s" = [???] cdot "M"^n#

#=> [???]#

#=# #color(blue)("units of rate constant in general")#

#= color(blue)("M"^(1 - n)/"s")#

So,

- zero order should simply be
#"M"^(1 - 0)/"s" = "M/s"# . - first order should be
#"M"^(1 - 1)/"s" = 1/"s"# .

Can you work out second order and third order?