[neon flash!]

need help with the following question:
1) determine the units of k if rate = k [A]^1/2 [ B]
the overall order of reaction is 1/2 +1 = 3/2
my lecurer said something about the units being M^(n-1) s-1 where n is the overall order of reaction.
which would make the units of k M^1/2 s-1
but elsewhere in my notes i've got written M^-1/2 s-1

so i'm not sure if the fomula is M^-(n-1) s-1 or M^(n-1) s-1

is anyone able to confirm if either of these are correct? if so which one?

[juanrga]

need help with the following question:
1) determine the units of k if rate = k [A]^1/2 [ B]
the overall order of reaction is 1/2 +1 = 3/2
my lecurer said something about the units being M^(n-1) s-1 where n is the overall order of reaction.
which would make the units of k M^1/2 s-1
but elsewhere in my notes i've got written M^-1/2 s-1

so i'm not sure if the fomula is M^-(n-1) s-1 or M^(n-1) s-1

is anyone able to confirm if either of these are correct? if so which one?

Forget the right-hand side (k [A]^1/2 [ B]) and write the definition for the "rate" of any reaction. What do you think are the units of the definition?

[neon flash!]

M s-1

[juanrga]

M s-1

Right, now use the equation: rate = k [A]^1/2 [ B]

M s^-1 = k M^1/2 M

From here you can obtain the units of k directly for this specific case.

Or if you prefer, you can solve your question about what is the formula for the overall order n for any case

M s^-1 = k Mⁿ

is is M^-(n-1) s^-1 or M^(n-1) s^-1?

My general advice is that instead of remembering formulae, it is best if you can derive the formulae when you need to use it  .

[neon flash!]

(1-n)

!?

thxanks! :-]