rate equation question (1 Viewer)

[modular]

Simple question

Dinitrogn pentoxide decomposes according to the following eqn at 30 degrees C

2 N2O5 -> 4NO2 + O2

a) write the rate equation for the decomposition
b) calculate the rate constant for the decomp at 30 C (theres a bunch of data for this but if i just know the equation i can work that part out myself)

Cheers for the help

 

[modular]

is it rate = k[n2O5] or rate = k[n2O5]^2 ?

:O

 

[Slidey]

I have no idea what you are talking about. Could you please elaborate and give context?

 

[brenton1987]

Rate of reaction = k[N₂O₅]

 

[xiao1985]

Hmmm, really brenton?
I'm extremely poor in terms of rate of reaction etc, but seems to be that two molecules of N2O5 will need to collide in order for the reaction to proceed?

Or does the decomposition involve two separate steps, and the rate limiting step is the one which involve only 1 mole of N2O5?

 

[brenton1987]

The actual reaction formula is
2 N₂O₅ --> 4 NO₂ + O₂

So 2 molecules are needed for the reaction to proceed.

But kinetically, doubling the concentration of N₂O₅ causes the reaction rate to double. Which makes the decomposition first order for N₂O₅.

The first order rate equation is
Rate of reaction = k[N₂O₅]

Rate equations and reaction equations are share very little in common apart from the species involved.