# Determining rate constant and reaction order

1. Apr 22, 2010

### Aeon

1. The problem statement, all variables and given/known data

CH3OCH3(g) ---> CH4(g) + H2(g) + CO(g)

The reaction is conducted at 777.15 K, at constant volume beginning with pure ether.

Code (Text):
t(hours)  0    390  777  1195  3155  +inf
P (torr) 312   408  488  562    779   931
Determine the order of the reaction and approximate the rate constant.

2. Relevant equations

1) PV = nRT

3. The attempt at a solution

I know I need a number of moles. Pressure is related to moles as stated by equation 1.
Unless I assign an arbitrary value to V, I cannot calculate a value for n.

I have written this table:

Code (Text):
A --------------> 3B
t=0             a                   0
t              a-x                +3x
t=+inf         0                   3a
I know I have to convert P(tot) in P(ether) using:

P(tot) = (nA + nB) RT/V and
P(ether) = nA RT/V

But erm....
major brainfreeze. (as is usually the case when trying to study after a big meal lol!)

2. Apr 22, 2010

### Aeon

bump

I'm done with the rest of my HW. For some reason I can't get my head around this one (and another similar problem).

Can someone help me solve this problem? Please.

Thanks,
Aeon.