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

The rate of teaction

O(g) + NO2(g) --> NO(g) +O2(g)

was studied at a certain temperature.

NO2 is in a large excess at 1.0x10^13 molecules/cm^3

Data:

Time............................[O](atoms/cm^3)

0.................................5.0x10^9

1.0X10^-2....................1.9X10^9

2.0X10^-2.....................6.8X10^8

3.0X10^2......................2.5^10^8

The reaction rate is know to be first order with respect to NO2. Determine the overall rate law and value of rate law constant

**2. Relevant equations**

k[A]

**=rate**

Ok I know that a O is a first order rate so the overall rate law is k[O][NO2]=Rate. The slope of ln[O] vs t is 99.8. So now how do you find the constant?

I think its k(1.0x10^13)(5.0x10^9)=99.8

so k= 2.0x10^-21 cm^3/atoms * s ,but something doesn't seem right about it

**3. The attempt at a solution**Ok I know that a O is a first order rate so the overall rate law is k[O][NO2]=Rate. The slope of ln[O] vs t is 99.8. So now how do you find the constant?

I think its k(1.0x10^13)(5.0x10^9)=99.8

so k= 2.0x10^-21 cm^3/atoms * s ,but something doesn't seem right about it