Still can't figure this one out-- sorry for reposting, this is the last post, if someone has time to review this question and see if they can figure out how the textbook got 1.0x10^-7 seconds

Iodine combines to form I2 in liquid propane solvent with a constant of 1,5 x 10^10 L/mol. The rate is 2nd order. Since the reaction occurs quickly, a flash of light creates an I concentration of .0100M. How long will it take for 95% of the atoms to form I2?

This must use a second order rate equation, but I cannot get 1.0x10^-7 s which is the answer.

I assume 1.0x10^-7 s = seconds.

A couple of points.

1. Did you mean "occurs quickly, a flash of light creates an I2 concn ......? so that the rate law is rate = k(I)^2 for 2I ==> I2

2. I have been unable to use this to obtain 1.0E-6 but I have close to that.
3. I will look at it again if you will post what you've done. I can't get back for about 2-3 hours from now.