Chemistry
posted by Odesa on .
N2O5 dissolved in CCl4 decomposes to give N2O4 and O2. The reaction is first order with a halflife of 1234 seconds. How long will it take, in seconds, for the concentration of N2O5 to fall to 1.1% of its initial value?

k = 0.693/t_{1/2}
ln(No/N) = kt
Use No = 100 (you can choose any number)
N = 100 x 0.011 = ?
k from above.
t = solve for this. 
DrBob222 explain better please

So what is it? or how to guide in filling in the date in the equation?

Thank you DrBob222,
the fraction left after t seconds is (1/2)^(t/1234)
(1/2)^(t/1234) = 0.011
t = 8028.84