Question

SF4 ---> SF2 + F2

rate constant (k) = .011 l/molxS [SF4]2

How many minutes will it take for the concentration of SF4 to be reduced from 2.5 M to .25 M?

I said this was a 2nd order reaction and used :
(1/final)= kt + (1/initial) and solved for t.

the answer should be 5.5. I am not getting that answer. what am I doing wrong?

Answer 1

That is correct but if they want the answer in minutes you have to divide by 60. that equation gives you the (seconds) that it will take. when you divide by 60 it will give you the minutes.

1/.25M=.011(t)+1/2.5M
subtract (1/2.5) from both sides
3.6=.011(t)
divide both sides by .011
t=327.27s
they ask for minutes so divide this number by 60
t=327.27/60 t=5.45 or 5.5