Rate constant.. please help?

i have been doing this problem for the last few hours and its killing me i cannot figure it out. i set it up correctly but keep getting the wrong answer.

T1 = 286.5K

k1 = 1.35 x 10^4

T2 = 288.5

Ea (activation energy) = 57.2 kJ/mol

R = 8.314 J/K.mol

What is the rate constant at temperature 288.5?

Rate constant.. please help?

Apply Arrhenius Eq:= Ea = -R T ln(K/A)

1st put all the initial values (T1) in above equation then find the value of %26quot;A%26quot; in an equation, Secondly put the final values (T2) and value of %26quot;A%26quot; got earlier, then calculate the ln(k), now %26quot;k2%26quot; i.e. rate constant at temp T2 = 288.5 K can be calculated by k2=e^(values you got for rest of variables/parameters) where %26quot;e%26quot; is Exponential

Rate constant.. please help?

Yep, this can get a little tricky every now and then, but this should help you.

Soln:

k1=1.35 x 10^4

K2= find

Ea= 57.2KJ/mol

T1=286.5K

T2=288.5K

Formula: ln K2/K1 = -Ea/R (1/T2 - 1/T1)

ln K2/1.35 x 10^4 = (-57.2KJ/mol)/(8.314J/mol.k)((1/288.5K - 1/286.5K))(10^3J/1KJ)

ln k2/1.35 x 10^4 = 0.16647

K2= (1.35 x 10^4)( e^0.16647)

K2=(1.35 x 10^4)(1.181128)

Therefore K2= 15945.2 or 1.595 x 10^4 as Answer.

The trick is to change that ln into e, which is just a natural log.

Hope this helps.