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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: o0CY0o on April 13, 2009, 02:20:14 PM

Title: Questions on activation energy
Post by: o0CY0o on April 13, 2009, 02:20:14 PM
Rate constants for the gas-phase decomposition of hydrogen iodide, 2HI(g) → H2(g) + I2(g),
are listed in the following table :
T/°C 283 356 393 427 508
k/mol-1 s-1 3.52 x 10-7 3.02 x 10-5 2.19 x 10-4 1.16 x 10-3 3.95 x 10-2
(a) Find the activation energy (in kJ mol-1) using all five data points.

i've been trying to use the arrhenius equation and also all the equations i know. however, it seems that i cannot work it out.
i think it is sth to do with the inital rate. i'm thinking of the fifth data minusing the 1st one. can anyone give me some hints?
Title: Re: Questions on activation energy
Post by: Yggdrasil on April 13, 2009, 05:24:08 PM
When you're trying to fit with the Arrhenius Eq, did you remember to convert the temperature to kelvin?
Title: Re: Questions on activation energy
Post by: o0CY0o on April 14, 2009, 12:42:02 AM
surely did ;)