Values of the rate constant for the decomposition of N2O5 at four different temperatures are as follows: T(K) k(s^-1) 658 2.14 x 10^5 673 3.23 x 10^5 688 4.81 x 10^5 703 7.03 x 10^5 Determine the activation energy of the decomposition reaction: _____kJ/mol Calculate the value of the rate constant at 300 K. _____s^-1
Temperature k value given are
1) 658 2.14 x 10-5
2) 673 3.23 x1o-5
3) 688 4.81 x 10-5
4) 703 7.03x 10-5
Using the Arhenius equation log(k2/k1) = Ea/R [1/T1 -1/T2]
calculating for different sets 1,2,3 and 4 , we get the valuesfor activation energy like 43858 , 44371, 44088 etc. the average of which can be taken as the activation energy for the reaction .
Thus activation energy = 44105 j = 44.1 kJ /mol
Using the same expression, using the value of Ea already calculated, we can calculate the k at 300K.
log (2.14x 10-5/ k ) = 44105/8.314[1/300 -1/658]
Solving for k we get k = 2.49 x 10-12 M/s
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