QUESTION 9 Process the following data then plot the processe
QUESTION 9 Process the following data, then plot the processed data and determine the Ea for this reaction in kj/mol. k, L mol 1s1 302 356 374 410 427 oc 0.00000118 0.00003300 0.00008960 0.00055300 0.00121000
Solution
According to Arrhenius Equation , K = A e -Ea / RT
Where
K = rate constant
T = temperature
R = gas constant = 8.314 J/mol-K
Ea = activation energy
A = Frequency factor (constant)
Rate constant, K = A e - Ea / RT
log K = log A - ( Ea / 2.303RT ) ---(1)
If we take rate constants at two different temperatures, then
log K = log A - ( Ea / 2.303RT ) --- (2)
& log K\' = log A - (Ea / 2.303RT’) ---- (3)
Eq (3 ) - Eq ( 2 ) gives
log ( K\' / K ) = ( Ea / 2.303 R ) x [ ( 1/ T ) - ( 1 / T\' ) ]
Ea = [(2.303R x T x T’) / (T’ - T)] x log (K’ / K)
Given T= 302 oc= 302+273=575 K
T\'= 356 oC= 356+273= 629 K
K= 0.00000118 L mol^-1 s^-1
K\'= 0.00003300 L mol^-1 s^-1
Plug the values we get Ea= 192.6 *10^3 J= 192.6 kJ
