In: Chemistry
A reaction has a rate constant of 1.22×10−4 s−1 at 28 ∘C and 0.229 s−1 at 79 ∘C . What is the value of the rate constant at 16 ∘C ?
The relationship between rate constant and temperature is given by Arrhenium equation given below:
Where, k1 is the rate constant at temperature T1 and k2 is the rate constant at temperature T2.
Ea is the activation energy and R is the constant having value 8.31 J mol-1 K-1.
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First calculate activation energy using rate constants given at two temperatures. Using activation energy calculate rate constant at .
Calculate Ea by substituting k1= 1.22 x 10-4 s-1; T1 = (28+273)K; k2 = 0.229 s-1 and T2 = (79 + 273)K
Therefore, activation energy of given reaction is 130132 J mol-1.
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Calculate, rate constant(k1) at 16 oC using calculated activation energy and Arrhenium equation as follows:
substitute Ea = 130132 J mol-1; T1 = (16+273)K; k2 = 0.229 s-1 and T2 = (79 + 273)K
Therefore, rate constant at is