Problem: A reaction has a rate constant k = 8.54 x 10-4 s-1 at 45 °C and an activation energy, Ea = 90.8 kJ. What is the value of k at 25 °C?A. 8.52 x 10-4 s-1 B. 4.46 x 10-3 s-1C. 8.54 x 10-5 s-1D. 4.46 x 10-4 s-1E. 8.54 x 10-3 s-1

FREE Expert Solution

We’re being asked to determine the rate constant at 25°C of the reaction when k = 8.54 x 10-4 s -1 at 45°C with a EA = 90.8 kJ


This means we need to use the two-point form of the Arrhenius Equation:


lnk2k1 = -EaR1T2-1T1


where:

k1 = rate constant at T1 

k2 = rate constant at T

Ea = activation energy (in J/mol) 

R = gas constant (8.314 J/mol•K) 

T1 and T2 = temperature (in K).

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Problem Details

A reaction has a rate constant k = 8.54 x 10-4 s-1 at 45 °C and an activation energy, Ea = 90.8 kJ. What is the value of k at 25 °C?

A. 8.52 x 10-4 s-1 

B. 4.46 x 10-3 s-1

C. 8.54 x 10-5 s-1

D. 4.46 x 10-4 s-1

E. 8.54 x 10-3 s-1

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