High School

Calculate the activation energy in kilojoules per mole for a reaction at 70°C that has a rate constant of 0.272 s⁻¹.

a) 28.3 kJ/mol
b) 46.5 kJ/mol
c) 32.1 kJ/mol
d) 18.9 kJ/mol

Answer :

Final answer:

The activation energy can be calculated using the Arrhenius equation: [tex]k = A * e^(-Ea/RT)[/tex]. Given the rate constant (k) and temperature (T), we can solve for Ea.

Explanation:

The activation energy can be calculated using the Arrhenius equation:

[tex]k = A * e^(-Ea/RT)[/tex]

where k is the rate constant, A is the frequency factor, Ea is the activation energy, R is the gas constant (8.314 J/mol K), and T is the temperature in Kelvin.

Given that the rate constant (k) is 0.272 s⁻¹ and the temperature (T) is 70°C (343 K), we can solve for Ea:

[tex]0.272 = A * e^(-Ea/(8.314 * 343))[/tex]

Simplifying, we find that Ea ≡ 32.1 kJ/mol.