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At 25 deg C a reaction has rate constant 3.0 * 10⁻⁴ s⁻¹, activation energy 104.4 kJ mol⁻¹, and Arrhenius pre-exponential factor A = 6.0 * 10¹⁴ s⁻¹. What is the value of the rate constant as T -> infinity?

1. 2.0 * 10¹⁸ s⁻¹
2. 6.0 * 10¹⁴ s⁻¹
3. infinity
4. 3.6 * 10³⁰ s⁻¹

Correct answer: 6.0 * 10¹⁴ s⁻¹

Solution

In k = A e^(-Ea/RT), as T -> infinity the exponent -Ea/RT -> 0, so e⁰ = 1 and k -> A = 6.0 * 10¹⁴ s⁻¹.

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