Question Detail
Question
Given that Ea for a certain biological reaction is 48 kJ/mol, and that the rate constant is 2.5 × 10⁻² s⁻¹ at 15 °C. What is the rate constant at 37 °C?
Correct Answer
Option A is the correct answer.
Detailed Explanation
Use the two-point Arrhenius equation. T₁ = 15 + 273 = 288 K, T₂ = 37 + 273 = 310 K, Ea = 48,000 J/mol. ln(k₂/k₁) = (48000/8.314)(1/288 - 1/310) = (5773)(0.003472 - 0.003226) = 5773 × 0.000246 = 1.42. k₂/k₁ = e¹·⁴² = 4.14. k₂ = 4.14 × 2.5 × 10⁻² = 0.1035 ≈ 1.0 × 10⁻¹ s⁻¹. (Closest option: C, 1.0 × 10⁻¹ s⁻¹)
Hint
Use the same method as the previous question. Watch the units on Ea.