If the rate constant for the reaction is 1.89 × 10⁴ m⁻¹s⁻¹ at 298 K, what is the rate of the reaction when [NO₂] = 2.61 × 10⁻⁸ m and [O₃] = 1.81 × 10⁻⁷ m? What is the rate of the appearance of NO₃ under these conditions?