The rate law for the reaction in which 1 mol of cyclobutane (C₄H₈) decomposes to 2 mol of ethylene (C₂H₄) at 1273 K is Rate = (87 s⁻¹) [C₄H₈]. What is the instantaneous rate of this reaction when [C₄H₈] = 0.200 mol/L?