Question

The isomerization of cyclopropane follows first order kinetics. The rate constant at 700 K is 6.20 × 10–4 min–1. A.) What is the half-life for this reaction in minutes? B.) If a sealed flask originally contains 0.150 M cyclopropane, what is the concentration remaining after one hour?

Answer 1

Integrated rate equation Kinchies for fast order R: I lu [A). t [AI [AJo = Initial conce (AJ= final K=rate constant t = time when [A] = [AZ t = half life life is In 2[AJ. TAJO K=1 Eye K= 1 x lna Ey, K= 0.693 ty ty 0-693 0-693 6.2ox 10-4 mint 2 1117.1 min = 1117.7 min

B [A] = 0.150 m t = Ihr = 60 min I en 0.150 [A 60x6.20x10-4 = ln 0-150 [A] 0.0372= In 0.150 TAI 6.20x10-4 60 0.0372 e 0-150 TAJ 1.038 = o-150 PAJ [fJ2 0-150 1-038 20.145m