Studies with a Single-Pulse Shock Tube. I. The Cis—Trans Isomerization of Butene-2

Abstract

The cis—trans isomerization of butene‐2 was investigated behind reflected shocks in a single‐pulse shock tube of a novel design. The temperature range covered was 1000°—1250°K, and concentrations of 1% and 6% of the butene in argon were used. Analyses were made by vapor‐phase chromatography. The first‐order rate constants obtained in this work fall slightly above the extrapolated Arrhenius curves of two recent low‐temperature studies. An activation energy of 65, rather than 62.8 kcal/mole, is obtained when a straight line is drawn between the high and the low temperature data. |The rate constant obtained is $$k_{\mathrm{cis}}^{\infty }{\text{=3.5×10}}^{14}\exp {\text{(−65×10}}^3\mathrm{/RT).}$$ Possible sources of errors in evaluating reaction times in the single‐pulse shock tube are discussed.