CH ENGR 100 Lecture 10: [Wk5.Th] Multi-Phase Systems

AAROL IN CH2720 FALL 2018 ed dehydration reaction of alcohol in lecture. In today's experiment we will perform this cyclohexanol, a secondary alcohol commonly used in laboratory and industry. The overall picted in Scheme 1 here below: он acid +H2O acid H2SO4, H3P04, TsOH, etc. Scheme 1. Dehydration of Cyclohexanol Catalyzed by Strong Acid on of alcohol occurs via a multi-step reaction mechanism: Firstly, the oxygen in alcoho up is protonated by an acid catalyst to form a good leaving group (-O'H2). After this initia ction, the now activated reactant can undergo E1 elimination through a key carbocatio Then a general base (e.g. the solvent) will carry out a second acid and base reaction (th f El elimination) to remove a B-hydrogen and produce the t bond in the alkene produc rate the acid catalyst. ntal setun widely used in organic labs, the

4) Hydrogen sulfide H2S is a volatile acid that equilibrates, in closed systems, with aqueous solutions according to the reaction: For a gaseous phase containing H2Sn equilibrium with water, in a closed vessel, calculate a) The Henry's law constant, KH, for H2S. Note that KH= Keq for the two phase conecntraion n wre of lHISp water it concentration in water is CTS_ [H2S(aq)]+[HS]+[$4, is 1-10% M and the solution pH is 8.5. The dissociation reactions of H2S) n the water phase are partitioning reaction given above. b) The partial pressure of H2Sg) overlying the water if the total soluble sulfide described by Kax ka2