edited by JOHNH. WOTlZ Southern Illinois Universitv Carbondale, lllinols 62901
Aoru behind the Aoru J
coefficient o f t h e saponil'ication reaction. A specimen ol'his second~orderrate constants, for aqueous solutions originally 0.02 M on 110th sodium hydroxide and ethyl acetate at 20.5-2(l.fiDC, is helow 19). T h e reactim was tldlowed to more than 'is? completion.
R. B. Warder and the Kinetics of Saponification D. S. Tarbell and A. T. Tarbell Vanderbilt University Nashville. TN 37235
Secand-order rate constantd
Time lminl
T h e rapid growth of physical organic chemistry in this country following World War I, particularlv in the lahorat~~ries of J. B. Conant, I.. 1'. Hammett, C. R. Hauser, M. S. Kharasrh. H. J. Lucas and their scientific rmrenv, has tended t o ihscnre t h e earlier significant accrnnplishments in this field hefore 1914. bv S. F. Acree, .J. LJ. Nef, E,F:. Reid, J . F. Nurris, Julius stiegli&, Arthur Michael and others. This note rlest:ril~esthe first demonstration of the second-order kinetics of the saponification of a n ester. hy K. B. Warder at the liniversityof Cincinnati in 1881 ( 1 I. Warder's priority is acknowledged in Nernst's texhook, although his name does not al,lmx in Partington's compilation on the history of chemistry (21. Robert Bowne Warder 11848-1905) was the son o l a successful physician, horticulturalist and lorester. Dr. John Astrm Warder (31,who settled near Cincinnati. Rohert Warder (A. B. Earlham, 1866), taught a t the LJniversity of Illinois ithen t h e Illinois Industrial Universitvl for two vram. took a H.S. a t Harvard in 1874, and spent a year in (iermany. some if it with Hofmann at Berlin. C. Loring .Jackson of' Harvard, whu was being introduced to research there hy Hofmann, influenced Warder by his example. Warder in addition to some research activity observed carefully the (:erman methrds of teaching chemistry. He ohtained a good grounding in physical chemistry. Warder was on the staff a t the Ilniversity of Cincinnati with Professor F. W. Clarke from 18i.5-79, then taught hriefly at Purdue and Haverford. His lifelong attachment t o the Society of Friends and his sense ofnuhlic service led him to teach at Howard University in Washington, D.C., from I887 until his earlvdeath in 1905 ( 4 ) .His interest in Howard Universitv. may have been amused by his Cincinnati colleague, Clarke. who taught a t Howard University in 18i:q-i4 and located in Washington as Chief Chemist on the L1.S. (>edogiral Survey in 1883 (5). Warder's scientific publications, a l t h m g h n d numerrws. reveal a n intelligent, versatile mind, with active interests in several fields of physics and chemistry, and a critical analytical view of current work. His research on the kinetics ofethvl acetate sa~xn~ification by aqueous alkali was carefully done hy titration procedures which he had thoroughly worked out. He I'irst descrihed a serviceable method for titration of strong alkali in the presence of carbonate (61, which with some modification ( 7 ) was still being referred t o in texts on analytical chemistry manvdecades later (XI. He then showed t h a t the reactim ~
CHaCOOrzHs t NaOH
On the temperature ruefficient of the reaction. Warder stated (10)
In the next rew years, a numher of European chemisb, van't Hoff, Ostwald, Arrhenius and others, did more exhaustive kinetic studies on this reaction ( I 1 ), hut Warder was the pioneer. His later puhlir.ations included, in addition La some analyt ical work, critiques of papers on reaction kinetics of organic and inorganic reactions (12). Significant of' these was an a t tempt t o derive a kinetic scheme for the data of D. M. 1.ichty of Michigan un t h e rates ofesterification uf halogenated aliphatic acids I I:$). This was a case o f a reversible secund order reaction, lor which Warder n ~ u l dnot derive satisfactory rate r drift in rate constants (1-1).Several plausible reasons f ~ the constants were prapmed hy Warder and hy the ahstracter, Ostwald. It is not clear that Warder ever calculated Arrhenius activation enereies. hut his nosition as a n earlv serious student of chemical kinetics deserves notice. Literature Cited \ Y o r d w K H . HI.,. Id. l i R I
i I X Y I I . A m ( I l m .I .?.i?ii(lXR1-21:thelatterpaper is mucli rnr,roextenrirp a n d d ~ 1 ~ ~Iicd, 1 ~ ~/~apers t i state that the work WBI dsm? a! I h r I n i v c ~ r s ~ ,ti uf rin~lnnnti l i i Kemrt, \lnlfer. " ' l ' h ~ i r a ~ r i( ~ ' hlr m # n r i . " r e i t 4 hy H 7'l'ward h m thefith German r,I, hln~mlli~in. 1911.1,. ilili.I'aninel,n..l It.. " A Hirfllr~ill~h~mirfn.:'Macmillan. I I,,",\' ,%d.
Ill
,,,,,,
,,
- CH:,COONa + C2H50H
gave good rate constan1.s for the second-order k i n ~ t i equar tion rate
=
k[NaOH][esterl
He measured the second order rate constants at 20 temperatures from M ° C . t o X7.ioC.. and although the Arrhenius equation for calculating activation energies was pmpmed only in 1889, Warder furnished accurate data for the temperature
1 1 I I N ~ r n r l r, a i u i c r ~ rl l i . 02,
\ v n m p r . ~ . ~ ~ iiilni . . ~ o i. I . ~
~ , X ~ I ~ R ! ~ I : S ~ ~ I ~ , , ~ ~ . Hrhl.m . , ~ ~ ~ W ~ ~ ~ ~
. I i?.:ili i X ! 4 i l : \ V i ~ n l ~ ~Itr . H . A m rhrn d . lX.2:1 11896, (1:4 I.~~htv,~l. !&An, l'hq,,>$ .I, t#,>!4
