T-C4H8

As an example of this type of work. Fig. 1.13 indicates the care with which the initial values of [(CHsCOCHg) + (DMO)]/t/[/-C4H8] were obtained for a range of the mixtures used at 753 K. Typically the ratio was determined over the first 5-10% consumption. As can be seen, the change in the ratio is significant and arises from a complex mechanism often involving secondary formation of products and widely differing rates of removal of the intermediate products. Here, for example, acetone is... 

Plan (a) We must find the concentration of cyclobutane at time t, [C4H8],. The problem tells us this is a first-order reaction, so we use the integrated first-order rate law ... 

Consider a mixture consisting of the isomers C-C4H8, t-C4H8, and the dimer C8Hi6- In order to determine which are the key elements, and the key and nonkey components, we first construct the molecular matrix as... 

Poly(butenes), monoepoxide 119275-53-5 t (C4H8 C4H8 C4Hg) ... 

With ethyl bromide as solvent a brief, exploratory study [77] showed that the rates and DPs were more irreproducible than with other alkyl halides, and this was ascribed, at least partly, to the relatively high dissociation constant of ethyl bromide to ethylene and hydrogen bromide. No evidence was obtained whether ethyl bromide itself is a co-catalyst, and the putative co-catalyst in the reaction was residual water and possibly traces of t-BuBr formed from HBr and isobutene. Experiments with [C4H8] = 0.11-0.92 mole/1, [TiCl4] (2.7-11.2) x 103 mole/1, T = -38° to -103° showed that EDP = 5.5 0.5 kcal/ mole that below about -60° the DP is almost independent of monomer concentration and that kjkp = 2 x 10 4 at -63° and 8 x 10"5 at -71°. 

The technique and apparatus used in this work have been described in detail [81]. The reaction vessel was made hydrophobic by exposure to the vapour of trimethylchlorosilane and evacuated for several hours. Then isobutene, dried by sodium, and methylene dichloride, stored over calcium hydride, were distilled into it, the temperature adjusted, and the reaction started by the breaking of a phial containing a solution of titanium tetrachloride in methylene dichloride and one containing water. These could be broken in this, or the reverse, order, or simultaneously. The ensuing reaction was registered as a time-temperature curve by an automatic recorder. The range of conditions studied was [C4H8] = 0.05 -0.6 mole/1, [TiClJ = (0.1-5) x 10 3 mole/1, [H20] = (0.05-5) x 10 4 mole/1, T= 18°- -95°. 

Takeuchi, K., Yazawa, T., andibusuki, T. Heterogeneous photocatal34ic effect of zinc oxide on photochemical smog formation reaction of C4H8-N02-Air, Atmos. Environ., 17(ll) 2253-2258,1983. 

T (°C) Hi CH4 CiHg C2H4 C3H8 C3H6 C4H10 C4H8 Other CO2 CO References... 

---