284: 



Phelps and Eddy — Hydrobromic Acid. 



(8). In comparing (8) and (9), lengthening the time of action 

 of the alcoholic mixtures, other conditions remaining the same, 

 increases the amount of ethyl benzoate formed. 



In the results in Table (II), where zinc bromide is used as. 

 catalyzer with the hydrobromic acid, no difference was found 

 in the amount of benzoic acid esterihed by the two samples of 

 zinc bromide. It is seen from a comparison of experiments (6) 

 with (10) and (12) with (20) that under definite conditions the 

 greater the concentration of hydrobromic acid with a given 

 amount of zinc bromide present, the greater the amount of 

 benzoic acid esterified. "When these experiments are compared 

 with (1) and (11) of Table I it at once. becomes evident that 

 zinc bromide as well as hydrobromic acid has here a catalytic 

 effect. The ^greater the amount of either catalyzer present 

 the greater the yield under conditions otherwise closely sim- 

 ilar, as is seen in comparing (4), (14) and (24) together, also 

 (2) with (12). The largest amounts of zinc bromide used seem 

 to retard esterification, as appears when (2) and (12) are com- 















Table II. 















Ben- 





Alcohol 





Time of 



Benzoic ester 





zoic 





with HBr 



Tempera- 



action 



, 



>+ 



N 



No. 



acid 



ZnBr 2 



, * V 



ture 





A N 



Theory 



Found 







grm. 



grm. 



cm 3 ; 



3er ct. 





irs. 



mm 



grm. 



grm. 



per ct. 



( K 



) 50 



1-7 



200 



2 



77 



90°-100° 



1 



35 



61*48 



34-78 



56-57 



( 2 ] 



► 50 



1-7 



200 



2 



77 



90° 



1 



50 



61-48 



36-34 



59-19 



( 3 



) 50 



1-7 



200 



2 



77 



100°-150° 



2 



10 



61-48 



25-12 



40-92 



( 4 > 



50 



1-7 



200 



2 



77 



125°-150° 



2 



15 



61-48 



26-15 



42 53 



( 5 



) 50 



1-7 



200 



o 



77 



100° 



2 



25 



61-48 



42 45 



69-04 



( Q ] 



50 



1-7 



200 



2 



77 



90° 



3 



30 



61-48 



44-06 



71-67 



( 7 



50 



1-7 



300 



2 



77 



100° 



3 



5 



61-48 



49-76 



80-93 



( 8 



50 



1-7 



300 



2 



77 



100°-110° 



3 



50 



61-48 



45-05 



73-11 



( 9 



) 50 



1-7 



400 



2 



•77 



100° 



2 



5 



61-48 



48-75 



79-29 



(10, 



) 50 



1-7 



200 27 



74 



85°- 90° 



3 







61-48 



55*28 



89-91 



(lij 



50 



17- 



200 



2 



77 



100° 



1 



30 



61-48 



4636 



75-40 



( 12 



50 



1.7- 



200 



2 



77 



100° 



2 



10 



61-48 



47-46 



7719 



(13 



) 40 



17- 



300 



2 



77 



90°-100° 



4 





61-48 



57-06 



92-81 



(14 



i 50 



17- 



400 



2 



77 



125°-130° 



1 



50 



61 48 



41-46 



67-44 



(15; 



50 



17- 



400 



2 



77 



125°-135° 



2 



30 



61*48 



41 05 



66-77 



(16 



) 50 



17- 



400 



2 



77 



100° 



2 



35 



61-48 



57-05 



92-79 



(17 



) 50 



17- 



400 



2 



•77 



100° 



4 



10 



61-48 



59-74 



97-17 



(18 



) 50 



17- 



400 



2 



77 



125°-130° 



4 



45 



61*48 



45-10 



73-36 



(19 



i 50 



17- 



200 27 



•74 



90°-100° 



1 



50 



61-48 



59*08 



96-09 



(20 



) 50 



17- 



200 27 



74 



100° 



2 



5 



6148 



58-36 



94-96 



(21 



i 50 



17- 



200 27 



•74 



85°- 90° 



3 





61-48 



58-85 



95-72 



(22 



) 50 



42-5 



200 



2 



77 



85°- 9D° 



2 



15 



61*48 



31-56 



51-34 



(23 



50 



425 



200 



2 



77 



100°-110° 



2 



15 



61-48 



41-98 



68-29 



(24; 



50 



42-5 



200 



2 



77 



120°-150° 



2 



-- 



61-48 



44-05 



71-65 



