10 The Philippine Journal of Science 1922 
COMPARISON OF HYDROCHLORIC ACID WITH SULPHURIC ACID 
AS CATALYST . 
Strong sulphuric acid has a tendency to form addition prod- 
ucts with unsaturated compounds, and is known to react with 
chaulmoogra oil. In order to ascertain whether such undesir- 
able action takes place under the conditions which we use for 
the esterification, experiments have been conducted comparing 
the sulphuric acid catalysis with that of hydrochloric acid, 
which does not have a similar combining power. The results 
of typical parallel experiments are shown in Table 1. In this 
’ ease 1 liter of 95 per cent sulphuric acid instead of the usual 
750 cubic centimeters of 93 per cent was employed as catalyst, 
and boiling was continued for forty-one hours to intensify the 
effect. The control experiment was done in the same manner, 
but instead of adding sulphuric acid dry hydrochloric acid gas 
was passed into the alcohol until it showed 5 per cent by titra- 
tion. Thirteen liters of 96 per cent alcohol and 10 kilograms 
of oil were used in each experiment. The oil was presumably 
pure Taraktogenos, being guaranteed by the maker, P. K. Sen, 
of Chittagong. 
TABLE 1.—Comparison of hydrochloric acid with sulphuric acid as catalyst. 
moogra Bate weebed with - Distilled enter: 
Catalyst osc. ogo ce et é HCl HeSO4 HCl HeSO4 
Bpecifie gravity 80/49 Goes a es ee 0. 890 0.891 
Refractive index 80° C. Dline_______.____.____ 1. 4767 1. 4575 1, 4570 1.4568 1.4566 
Optical rotation, D, 100 mm oi 46.0 40 38 38.1 38.9 
Iodine No., Hanus _._........--..-------...--..| 102 _ 98 94 97.5 | 9 
Saponification No.2.) 198 187 190 187 188 
Acidity, as-per cent oleie 22000 18.8 4.4 2.1 1.38 0.51 
Freezing point of fatty acids, °C_._____._____. 29 29 30 30 31 
Specific rotatory power of fatty acids dis- 
BOlVOd Ii S7IONG pcs cidseced. sscsas. exer ac SET 46.8 47.3 45.5 45.5 
The data given in Table 1 show that sulphuric acid, under 
the given conditions, does not appreciably change the chaul- 
moogra fatty acids. The figures for the rotation of the washed 
esters are approximate, as they were too dark for accurate 
determination. The optical rotation of the hydrochloric acid 
esters decreased somewhat upon distillation. This decrease has 
been noted to occur when distillation is delayed by accidental 
difficulty with the vacuum, which happened in this run. The 
