Abstract
In order to provide the basis for the standardization alcohol-meter at this institute, the investigation of ethanol-table was undertaken two years ago. As the first step, specific-gravity of pure ethanol was determined.
Almost all the published data for specific-gravity of pure ethanol are based on the results of direct measurement of absolute alcohol, but this kind of alcohol is extremely difficult to make. Therefore, the specific-gravity was determined by means of the following methods :
1) Measurement with picnometer of specific-gravity of the sample of nearly pure ethanol.
2) Measurement of the contents of water contained in the sample by Karl-Fischer method.
From these two measurements, a relation was obtained between concentration and specificgravity of nearly pure state of ethanol, and by the extrapolation of this relation the specific-gravity of pure ethanol can be calculated.
Thus, the value 0.78498 was obtained as the specific-gravity at 25°C pure ethanol saturated by air at an ordinary atmospheric pressure. This value is closed to the Osborne's rather than the Gay-Lussac's.
