The Baumé scale is a measure of a solution's specific gravity, not its concentration. To get the molarity of the HCl, you'll have to convert degrees Baumé to a specific gravity, and then use the specific gravity to look up the concentration of HCl from a table in a handbook. For example, the CRC handbook has tables that relate specific gravities to concentrations for sulfuric acid.
|Pure water||15 (w/w)% NaCl|
|Calibration of a heavier-than-water|
hydrometer on the Baumé scale.
At 60°F, specific gravity can be calculated from degrees Baumé using the following formulas:
|liquids lighter than water:||sp. gr. = 140/(°Bé + 130)|
|liquids heavier than water:||sp. gr. = 145/(145 - °Bé)|
Although the Baumé scale is almost never mentioned in chemistry courses, tradesmen often use it as a convenient way to check solution concentration. For example, U. S. Grade A honey must have a Baumé reading of at least 42.49°Bé at 60°F. Recipes for lowering the pH of pool water call for 20°Bé hydrochloric acid. It's also used by brewers for checking the density of sugar solutions before fermentation.
|This quintessential handbook contains data for about 2500 inorganic compounds and 12000 organic compounds. Relevant physical properties listed include crystal structure, color, solubility, melting points, boiling points, heats of formation, heats of vaporization, heats of fusion, entropies, heat capacities, critical pressure and temperature, vapor pressure, and optical properties. (Book/CDROM; no Web access). |
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Last Revised 02/15/10.URL: http://antoine.frostburg.edu/chem/senese/101/measurement/faq/print-baume-scale.shtml