Notes on analytical chemistry for students in medicine : extracted from the fifth edition of "Notes for students in chemistry" / by Albert J. Bernays.

  • Bernays, Albert James, 1823-1892.
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: Notes on analytical chemistry for students in medicine : extracted from the fifth edition of "Notes for students in chemistry" / by Albert J. Bernays. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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    THERMOMETERS. Fahrenheit: freezing point 32°, boiling point 212°. F. Centigrade: „ „ 0°, „ „ 100°. C. Beaumur: „ „ 0°, „ „ 80°. E. To convert Fahrenheit into Centigrade and vice versa:— C° x 9 (F°-32°) x 5 = C°. + 32° = F°. MEASUREMENT OF GASES. Boyle and Marriott's law, the volumes of gases are inversely proportional to the pressures. The standard pressure at which gases are measured is 760 millimetres of mercury = 29 • 92 inches. (The old standard, 30 inches, = 7611986 millimetres.) If a gas is measured at any other pressure, a correction must be made, by rule of three, to find what its volume would be at 760 nrillimetres. Similarly a correction must be made for temperature. The standard is 0° C. Gases expand of their volume for every 1° C. increase of temperature: ^3 = '003665. Hence, if a gas be measured at a temperature t°, to find its volume at 0° C. we must divide by 1 + (t° x -003665). Example.—100 c.c. of a gas at 770 m.m. and 10° C.: what is the corrected volume at 0° C. and 760 m.m. ? 1. To correct,for pressure: multiply by the observed pressure in millimetres, and divide by 760. 100 x 770-7-760 = 101-32 c.c. 2. To correct fur temperature : divide by 1 + 003665 t° = (in this case 1-03665). 101-32-rl-03665 = 97-74 c.c. The corrected volume is 97-74 c.c. at 0° and 760 m.m.