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21.4: Units and Conversion Factors

  • Page ID
    168577
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    Units of Length
    meter (m) = 39.37 inches (in.)
    = 1.094 yards (yd)
    angstrom (Å) = 10–8 cm (exact, definition)
    = 10–10 m (exact, definition)
    centimeter (cm) = 0.01 m (exact, definition) yard (yd) = 0.9144 m
    millimeter (mm) = 0.001 m (exact, definition) inch (in.) = 2.54 cm (exact, definition)
    kilometer (km) = 1000 m (exact, definition) mile (US) = 1.60934 km
    Units of Volume
    liter (L) = 0.001 m3 (exact, definition)
    = 1000 cm3 (exact, definition)
    = 1.057 (US) quarts
    liquid quart (US) = 32 (US) liquid ounces (exact, definition)
    = 0.25 (US) gallon (exact, definition)
    = 0.9463 L
    milliliter (mL) = 0.001 L (exact, definition)
    = 1 cm3 (exact, definition)
    dry quart = 1.1012 L
    microliter (μL) = 10–6 L (exact, definition)
    = 10–3 cm3 (exact, definition)
    cubic foot (US) = 28.316 L
    Units of Mass
    gram (g) = 0.001 kg (exact, definition) ounce (oz) (avoirdupois) = 28.35 g
    milligram (mg) = 0.001 g (exact, definition) pound (lb) (avoirdupois) = 0.4535924 kg
    kilogram (kg) = 1000 g (exact, definition)
    = 2.205 lb
    ton (short) =2000 lb (exact, definition)
    = 907.185 kg
    ton (metric) =1000 kg (exact, definition)
    = 2204.62 lb
    ton (long) = 2240 lb (exact, definition)
    = 1.016 metric ton
    Units of Energy
    4.184 joule (J) = 1 thermochemical calorie (cal)
    1 thermochemical calorie (cal) = 4.184 × 107  erg
    erg = 10–7 J (exact, definition)
    electron-volt (eV) = 1.60218 × 10−19 J = 23.061 kcal mol−1
    liter∙atmosphere = 24.217 cal = 101.325 J (exact, definition)
    nutritional calorie (Cal) = 1000 cal (exact, definition) = 4184 J
    British thermal unit (BTU) = 1054.804 J1
    Units of Pressure
    torr = 1 mm Hg (exact, definition)
    pascal (Pa) = N m–2 (exact, definition)
    = kg m–1 s–2 (exact, definition)
    atmosphere (atm) = 760 mm Hg (exact, definition)
    = 760 torr (exact, definition)
    = 101,325 N m–2 (exact, definition)
    = 101,325 Pa (exact, definition)
    bar = 105 Pa (exact, definition)
    = 105 kg m–1 s–2 (exact, definition)

    Footnotes

    1. 1 BTU is the amount of energy needed to heat one pound of water by one degree Fahrenheit. Therefore, the exact relationship of BTU to joules and other energy units depends on the temperature at which BTU is measured. 59 °F (15 °C) is the most widely used reference temperature for BTU definition in the United States. At this temperature, the conversion factor is the one provided in this table.

    This page titled 21.4: Units and Conversion Factors is shared under a CC BY license and was authored, remixed, and/or curated by OpenStax.

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