cancel Log out
settings Settings

# Measurement

By Levi Clancy for Student Reader on
updated

▶︎ View related▼︎ Tap to hide

## Units of Mass

Atomic Mass Unit 1 u = 1.6605 × 10-27 One mole is defined as the amount of substance that contains exactly as many atoms or molecules as are in precisely 12 grams of 12C.units in moles = mass ( grams ) / molecular mass ( g mol-1 )

## Units of Temperature

Celsius/Centigrade (C) Absolute zero: -273.15°CWater freezes: 0°CWater boils: 100°CT°C = 5⁄9 ( T°F - 32 ) Absolute zero: -459.67°FWater freezes: 32°FWater boils: 212°FT°F = 9⁄5 T°C + 32 Kelvin and Centigrade have equal increments. The difference between Kelvin and Centigrade is that 0°K is absolute zero (-273.15°C) and 0°C is the freezing point of water (273.15°K). Thus, ΔT in °K and °C will be equal, even though T°F ≠ T°C.Absolute zero: 0°KWater freezes: 273.15°KWater boils: 373.15°K

## Units of Pressure

Pascals (Pa) Torr N/m2 1 Pascal = 7.50247 · 10-3 mm-Hg1 Pascal = 9.86923 · 10-6 atm1 Pascal = 10-5 Bar1 Pascal = 1.45037738 · 10-4 PSI mm-Hg 1 Torr = 133.289437 Pascal 1 atm = 1.01325 · 105 Pascal1 atm = 760.0 mm-Hg 1 Bar = 105 Pascal lbs in-2 1 PSI = 6894.75729 Pascal

## Units of Heat and Energy

Joule (J) 1 calorie = 4.186 J 1 Calorie = 4.186 kJ = 1000 cal = 1 kcal = 4186 J