General Chemistry/Units

SI Fundamental Units These are the seven basic SI units from which all other units are constructed. Quantity Symbol Unit Unit Symbol Length l metre/meter m Time t second s Mass m kilogram kg Thermodynamic temperature T kelvin K Amount of substance n mole mol Electrical current I ampere A Luminous intensity IV candela cd SI Derived Units All other units are derived units. They are built from fundamental units. This is a small selection of units that may be found in General Chemistry. Quantity Symbol Unit Unit Symbol Derived From Force F newton N kg·m·s-2 Energy U joule J kg·m2·s-2 Pressure P pascal Pa kg·m-1·s-2 Power watt W kg·m2·s-3 Electrical charge Q coulomb C A·s Electrical potential V volt V J·C-1 SI Prefixes A prefix appears before a unit's symbol when expressing very large or very small quantities. For example: 0.001 kg = 1 g = 1000 mg. 1000n 10n Prefix Symbol Decimal 10008 1024 yotta Y 1 000 000 000 000 000 000 000 000 10007 1021 zetta Z 1 000 000 000 000 000 000 000 10006 1018 exa E 1 000 000 000 000 000 000 10005 1015 peta P 1 000 000 000 000 000 10004 1012 tera T 1 000 000 000 000 10003 109 giga G 1 000 000 000 10002 106 mega M 1 000 000 10001 103 kilo k 1 000 102 hecto h 100 101 deca da 10 10000 100 (none) (none) 1 10−1 deci d 0.1 10−2 centi c 0.01 1000−1 10−3 milli m 0.001 1000−2 10−6 micro µ 0.000 001 1000−3 10−9 nano n 0.000 000 001 1000−4 10−12 pico p 0.000 000 000 001 1000−5 10−15 femto f 0.000 000 000 000 001 1000−6 10−18 atto a 0.000 000 000 000 000 001 1000−7 10−21 zepto z 0.000 000 000 000 000 000 001 1000−8 10−24 yocto y 0.000 000 000 000 000 000 000 001 Solution Concentration Units Quantity Symbol Units Description Molarity M mol/L moles of solute per liter of solution Molality m mol/kg moles of solute per kilogram of solvent Mole Fraction χ (none) moles of solute per moles of solution Parts per million ppm (none) milligrams of solute per kilogram of solution Parts per billion ppb (none) micrograms of solute per kilogram of solution Other Useful Units Volume Volume Unit Conversion Mass of Water (4 °C) 1 L = 1000 cm3 1 kg 1 cm3 = 1 mL 1 g 1 m3 = 1000 L 1000 kg Pressure Name Symbol Conversion Atmosphere atm = 760 torr = 101.325 kPa Pascal Pa ≈ 7.5 x 10-3 torr Torr (mm Hg) torr ≈ 133.3 Pa Pound-per-square inch psi ≈ 51.7 torr ≈ 6.894 kPa Temperature One degree Celsius is equal to one Kelvin (in magnitude). NameSymbolAbs. ZeroM.P. of WaterB.P. of WaterFahrenheit°F -456.67 °F 32 °F 212 °FCelsius°C -273.15 °C 0 °C 100 °CKelvin K 0 K 273.15 K 373.15 K * Notice it is not "degrees Kelvin".