5 Steps to a 5 AP Chemistry 2019

374 ❯ SI Units

Temperature

The base unit for temperature in the SI system is kelvin (K).

Celsius to Fahrenheit: °F = (9/5)°C + 32

Fahrenheit to Celsius: °C = (5/9)(°F - 32)

Celsius to kelvin: K = °C + 273.15

Pressure

The unit for pressure in the SI system is the pascal (Pa).

1 millimeter of mercury (mm Hg) = 1 torr

1 Pa = 1 N/m^2 = 1 kg/m s^2

1 atm = 1.01325 × 105 Pa = 760 torr

1 bar = 1 × 105 Pa

Energy

The unit for energy in the SI system is the joule (J).

1 J = 1 kg m^2 /s^2 = 1 coulomb volt

1 calorie (cal) = 4.184 joules (J)

1 food Calorie (Cal) = 1 kilocalorie (kcal) = 4,184 joules (J)

1 British thermal unit (BTU) = 252 calories (cal) = 1,053 joules (J)

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