Gases

Units of Pressure 1atm. = 760mm Hg (torr) = 101,325 pascals (Pa) = kPa = psi

Pressure Barometer – device that measures atmospheric pressure –Invented by Evangelista Torricelli in 1643 Measuring Pressure

Temperature Measured in o C. Must convert to Kelvin. K = o C Standard Temperature & Pressure (STP) = 0 o C and 1atm Volume 1 Liter = 1000ml 1ml = 1cm 3

Boyle’s Law (at constant temp. and amount of gas) P 1 V 1 = P 2 V 2 P = pressure, V = volume

Graphing Boyle’s results Pressure and Volume: Boyle’s Law

Charle’s Law (at constant pressure and amount of gas) V 1 = V 2 T = temperature, V = volume T 1 T 2

Combined Gas Law P 1 V 1 = P 2 V 2 T 1 T 2

Avogadro’s Law V 1 = V 2 n = # of moles of gas n 1 n 2

Dalton’s Law – In a mixture of gases at constant temp. and vol., the total pressure is the sum of the partial pressures. The partial pressure means the pressure the gas would exert if it were by itself. P total = P 1 + P 2 + P 3

Ideal Gas Law PV = nRT Universal gas constant - R = L atm/mol K The molar volume of an ideal gas is 22.4 L at STP L contains 1 mol of an ideal gas at STP.