Gas Laws Why does a gas station sell liquid fuel?

Values and preferred units P—atmospheres T—kelvins V—Liters n—moles

Conversions P:1 atm=760 mmHg=760torr =101.3 kPa=101,325 Pa T:T(k) = T( o C) V: 1L=1000 ml=.001 m 3

Convert! 25 o C=_______k 0 o C=_______k 100 o C=_______k 98k=_______ o C 417k=_______ o C 1809k=_______ o C

Convert! 633 mmHg = ___________ atm 724 mmHg = ___________ atm.83 atm = ___________mmHg.95 atm = ___________mmHg 87 kPa = ___________ atm 122 kPa = ___________ mmHg

Boyle’s Law Pressure & volume are inversely related PV=k P 1 V 1 =P 2 V 2 When the pressure goes up, volume goes down. P V At a constant temperature!

State it! If you double the pressure, you __________ the volume. If you reduce the pressure to 1/3 of the original, you __________ the volume. If you double the volume, you __________ the pressure. If you increase the pressure 20 times, you __________ the volume

For example: If a sample of air has a volume of 120 ml at a pressure of 2.0 atm, what will its volume be if the pressure is increased to 4.0 atm?

For example: If a sample of helium has a volume of 433 ml at a pressure of 88 kPa, what will its volume be if the pressure is increased to 2.8 atm?

Charles’ Law Temperature & volume are directly related V/T=k V 1 /T 1 =V 2 /T 2 When the temperature goes up, volume goes up. T V At a constant pressure!

Charles’ Law Temperature & volume are directly related V/T=k V 1 /T 1 =V 2 /T 2 When the temperature goes up, volume goes up. T V At a constant pressure! Is it hot in here?

Charles’ Law Temperature & volume are directly related V/T=k V 1 /T 1 =V 2 /T 2 When the temperature goes up, volume goes up. T V At a constant pressure! You must use absolute temperatures

For example: If a sample of oxygen has a volume of 2.4 m 3 at 19 o C, what will its volume be if the temperature is increased to 155 o C?

For example: If a sample of chlorine has a volume of 12 L at 38 o C, at what temperature will its volume be 17 L?

Gay-Lussac’s Law Temperature & pressure are directly related P/T=k P 1 /T 1 =P 2 /T 2 When the temperature goes up, pressure goes up. T P At a constant volume!

For example: A tire is fairly flat (P=1200 mmHg) at -5 o C on a cold morning. At what temperature would it reach its normal 3.5 atmospheres if you were to heat it up instead of pumping more air in?

Avogadro’s Law Volume & # of particles are directly related V/n=k V 1 /n 1 =V 2 /n 2 When the number of particles goes up, volume goes up. n V At a constant pressure and temperature!

For example: N 2 (g) + 3H 2 (g)  2NH 3 (g) If 30 L N 2 and 90L of H 2 are mixed, what would the final volume be if all of the reactants formed ammonia (at constant pressure and temperature)?

Combined Gas Law Pressure, volume & temperature relationship PV/T=k P 1 V 1 /T 1 =P 2 V 2 /T 2

For example: If a sample of hydrogen has a volume of 56 ml at STP, what will its volume be 19 o C and.84 atm?

For example: If a sample of hydrogen has a volume of 56 ml at STP, what will its volume be 19 o C and.84 atm? STP=standard temperature and pressure = 273k, 1.00 atm

P.S. The standard molar volume for an ideal gas is: at STP 22.4L/mol

P.S. is about 22.4 L

P 1 V 1 =P 2 V 2 V 1 /T 1 =V 2 /T 2 V 1 /n 1 =V 2 /n 2

P1V1n1T1P1V1n1T1 = P2V2n2T2P2V2n2T2 always, for any sample of gas. What is ? P1V1n1T1P1V1n1T1

P1V1n1T1P1V1n1T1 The molar volume of a gas is 22.4 L at STP 1.00 mol273 k 22.4 L 1.00 atm

Ideal Gas Law Pressure, volume, temperature & mole relationship PV/nT=R P 1 V 1 /n 1 T 1 =P 2 V 2 /n 2 T 2 =R PV=nRT Ideal Gas constant.0821 L atm/mol k An ideal gas has particles of zero volume, with no attraction to each other! It doesn’t even matter which gas is there

Ideally… A?38 ml.12 mol58 o C B725 mmHg ?4.9 mol198 o C C325 kPa.29 m 3 ?457 k D1.2 atm9.1 L.85 mol?