Bell Ringer What is the difference between the different states of matter? [in terms of energy or particles]

Kinetic Molecular Theory

The Kinetic Molecular Theory based on the idea that particles are constantly moving can be applied to solid, liquid, or gas provides a model of ideal gas behavior so it is only an approximation Ideal student Real student vs

1. Gases consist of tiny particles that are very far apart most volume is empty spacelow density allows gases to be easily compressed 2. All collisions between particles and container walls are elastic there is no net loss of energy when particles collide total kinetic energy stays constant even though it can be transferred between particles

3. Particles are in continuous, rapid, random motion since they are moving, they have KE KE overcomes their attractive forces 4. No forces of attraction or repulsion YOU ARE ATTRACTED TO EVERYTHING!

Average kinetic energy depends on temperature KE increases as temperature increases At the same T, lighter particles have higher speeds than heavier ones velocity and temperature are directly proportional

REAL Gases vs. IDEAL Gases The most ideal real gases are H and He ideal gas is defined by the KMT most gases behave close to the ideal when there is: HIGH temperature – so they have enough KE to overcome attractive forces Low pressure – so they are very spread out Gases with little attraction, low mass, are more ideal (monatomic gases) The most ideal real gases are H and He

Activity Create a cartoon that helps to explain the KMT to other students! Grade will be based upon: Creativity Effort Use of color

List the 4 parts of the KMT. Bell Ringer List the 4 parts of the KMT.

Pressure

Pressure P : amount of force in an area Why would shoes with smaller diameter heel not be allowed on gym floor? As surface area decreases, pressure increases Pressure exerted by a gas depends on volume temperature number of molecules

STANDARD TEMPERATURE & PRESSURE STP Standard Temperature = 0°C Standard Pressure = 1 atm

Pressure and Temperature STP (Standard Temperature and Pressure) standard temperature standard pressure 0oC 1 atm 273 K 101.3 kPa 760 mm Hg Equations / Conversion Factors: K = oC + 273 oC = K – 273 1 atm = 101.3 kPa = 760 mm Hg = 760 torr

Conversions Convert 25oC to Kelvin. K = oC + 273 25oC + 273 = 298 K How many kPa is 1.37 atm? 101.3 kPa X kPa = 1.37 atm = 138.8 kPa 1 atm How many mm Hg is 231.5 kPa? 760 mm Hg X mm Hg = 231.5 kPa = 1737 mm Hg 101.3 kPa

Practice Conversions

Vapor Pressure Is the pressure of the vapor over a liquid (and some solids) at equilibrium Must be in contact with a liquid otherwise you just have a gas! Depends on temperature only

NOT all liquids have same vapor pressure at same temp. measure of the tendency for liquid particles to enter gas phase at a given temp. a measure of “stickiness” of liquid particles to each other more “sticky” less likely to vaporize In general: LOW v.p. not very “sticky” more likely to vaporize In general: HIGH v.p. NOT all liquids have same vapor pressure at same temp.

Bell Ringer If the pressure inside a tire is 248 kPa, how many millilmeters of mercury is that? 1860

How Vapor Pressure is Measured Animation by Raymond Chang All rights reserved

Vapor Pressure manometer DEMOS Vapor Pressure manometer

Behavior of a liquid in a closed container

Table H

Boiling Point Explained 100 80 CHLOROFORM PRESSURE (kPa) 60 ETHANOL b.p. = 78oC 40 20 WATER b.p. = 100oC 20 40 60 80 100 TEMPERATURE (oC) Volatile substances evaporate easily (have high v.p.’s). BOILING  when vapor pressure = confining pressure (usually from atmosphere) atmospheric pressure is 101.3 kPa

Formation of a bubble is opposed by the pressure of the atmosphere

Boiling vs. Evaporation Boiling point: atmospheric pressure = vapor pressure AIR PRESSURE 15psi Revolutionary process - fast VAPOR PRESSURE 15 psi Lyophilization – freeze drying Evaporation: molecules go from liquid to gas phase gas Evolutionary process - slow liquid

measures atmospheric pressure Barometer Empty space (a vacuum) Hg Weight of the mercury in the column atmosphere (atmospheric pressure) measures atmospheric pressure

Barometers Mount Everest Sea level fraction of 1 atm average altitude (m) (ft) 1 1/2 5,486 18,000 1/3 8,376 27,480 1/10 16,132 52,926 1/100 30,901 101,381 1/1000 48,467 159,013 1/10000 69,464 227,899 1/100000 96,282 283,076 Barometers Mount Everest Every point on Earth’s surface experiences a net pressure called atmospheric pressure. • Pressure exerted by the atmosphere is considerable. • A 1.0-m2 column, measured from sea level to the top of the atmosphere, has a mass of about 10,000 kg, which gives a pressure of 100 kPa: pressure = (1.0 x 104kg) (9.807 m/s2) = 1.0 x105 Pa = 100 kPa 1.0 m2 • In English units, this is 15 lb/in2. Atmospheric pressure can be measured using a barometer, a closed, inverted tube filled with mercury. • The height of the mercury column is proportional to the atmospheric pressure, which is reported in units of millimeters of mercury (mmHg), also called torr. Standard atmospheric pressure is the atmospheric pressure required to support a column of mercury exactly 760 mm tall; this pressure is also referred to as 1 atmosphere (atm). • A pressure of 1 atm equals 760 mmHg exactly and is approximately equal to 100 kPa: 1 atm = 760 mmHg = 760 torr = 1.01325 x 105Pa = 101.325 kPa Pressure varies smoothly from the earth's surface to the top of the mesosphere. Although the pressure changes with the weather, NASA has averaged the conditions for all parts of the earth year-round. The following is a list of air pressures (as a fraction of one atmosphere) with the corresponding average altitudes. The table gives a rough idea of air pressure at various altitudes. Sea level Sea level On top of Mount Everest

Table H

Practice Vapor Pressure of 4 liquids wkst

Table H

Quiz 1.What is one way you can make a real gas act more ideal? 2. 92.1 kPa = _______ mmHg 3. If ethanol boils at 82°C, what is the atmospheric pressure? 4. In terms of pressure(s), when does a liquid boil? 5. Name of the two MOST ideal REAL gases?

Quiz 1. Spread out, high temp or low press 2. 691mmHg 3. 110 kPa 4. When vp = atm pressure 5. H or He

Bell Ringer According to Reference Table H, at what temperature will propanone boil if the atmospheric pressure is 70kPa?

Evaporation H2O(g) molecules (water vapor) H2O(l) molecules

DEMOS Boiling Water Boiling with dec. VP With Ice

Table H

Gas Laws

Show how pressure, volume, and temperature, are related to gases. Gas Laws Show how pressure, volume, and temperature, are related to gases. REMEMBER  P T V

The volume must increase! Gas Laws Hold whichever variable constant to adjust the other variable to see what would happen as a result of the desired change If the temperature remains constant and we lower the pressure, what must happen to the volume? P T V P T V The volume must increase!

The pressure must increase! Gas Laws If the temperature remains constant and we lower the volume, what must happen to the pressure? P T V P T V The pressure must increase!

Relationships between volume and pressure. Boyle's Law Relationships between volume and pressure.

DEMOS Vacuum Pump

Boyle’s Law: P and V as one increases, the other decreases inversely proportional pressure is caused by moving molecules hitting container walls If V is decreased and the # of molecules stays constant, there will be more molecules hitting the walls per unit of time

Boyle’s Law

Pressure vs. Volume for a Fixed Amount of Gas (Constant Temperature) Pressure Volume PV (Kpa) (mL) 100 500 50,000 150 333 49,950 200 250 50,000 250 200 50,000 300 166 49,800 350 143 50,500 400 125 50,000 450 110 49,500 600 500 400 Volume (mL) 300 The pressure for this data was NOT at 1 atm. Practice with this data: (where Pressure = 1 atmosphere) Volume Temp (oC) (K) V/T 63.4 L 500 773 0.0821 55.2 400 673 0.0821 47.0 300 573 0.0821 38.8 200 473 0.0821 As the pressure on a gas increases, the volume of the gas decreases because the gas particles are forced closer together. As the pressure on a gas decreases, the gas volume increases because the gas particles can now move farther apart. Boyle carried out some experiments that determined the quantitative relationship between the pressure and volume of a gas. Plots of Boyle’s data showed that a simple plot of V versus P is a hyperbola and reveals an inverse relationship between pressure and volume; as the pressure is doubled, the volume decreases by a factor of two. Relationship between the two quantities is described by the equation PV = constant. Dividing both sides by P gives an equation that illustrates the inverse relationship between P and V: V = constant = constant(1/P) or V  1/P P • A plot of V versus 1/P is a straight line whose slope is equal to the constant. • Numerical value of the constant depends on the amount of gas used in the experiment and on the temperature at which the experiments are carried out. • This relationship between pressure and volume is known as Boyle’s law which states that at constant temperature, the volume of a fixed amount of a gas is inversely proportional to its pressure. 200 100 0 100 200 300 400 500 Pressure (KPa)

Chucky’s Law (aka Charles Law) Relationship between volume and temperature

Charles’ Law: V and T if P is constant, gases expand when heated when T increases, gas molecules move faster and collide with the walls more often and with greater force to keep the P constant, the V must increase

Example: Boyle’s Law Consider a 1.53L sample of gaseous SO2 at a pressure of 5.6 x 103 Pa. If the pressure is changed to 1.5 x 104 Pa at constant temperature, what will be the new volume of the gas?

Practice 1. If the volume of a gas at 10.0oC is 100.0 ml, then what is the volume at -2.0oC? V1 =V2 T1 T2 T1 = 10oC 100.0 ml V2 = V1 = 100.0 mL 10.0oC -2.0oC T2 = -2.0oC 10.0 x V2 = -200 V2 = ? V2 = -20. ml We can’t have negative volumes, so we can’t use a temperature scale with negatives V1 =V2 T1 T2 With gas laws, ALWAYS USE KELVIN T1 = 10oC 283 K 100.0 ml V2 = V1 = 100.0 mL 283 K 271 K T2 = -2.0oC 271 K 283 x V2 = 27100 V2 = 95.7597 mL 96 mL V2 = ?

Gas Laws pkt Vapor Pressure wkst

Charles’ Law: V and T Animation Charles’ Law: the V of fixed mass of gas at constant P varies directly with temperature. What kind of graph is V vs. T? Animation

Son of Early of Cork, Ireland. Boyle's Law If n and T are constant, then PV = (nRT) = k This means, for example, that Pressure goes up as Volume goes down. A bicycle pump is a good example of Boyle's law. As the volume of the air trapped in the pump is reduced, its pressure goes up, and air is forced into the tire. Robert Boyle (1627 - 1691) Son of Early of Cork, Ireland.

Boyle’s Law As the pressure on a gas increases - the volume decreases 1 atm As the pressure on a gas increases - the volume decreases Pressure and volume are inversely related As the pressure on a gas increases 2 atm 4 Liters 2 Liters

Pressure-Volume Relationship 250 200 150 100 50 0.5 1.0 1.5 2.0 Volume (L) Pressure (kPa) (P3,V3) (P1,V1) (P2,V2) P1 = 100 kPa V1 = 1.0 L P2 = 50 kPa V2 = 2.0 L P3 = 200 kPa V3 = 0.5 L 2.5 P1 x V1 = P2 x V2 = P3 x V3 = 100 L x kPa

P vs. V (Boyle’s Data)

Charles’ Law discovered by French physicist, Jacques Charles in 1787 first person to fill balloon with hydrogen gas and make solo balloon flight

Example: Charles’ Law & Temp. A sample of gas at 15.0°C and 1.00 atm has a volume of 2.58 L. What volume will this gas occupy at 38.0°C and 1.00 atm? V1 =V2 T1 T2 P1 = 1.00 atm P2 = 1.00 atm T1 = 15.0oC = 288K T2 = 38.0oC = 311K V1 = 2.58 L V2 = ? 2.58 L V2 = 288K 311K V2 x 288K = 802L*K V2 = 2.79L

Bell Ringer If the pressure on a gas is decreased by ½, how much larger will the volume become? Which gases makes the most ideal gases real gases?

Cooling Curve Review

Gas Laws Lab

Bell Ringer Balloon #1 contains H2 gas Balloon #2 contains He gas Four identical balloons contain equal volumes of gas at STP. Balloon #1 contains H2 gas Balloon #2 contains He gas Balloon #3 contains O2 gas Balloon #4 contains N2 gas Which balloon would weigh the most? Explain According to the KMT, why would the balloons expand upon heating?

DEMOS Pressure Cooker

Bell Ringer If you have a basketball that has a volume of 2.2L at a pressure of 3.00atm. What would it’s volume be at Standard Pressure?

Let's Practice A. Increases As the temperature of a liquid increases, its vapor pressure A. Increases B. Decreases C. Remains the same According to Reference Table H, what is the vapor pressure of propanone at 45ºC? 70.0 kPa What is the name of the of the phase change that turns a solid directly into a gas? Sublimation Which liquid on Table H has the strongest intermolecular forces of attraction? Ethanoic Acid

Table H

1 x 1023 Avogadro's Hypothesis Amadeo Avogadro created two important ideas used in science 1. Hypothesis If we have two gases with the same temperature and pressure at the same volume, they will have the same number of molecules. Gases are made of mostly empty space, so the size of the individual molecules does not matter Example - A sample of H2(g) contains 1 x 1023 molecules at a particular volume at STP. How many molecules of CO2(g) takes up the same volume at STP? Same T, same P and same V = same # of molecules 1 x 1023

2. Molar volume of a gas In chemistry, we use very large numbers of atoms. So Avagadro created a large unit called - Mole = 602,000,000,000,000,000,000,000 objects Pair = 2 Dozen = 12 Mole = 6.02 x 1023 If we have one mole of ANY gas at standard temperature and pressure, it will take up 22.4 L of space Examples 1. How much room does 6.02 x 1023 molecules of N2(g) occupy at STP? One mole = 22.4 L 2. How much volume does 0.5 moles of CO2(g) occupy at STP? 11.2L

3. If we have 3.01 x 1023 molecules of CO2(g) at STP, what is the volume? 0.5 moles 11.2 L 4. How many molecules are in 44.8 L of H2S(g) at STP? 2 moles 2 x 6.02 x 1023 1.204 x 1024 5. If we have 9.03 x 1023 molecules of a gas at STP, what is the volume? 1.5 moles 33.6 L

Dalton’s Law of Partial Pressure

Dalton’s Law of Partial Pressure the total P of a mixture of gases is equal to the sum of partial P of component gases, no matter how many different gases PT = P1 + P2 + P3 + … Partial Pressure- P of each gas in mixture

Why? the particles of each gas in a mixture have an equal chance to hit the walls so each gas exerts P independent of that exerted by other gases total P is result of the total # of collisions per unit of wall area

Table H worksheet

Bell Ringer According to Reference Table H, which liquid will evaporate more rapidly? At what temperature does ethanol have the same vapor pressure as propanone at 68.5˚C?

Bell Ringer A gas sample has a volume of 25.0 ml at a pressure of 1.0 atm. If the new volume increases to 50.0 ml and the temperature remains constant, the new pressure will be?

Combined Gas Laws

Combined Gas Laws a gas often changes in T, P, and V all at once the other gas laws can be combined into one law Combined Gas Law- relationship between P, V, and T of a fixed amount of gas

Combined Gas Laws Example - A gas is collected at 273 K and 2.00 atm to a volume of 50.0 ml. What is the new pressure of a gas if the temperature drops to 200.0 K and the volume increases to 75.0 ml? P1 = 2.00 atm P2 = ?   V1 = 50 mL V2 = 75.0 ml T2 = 200.0 K T1 = 273 K 2.00 x 50 ml P2 x 75.0 ml = 273 K 200.0 K 20,475 x P2 = 20,000 0.977 atm P2 = 0.97680 atm

Combined Gas Laws A Helium-filled balloon has volume of 50.0 L at 25°C and 1.08 atm. What volume will it have at 0.855 atm and 10.°C? P1 = 1.08 atm P2 = 0.855 atm   V2 = ? V1 = 50.0 L T2 = 10.°C = 283 K T1 = 25°C = 298 K (1.08 atm)(50.0 L) (0.855 atm)(V2) = 298 K 283 K 254.79 x V2 = 15282 60. L V2 = 59.9788 L

Bell Ringer Which 5.0 ml sample of NH3 will take the shape of and completely fill a closed 100.0 ml container? A. NH3(s) C. NH3(g) B. NH3(l) D. NH3(aq)

Gas Laws and Boyles Problems Sub Gas Laws and Boyles Problems

Combined Gas Laws

Bell Ringer Which sample at STP has the same number of molecules as 5 liters of NO2(g) at STP? 5 grams of H2(g) 5 liters of CH4(g) 5 moles of O2(g) 5 x 1023 molecules of CO2(g)

Combined Gas Laws a gas often changes in T, P, and V all at once the other gas laws can be combined into one law Combined Gas Law- relationship between P, V, and T of a fixed amount of gas

Combined Gas Laws Example - A gas is collected at 273 K and 2.00 atm to a volume of 50.0 ml. What is the new pressure of a gas if the temperature drops to 200.0 K and the volume increases to 75.0 ml? P2 = ? P1 = 2.00 atm V2 = 75.0 ml V1 = 50 mL T2 = 200.0 K T1 = 273 K 2.00 x 50 ml P2 x 75.0 ml = 273 K 200.0 K 20,475 x P2 = 20,000 0.977 atm P2 = 0.97680 atm

Combined Gas Laws A Helium-filled balloon has volume of 50.0 L at 25°C and 1.08 atm. What volume will it have at 0.855 atm and 10.°C? P1 = 1.08 atm P2 = 0.855 atm V2 = ? V1 = 50.0 L T2 = 10.°C = 283 K T1 = 25°C = 298 K (1.08 atm)(50.0 L) (0.855 atm)(V2) = 298 K 283 K 254.79 x V2 = 15282 60. L V2 = 59.9788 L

Bell Ringer A 1.00-mole sample of a neon gas occupies a volume of 22.4 liters @ 298K and 101.3 kPa. Calculate the density of this sample. 0.827 g/L

Jeopardy

Exam

Bell Ringer Using Table H, how would you have to adjust your cooking time of pasta high in the mountains?

Water rapidly boiling on a stove

Water rapidly boiling on a stove

Pressure Cooker http://gotethnicfoods.com/pictures/Regular/AGLS020.jpg Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

120oC https://www.storesonlinepro.com/files/1730690/uploaded/Presto%2001755%20Pressure%20Cooker%20Canner.jpg

Pressure Cooker http://gotethnicfoods.com/pictures/Regular/AGLS020.jpg Copyright © 2006 Pearson Benjamin Cummings. All rights reserved.

120oC https://www.storesonlinepro.com/files/1730690/uploaded/Presto%2001755%20Pressure%20Cooker%20Canner.jpg

Bell Ringer A gas occupies a volume of 560.ml at a temperature of 100.°C. To what temperature must the gas be changed if it is to occupy 400.ml, with the pressure remaining unchanged?

Table H

Heating / Cooling Curve of Water 140 steam 120 water and steam 100 liquid water 80 Temperature (oC) 60 Heating Cooling 40 ice and water 20 ice -20 Heat added at a constant rate