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CHEMISTRY – DR. BEIN Amsterdam High School

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A DR. E. BEIN PRODUCTION © 2002 – 2007 Dr. Edward C. Bein 2

© Freeman Publishers

Miscellaneous links to copyrighted materials with available web access.

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Law of definite proportions

PURE SUBSTANCES

Law of Law of definite multiple Proportions 2 Proportions

• Elements and compounds are considered a pure substances because each has a uniform and definite composition as well as distinct properties. • The smallest unit of a pure substance that retains the properties of that substance is an atom or molecule.

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Heterogeneous Vs homogeneous

ORGANIZATION OF MATTER Matter

Pure substances

Mixtures Solutions

Compounds

Mixtures

Homogeneous

Heterogeneous 4

Elements

Colloids

Suspensions

TM Mixture/compound

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MIXTURES • When two or more substances combine yet retain their individual properties, the result is called a mixture. • Mixtures can be separated by physical means.

MIXTURES • A heterogeneous mixture is not the same, or uniform, throughout. • One type of heterogeneous mixture is called a suspension because the particles are large enough to settle out and can be separated by using a filter.

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COLLOIDS • Contain particles so small that they will not normally settle out. • If particles are tiny enough the effect of molecular collisions can be seen. • Tiny particles may be detected by shining a bright light, the Tindal effect.

HOMOGENEOUS SOLUTIONS • Homogeneous mixtures are uniform throughout. • All solutions are homogeneous mixtures.

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HOMOGENEOUS OR HOMOGENEOUS

Extensive & Intensive properties

PHYSICAL PROPERTIES

• Can be observed and measured without changing the chemical makeup of the substance. • Density – Which is a measure of the mass of a material in a given volume. – The density of water is one milliliter (mL) of water has a mass of 1.00 g, the density of water is 1.00 g/mL. – One milliliter of volume is exactly equal to one cubic centimeter (1 cm3),

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PHYSICAL PROPERTIES • Density of Water – Water has a density of 1g/cm3 @ 4C – Anything with a density less than water will float in water. – Anything with a density more than water will sink in water.

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DENSITY • Gas particles are small, so 1 mol. of any gas at standard conditions occupies 22.4L. • Particles in a liquid or solid are close enough to attract each other, so the volume occupied by 1 mol of any liquid or solid will vary.

DENSITY • What are the densities of the three substances shown? • O2 = 1.4 X 10-3 g/mL • Al = 2.7 g/mL • H20 = 1.0 g/mL

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STANDARD TEMPERATURE & PRESSURE • To make sure of identical conditions a standard condition has been set. • STP = Standard Temperature & Standard Pressure

PHYSICAL CHANGES • In a physical change, the identity of the substance remains the same. • Melting • Boiling • Bending

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CHEMICAL CHANGES

Physical vs chemical

• Transform into new substances. • A chemical change can often be detected by – The formation of a gas or solid – A color change – A change on the surface of a solid – A temperature change 17

Al + Br2

TM

Do handout worksheet for homework.

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LAW OF CONSERVATION OF MATTER • In a chemical reaction, matter is neither created nor destroyed. • Bonds can be broken, formed or rearranged. In chemical reactions we must balance all atoms.

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LAW OF CONSERVATION OF MATTER • In a chemical reaction, matter is neither created nor destroyed. • The original atoms remain, only their arrangements have been changed.

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LAW OF CONSERVATION OF MATTER

2Cu(s) + O2(g) 

2CuO(s)

• We use numbers in front of the material called coefficients.

– Coefficients indicate the relative number of units of each substance 21

CARBON CYCLE

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CARBON CYCLE • Burning coal: C(s) + O2(g) → CO2 (g) • Burning natural gas : CH4(g) + 2O2 (g) → CO2 (g) +2H2O(g) • Burning gasoline : 2C8H18(g) + 25O2(g) → 16CO2(g) + 18H2O(g) • Additionally, clearing forests reduces the conversion of CO2 23

FORMULA UNIT • Individual molecules are written as molecular formulas • Ionic compounds are crystals made of many ions. • Chemists use the term formula unit to denote the smallest number ratio of the compound.

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EMPIRICAL FORMULA • An empirical formula is the smallest number ratio in any compound. • For ionic compounds the formula unit and empirical formula are the same. • For molecules, empirical formulas show the ratio of all atoms. C6H12O6 CH2O

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WRITING CHEMICAL EQUATIONS

• Complete an atom inventory: • Change the coefficients, as necessary.

– You cannot change subscripts. – That would change the compound. 26

• You can “add” materials because most reactions occur where there are excesses.

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• Assign worksheet for homework. 27

WRITING CHEMICAL EQUATIONS • Chemical equations are very efficient methods of conveying a lot of information. 2 H2(g) + O2(g)  2 H2O(g)

Two molecules each Only one molecule 28

All are gases

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WRITING CHEMICAL EQUATIONS • Chemical equations are very efficient methods of conveying a lot of information. 2 H2(g) + O2(g) 2 H2O(g) • Read the equation.

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WRITING CHEMICAL EQUATIONS • Rules that may help you:

– If polyatomic ions, such as NO3– and CO32+ appear as both reactants and products, treat them as units. – If water is involved in the reaction, balance hydrogen and oxygen atoms last. – Re-count all atoms after you think an equation is balanced—just to be sure! 30

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SPECIFIC HEAT CAPACITY • The quantity of heat required to raise the temperature of 1 gram of a substance by one kelvin [J/(g•K)]. • Specific Heat Capacity is a unique physical property of different substances – Metals have low specific heat capacity – Non-metals have higher specific heat capacity – Water has an unusually large specific heat capacity 31

Q = mCT

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Specific Heat - Lab

THIS LAB WILL BE A VIRTUAL LAB.

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CALORIMETER

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• Specific heat capacity is the quantity of Thermal energy (heat) needed to raise the temperature of 1 g of a material By 1°C (same size units as Kelvins). • In effect, specific heat capacity is a measure of a material's "storage Capacity" for thermal energy.

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HOW DOES HEAT CHANGE TEMPERATURE? • The lower a material's specific heat capacity, the more its temperature increases when a certain quantity of energy is added. • The higher the specific heat capacity, the smaller the temperature increase will be for a given quantity of added energy.

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HOW DOES HEAT CHANGE TEMPERATURE? • Materials with higher specific heat capacities can store more thermal energy . • Water has a very high specific heat capacity. • What happens to the temperature of water as you add heat as compared to a metal?

• Thus, land near water has it’s temperature moderated by the heat sink properties of the water.

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WATER • The only ordinary liquid found naturally in our environment.

Hydrogen bonding 0:06

• Many substances dissolve readily in water • Water-based solutions are called aqueous solutions. • Even water that seems pure never is.

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PHASES OF WATER

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TM

PHASES OF WATER

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PHASES/STATES

Most important for this course

Phase

Definition

Solid

Fixed volume. Fixed shape. Molecules vibrate in fixed close positions.

Liquid

Fixed volume. Variable shape. Molecules free to move past each other in close positions.

Gas

Variable volume. Fits container. Molecules move freely & widely spaced.

Plasma

Most of matter in universe. Stars. Highly energetic. Electrons and positive ions moving freely & widely spaced.

Heat Applied

Sliding scale

Phases Movie

Volume change

CHANGE-OF-STATE MODELS FOR WATER

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MOLECULAR ARRANGEMENT • Which of the three states has the most ordered arrangement of atoms? – Solid

• Which of the three states has atoms with the greatest kinetic energy? – gas 43

ENTROPY • Entropy can simply be thought of as the amount of disorder in a system. • All kinds of energy spontaneously spread out from where they are concentrated to where they are more dispersed, if they're not hindered from doing that. • Things tend to a more disordered state.

Greater entropy 44

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ENTROPY • Systems in nature tend to undergo changes toward lower energy and higher entropy.

Entropy & ΔS changes

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MOLECULAR SPACING

Which phase has greater entropy?

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PHASE CHANGE LAB

PHASE CHANGES

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ENERGY FOR PHASE CHANGE • As the material changes from one phase to another, there is no change in temperature. – Potential energy changes but kinetic remains the same. • The amount of energy can be calculated

q = mHf For melting or freezing q = mHv For boiling or condensation

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PHASE CHANGES

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PHASE CHANGES • Is the change from a liquid to a solid endothermic or exothermic? • Exothermic • Think about what is happening to the heat of the molecules undergoing change.

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PRESSURE OF A GAS • When gas particles hit the walls of their container they cause pressure. • More particles hitting walls = higher pressure. • Heat up the gas, its particles move more quickly, stronger collisions = higher pressure.

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NORMAL BP & MP • Water boils when the pressure exerted by the molecules push back equally with the pressure of the atmosphere. • Since pressure can change, scientists have set standard conditions. • At 1 atm pressure (101.3 kpa) boiling point is called Normal B.P. 54

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NORMAL BP & MP • Water freezes when its’ molecules can go into their open crystal lattice structure. • Extra pressure can prevent the molecules from attaining this shape. • Since pressure can change, scientists have set standard conditions. • At 1 atm pressure (101.3 kpa) freezing point is called Normal F.P.

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VAPOR PRESSURE • As the temperature increases the speed and energy of the liquid molecules increases. • This increases the force the molecules can exert. • This force is called vapor pressure.

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VAPOR PRESSURE • At different temperatures the liquid exerts different amounts of pressure. • Recall that BP is the temperature at which the pressure of the liquid equals the pressure of the atmosphere.  as pressure changes BP changes

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BP & PRESSURE

• What happens to the boiling point of water as the pressure increases?

VAPOR PRESSURES • At what pressure does water boil at 25°C? • about 3 kPa

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VAPOR PRESSURES • At what pressure does ethanol boil at 25°C? • about 7 kPa

VAPOR PRESSURES

• At what pressure does propanone boil at 25°C? • About 31 kPa

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VAPOR PRESSURES

• How do the vapor pressures of the liquids compare?

DYNAMIC EQUILIBRIUM

PREVIOUS SLIDE

• A liquid-vapor equilibrium develops in a closed system. – At first there is only liquid present, but molecules are beginning to evaporate. – Evaporation continues at a constant rate. Some vapor molecules are beginning to condense to liquid. – Equilibrium has been reached between the rate of condensation and the rate of evaporation. Evaporation & vapor pressure 1:04 64

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DYNAMIC EQUILIBRIUM

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DYNAMIC EQUILIBRIUM • Humidity is due to evaporated water, or water vapor, in the air. How are the liquid molecules able to evaporate? • Some of the molecules have enough kinetic energy to overcome the attractive forces in the liquid.

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DYNAMIC EQUILIBRIUM • The system will always tend toward equilibrium, which is a saturated solution. • If you shift the system the rates of dissolution and precipitation will change, and a new equilibrium would be reached.

DISTILLATION WORKS • Because of the varying vapor pressures and therefore the varying boiling points, things can be separated by distillation.

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DISTILLATION

DISTILLATION

Cherry Coke

Sugar + flavoring

• Distillation of cherry coke separates which components?

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SEPARATION BY DISTILLATION LAB 2:27

CAUTION: Do not allow all of the liquid to boil from the flask.

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PETROLEUM REFINING P190 • Crude oil is a mixture of many compounds. • A process is known as fractional distillation separates compounds in each fraction have a particular range of boiling points. • Fractions with higher boiling points contain larger molecules.

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FRACTIONAL DISTILLATION How Oil Refining Works Related Articles

CHEMQUANDARY Imagine that you are given samples of three solids. You are told that each is a pure element. You examine the first sample. It is a black solid that feels soft and a bit “greasy” to the touch. It leaves black marks when rubbed on the table. It is a useful lubricant and a fairly good conductor of electricity. A gram of the material sells for less than a penny. You then inspect the second sample. It is a colorless, glasslike solid. It leaves deep scratch marks when rubbed on the table—in fact, it is among the hardest substances known. It is useful as an abrasive and as a coating for saw blades. It is a nonconductor of electricity. Depending on the quality of the solid piece, it can sell for $50 per gram or more than $20,000 per gram. 74

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CHEMQUANDARY Finally you look at the third sample. It is a fine, powdery solid made up of the roundest molecules found in nature. Although samples of the substance are present in prehistoric layers of Earth’s crust, it was only discovered in 1985. Although the price of this substance is dropping, in pure form—gram-forgram—it is currently more expensive than gold. These are, indeed, three distinctly different substances. Yet you are told that all three samples are exactly the same element. In other words, each is composed only of atoms of one particular element—no impurities, no mixtures, no compounds. How can atoms of one element make up such different materials? What additional information do you need to explain this? What element is being described? 75

ALLOTROPES

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ALLOTROPES • Allotropes are two or more forms of an element that have distinctly different physical or chemical properties. • Carbon – Graphite, diamond & fullerene – O2 & O3

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OTHER ALLOTROPES • Sulfur • Oxygen • Phosphorus • Do not confuse this with different states, that occur for most materials. 78

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Properties of Gas - Lab

P248

THIS LAB WILL BE DONE AS A DEMONSTRATION For report answer questions. Write about your observations. No additional discussion/conclusion necessary.

PRESSURE Pressure =

Force Area

Gas exerts pressure as the molecules bang against the walls of objects.

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PRESSURE UNITS Unit

Symbol

Definition/relationship

Pascal

Pa

Sl pressure unit In 1 Pa = 1N/m2

Millimeter of mercury

mm Hg

pressure that supports a 1 mm mercury column in a barometer

Atmosphere

atm

average atmospheric pressure at sea level and 0°C 1 atm = 760 mm Hg =1.013 x105 Pa =101.3 kPa

Torr

torr

1 torr =1 mm Hg

PRESSURE • If a scuba diver is exposed to a pressure of 3 atm, what is the equivalent pressure in kilopascals? 303.9 kPa

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PRESSURE • In this class we will use the Pascal as the unit of pressure. – The force of 1 Newton pushing down on 1m2 – 1 N is about the force exerted by a 100 g object. • Imagine 100 mL of H2O spread over 1m3

• Since Pa are so small we will commonly use kPa (kiloPascals) 83

APPLICATIONS OF PRESSURE – BUILDING SKILLS 2

Using what you have learned about pressure, answer these questions.

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ATMOSPHERIC PRESSURE • Why does the mercury rise in the barometer tube? • Air exerts pressure on the surface of the mercury in the dish and forces the mercury in the tube to a height equal to the atmospheric pressure Atmosphere TM

ATMOSPHERIC PRESSURE • How would atmospheric pressure change with an increase in elevation? • • It would decrease  Pressure & Elevation

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ATMOSPHERIC PRESSURE

• Normal atmospheric pressure is about 101 300 Pa. • SI 1 atm = 101.3 kPa

MOVEMENT OF ATOMS & MOLECULES • Recall that atoms & molecules are moving in solids, liquids & gases. – Solid – vibrating around fixed positions – Liquid – free to move, but still close – Gas – free to move & far apart

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What is a mole

AVOGADRO’S HYPOTHESIS

• Equal volumes of gases at the same temperature and pressure have equal numbers of particles. • Regardless of which gas they contain.

Mole

THE KINETIC MOLECULAR THEORY OF GASES states that for an ideal gas, all gas particles: • are in random, constant, straight-line motion. • are separated by great distances relative to their size; the volume of the gas particles is considered negligible. • have no attractive forces between them. • have collisions that may result in a transfer of energy between gas particles, but the total energy of the system remains constant. 90

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INFORMATIONAL SLIDE The translational motion of atoms and molecules gives gases their thermodynamic temperature, pressure, and the vast majority of their volume. Here, the size of helium atoms relative to their spacing is shown to scale under 136 atmospheres of pressure. These roomtemperature atoms have a certain, average speed (slowed down here two trillion–fold). Five atoms are colored red to facilitate following their motions.

RANDOM, CONSTANT, STRAIGHT-LINE MOTION • move in a straight line until they collide with another particle or the walls of the container.

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SEPARATED BY GREAT DISTANCES VOLUME OF THE GAS PARTICLES IS CONSIDERED NEGLIGIBLE

• Most of the volume of a gas is therefore empty space.

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NO ATTRACTIVE FORCES

• No attraction or repulsion between particles or walls of container.

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TOTAL ENERGY REMAINS CONSTANT • Collisions between gas particles with the walls of the container are perfectly elastic. – None of the energy of a gas particle is lost when it collides with another particle or with the walls of the container.

• The average kinetic energy of a collection of gas particles depends on the temperature of the gas and nothing else.

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THE KINETIC MOLECULAR THEORY OF GASES • How does the real world compare to ideal gas laws?

–Particles do have size –There are attractive & repulsive forces. • Phase changes can occur

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KINETIC MOLECULAR THEORY • Use kinetic molecular theory to explain how the vapor pressure of the ethanol rises with temperature. • More energy enters the ethanol system, causing more molecules to evaporate and the vapor pressure to increase.

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KINETIC MOLECULAR THEORY • How does vapor pressure depend on the liquid's molecular composition? • Molecular composition and shape determine the strength of molecular attraction. The stronger the attraction is, the lower the vapor pressure will be.

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BOYLE’S LAW – PV RELATIONSHIPS

P259

• As more pressure is applied to a gas the volume decreases. • KMT explains this.

–Large spaces between the molecules. –Pressure is caused by collisions of particles.

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PV RELATIONSHIPS • As pressure increases the volume decreases proportionally.

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PV RELATIONSHIPS • As the volume of a sample of gas is reduced, the number of molecular collisions with the container wall increase and thus the gas pressure-increases proportionally.

Pressure & Volume Pressure-Volume Data (Constant Temperature) Pressure (kPa)

Volume PV (L)

100

500

50 000

150

333.3

50 000

200

250

50 000

250

200

50 000

300

166.7

50 000

350

142.8

50 000

400

125

50 000

450

111

50 000

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PV Relationships • Boyle recognized this inverse relationship. • He developed the formula: PxV=k pressure x volume = constant Which can be rewritten

P1 V1 = P2 V2

BOYLE’S LAW • What volume corresponds to a pressure of 300 kPa? 150 kPa? • V = 167 L • V = 333 L • What type of relationship does this graph show? (an

inverse proportion)

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PV RELATIONSHIPS

BUILDING SKILL P262

• Do for HW

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BOYLE’S LAW – VIRTUAL LAB

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TV Relationships - Lab

P263

Be sure you indicate the top and bottom of the tube on your paper toweling. Otherwise you will not be able to get data. This will be a complete report

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TV Relationships

Building SkillsP266

• Charles recognized this direct relationship. • He developed the formula: V = k volume / temperature = constant T • Which can be rewritten • V1 V2 = • T1 T2 108

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CHARLES’S LAW Volum e (mL)

°C

K

V/T

1094

273

546

2.00

748

100

373

2.01

568

10

283

2.01

545

1

274

1.99

545

0

273

2.00

546

-1

272

2.01

403

-73

200

2.02

199

-173

100

1.99

100

-223

50

2.00

PRESSURE VS. TEMPERATURE FOR A GAS AT CONSTANT VOLUME

Kelvin Celsius

• When working with gases, temperature must be measured in Kelvins. • Why does increasing the temperature increase the pressure in a fixed volume? • KMT – more energetic collisions.

conversions

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CHARLES’ LAW – VIRTUAL LAB

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COMBINED GAS LAWS • We can combine Boyle’s & Charles’ Laws to a useful formula: P1V1 T1

=

P 2V 2 T2

• This allows us to calculate real life situations. • We can restore STP parameters. 112

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PROPERTIES OF GASES

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STEAM CLEANING • The interior of a tank car was washed out & cleaned with steam. Then all the outlet valves were shut and the tank car was sealed. All the workers went home for the evening and when they returned, this is what they found.

•Apparently as the tank car cooled, it collapsed. The shell on these tank cars is 7/16th's thick steel. 114

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REAL VS IDEAL GAS • When does a gas behave most like an ideal gas? • When the space between is largest. – Low pressure

• When the attraction is least. – High temperature

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REAL VS IDEAL

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DALTON’S LAW OF PARTIAL PRESSURE • a mixture of gases in a container, the total pressure is equal to the sum of the pressures of each gas. Where P1 is the partial pressure of gas 1, P2 is the partial pressure of gas 2, and so on...

Dalton’s law animation 117

DALTON’S LAW OF PARTIAL PRESSURE

How many molecules of H2

What will total pressure be? How many Moles Total?

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GAS COLLECTED OVER WATER

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GAS COLLECTED OVER WATER • Write the balanced chemical equation for hydrogen production in the process shown. Zn(s) + H2SO4(aq) →ZnSO4(aq) + H2(g)

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GAS COLLECTED OVER WATER • If Ptotal is 101.3 kPa, what is the pressure of the dry hydrogen gas that is collected?

The total pressure is a combination of water vapor and the gas collected.

GAS COLLECTED OVER WATER • If Ptotal is 101.3 kPa, what is the pressure of the dry hydrogen gas that is collected? • Data chart @ 20°C • 101.3 - 2.34 = 98.96 kPa

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VAPOR PRESSURE OF WATER AT VARIOUS TEMPERATURES Temperature (°C)

Pressure H2O (kPa)

Temperature (°C)

Pressure H2O (kPa)

0

0.61

55

15.75

5

0.87

60

19.93

10

1.23

65

25.02

15

1.71

70

31.18

20

2.34

75

38.56

25

3.17

80

47.37

30

4.25

85

57.82

35

5.63

90

70.12

40

7.38

95

84.53

45

9.59

100

101.32

50

12.34

105

120.79

WHAT IS THE PRESSURE OF A DRY GAS COLLECTED 108.41 kPa AT 45°C AND 118.00 KPA? Temperature (°C)

Pressure H2O (kPa)

Temperature (°C)

Pressure H2O (kPa)

0

0.61

55

15.75

5

0.87

60

19.93

10

1.23

65

25.02

15

1.71

70

31.18

20

2.34

75

38.56

25

3.17

80

47.37

30

4.25

85

57.82

35

5.63

90

70.12

40

7.38

95

84.53

45

9.59

100

101.32

50

12.34

105

120.79

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WHAT IS THE PRESSURE OF A DRY GAS COLLECTED AT 80°C AND 130.00 KPA? 82.63 kPa Temperature (°C)

Pressure H2O (kPa)

Temperature (°C)

Pressure H2O (kPa)

0

0.61

55

15.75

5

0.87

60

19.93

10

1.23

65

25.02

15

1.71

70

31.18

20

2.34

75

38.56

25

3.17

80

47.37

30

4.25

85

57.82

35

5.63

90

70.12

40

7.38

95

84.53

45

9.59

100

101.32

50

12.34

105

120.79

GRAHAM'S LAW • Law of diffusion – Lighter particles diffuse faster than heavier ones.

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GRAHAM'S LAW DEMO

• Cotton plugs moistened with ammonia and hydrogen chloride were placed at opposite ends of the glass tube several minutes before this photograph was taken. Why does the white ring of ammonium chloride form closer to the right end than the left end?

GRAHAM'S LAW 17 What are GFMs

36.5

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GRAHAM'S LAW • What is the balanced equation for the chemical reaction? HCl(g) + NH3(g) → NH4CI(s)

Kinetic Molecular Theory

Modeling Matter P269

• My favorite analogy is kindergarteners in the gym – Kids banging into walls = pressure • Increase → more or faster kids

– Kids take up more space = volume • Increase → bigger room, more spread out kids

– Kids moving faster = hotter • Increase → give them pixie stix

– Less space, increase speed 130

or put more kids in = more collisions.

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Avogadro’s number

AVOGADRO'S LAW • Equal volumes of gases at the same temperature and pressure contain the same number of “molecules”. (particles)

• All gases have the same molar volume if they are at the same temperature and pressure. • At conditions of 0°C and 1 atmosphere (STP), the molar volume of any gas is 22.4 L. 131

Worksheets

Mole diagram Allow many conversions Stoichiometry – the math of chemistry Conversions 132

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Molar Conversions

Molar Mass GFM

LITERS OF GAS AT STP Molar Volume (22.4 L/mol)

MASS Molar Mass IN (g/mol) GRAMS

MOLES

Molarity (mol/L)

LITERS OF SOLUTION

6.02  1023

particles/mol

NUMBER OF PARTICLES

Mass

133

Moles

The first thing you need to find! The first thing you need to find! The first thing you need to The first thing you need tofind! find!

The first thing you need to find! MOLES

The first thing you need to find! The Thefirst firstthing thingyou youneed needto tofind! find! 134

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Mass 

Molarity

Use the formula on table T

MOLES

Molarity

(mol/L)

LITERS OF SOLUTION

135

Mass

Moles

Mass to moles

Moles to mass

X MASS Molar Mass GFM IN (g/mol) GRAMS

MOLES

÷ GFM

Mole mass 136

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Volume

Moles

LITERS OF GAS AT STP Molar Volume X (22.4 L/mol)

÷ MOLES

Molar volume

137

# of particles

Moles

Moles To Atoms

Moles To Molecules

MOLES

÷ Avoga dro

X

NUMBER OF PARTICLES

6.02  1023

particles/mol

138

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X away

X

÷ toward

÷

X MOLES

÷

X

÷

139

Molar Conversions, made easy LITERS OF GAS AT STP

MASS IN GRAMS

X

To Particles

Molar Volume X (22.4 L/mol)

÷

GFM

Counting atoms from mass

Counting

MOLES

(g/mol)

÷

Grams

molecules from mass

÷

X

NUMBER OF PARTICLES

6.02  1023

particles/mol

140

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Review  The

gram formula mass of C7H16  The gram formula mass of CaCO3  The gram molecular mass of oxygen gas  How many grams are in 0.900 mol Pd? 141

Review  How

many liters of gas are in 2.5 mol. of Oxygen?  How many liters of gas are in 2.5 mol. of Nitrogen?  How many liters of gas are in .25 mol. of Oxygen?

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Review  What

is the mass in grams of 5.90 mol octane, C8H18?  What is the number of moles in 432 grams of barium nitrate, Ba(NO3)2?  What is the number of moles in 15.0 grams of AsH3?  How many moles in 0.25 grams of (NH4)2Cr2O7?

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Review  How

many particles (atoms) are in 1.5 mol. of W?  How many particles (atoms) are in 1.5 mol. of Au?  How many particles (molecules) are in 1.5 mol. of C6H12O6?  How many particles (empirical formulas) are in 1.5 mol. of Na2CO3?

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Expanded Mole Diagram

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Expanded Mole Diagram LITERS OF GAS AT STP

MASS IN GRAMS

LITERS OF GAS AT STP

MOLES

MOLES

NUMBER OF PARTICLES

NUMBER OF PARTICLES

MASS IN GRAMS

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Expanded Mole Diagram How many moles of this substance

Mole Ratios

Produce or need how many moles of this substance

To cross the tracks you use the mole ratio derived from the balanced equation.

Mole Ratio

Problems

Mole Ratios

Mole Molecules Mass

147

Fill in everything that you know.

Mass Relationships

EASY Put in the conversions.

Find the number of moles. Then find whatever you need.

You can travel from any box to any adjacent box. 148

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Molar Ratios

 

Mole mass calculations Illustration of moles reacting

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Molar Ratios

• Mole mass calculations • Illustration of moles reacting

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Molar Volume & Reactions of Gases

Conservation Rules

Conservation of mass

Building Skills P270

Law of Conservation of mass

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HABER PROCESS • How many grams of ammonia will you be able to make if you start with 200 liters of hydrogen gas @ STP? • How much nitrogen do you need to complete this reaction>

– Moles? – Grams? – Liters @ STP?

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• Dalton’s Law – Animation – Calculation

• Density and ideal gas • Diffusion in water & air • Gas & Molecular motion • gas particles colliding • gas V & P • Narrated gas laws 153

• ideal gas law – Calculations – How to increase volume of a balloon

• KMT • Osmotic pressure • Temp and KE – movie

• Vapor Pressure & BP Movie with graphs – Narrated description – Water & sugar solution – Curves – & Dynamic Equilibrium – Vapor Pressure vs. Temperature

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• Diffusion of H2 • Diffusion NH3 & HCl • Gay Lussac law • Charles law demo with flasks – Charles law virtual lab w graph

• Inverted flask w water & screen

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• Balloon & liquid N2 movie w Charle’s law • Boyle's law movie – Boyle's law virtual lab w graph – Boyle's law movie – Demonstrations

• • • • •

CO2 pressure in carbonated beverage Diffusion illustration Effect of pressure on the solubility of a gas Effect of temperature on the vapor pressure Effusion & diffusion

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A DR. E. BEIN PRODUCTION © 2002 – 2015 Dr. Edward C. Bein

© Freeman Publishers

Miscellaneous links to copyrighted materials with available web access. 157

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