Chapter 11 Mastering Chemistry

On a phase diagram, the vaporization curve is between

a liquid and a gas.

On a phase diagram, the sublimation curve is between

a solid and a gas.

On a phase diagram, the fusion curve is between

a solid and a liquid.

Capillary action occurs because...

adhesive forces are greater than cohesive forces.

Which halogen has the highest boiling point? Cl2 Br2 I2

I2

Identify the compound that does NOT have hydrogen bonding. H2O (CH3)2N(CH2)3CH3 CH3(CH2)2NH2 HF CH3(CH2)5NH2

(CH3)2N(CH2)3CH3

Open the phase diagram for CO2 given in the introduction again. Use the phase diagram for CO2 in the interactive activity and determine which of the following statements are correct. Check all that apply.

*When the pressure is 1 atm, there is no temperature at which the liquid phase of CO2 exists. *All three phases of CO2 exist simultaneously at the triple point. *Movement across boundary line BO corresponds to a phase change. *CO2 is a gas under normal conditions of temperature and pressure. When the pressure is 4 atm and the temperature is more than −56.7∘C, CO2 exists as a solid. CO2 forms a supercritical fluid at temperatures less than 31∘C.

Polonium

1 atom/unitcell

The normal boiling point of water is ________ at sea level.

100 Celsius

Give the coordination number for a body-centered cubic cell.

12 10 6 0 *8

In DNA, adenine and thymine have ________ hydrogen bonds between them.

2

Tungsten

2 atom/unitcell

How many compounds, of the ones listed below, have hydrogen bonding? CH3(CH2)2NH2 CH3(CH2)2NH(CH2)4CH3 (CH3CH2)2N(CH2)4CH3

2. CH3(CH2)2NH2 CH3(CH2)2NH(CH2)4CH3

Methylamine has a vapor pressure of 344 torr at -25∘C and a boiling point of -6.4∘C . Find ΔHvap for methylamine.

23 kJ/mol Use Calusius-Clapeyron Equation

Carbon disulfide has a vapor pressure of 363 torr at 25∘C and a normal boiling point of 46.3∘C. Find ΔHvap for carbon disulfide.

27 kJ/mol Use Clausius-Clapeyron Equation

How much energy is required to heat 87.1 g acetone (molar mass=58.08 g/mol) from a solid at -154.0°C to a liquid at -42.0°C? The following physical data may be useful. ΔHfus = 7.27 kJ/mol Cliq = 2.16 J/g°C Cgas = 1.29 J/g°C Csol = 1.65 J/g°C Tmelting = -95.0°C

29.4 kJ

In DNA, cytosine and guanine hydrogen bond to each other with ________ hydrogen bonds.

3

How many hydrogen bonds does Thymine and Adenine have? Cytosine and Guanine? (DNA)

3 2

A mixture containing 21.4 g of ice (at exactly 0.00 ∘C) and 75.3 g of water (at 70.0 ∘C) is placed in an insulated container. Assuming no loss of heat to the surroundings, what is the final temperature of the mixture?

41.9 ∘C 32.6 ∘C 38.2 ∘C *36.8 ∘C

How much energy is required to vaporize 135 g of butane at its boiling point? The heat of vaporization for butane is 23.1 kJ/mol.

53.7 kJ (Molar mass and multiply)

How long would it take for 1.50 mol of water at 100.0 ∘C to be converted completely into steam if heat were added at a constant rate of 18.0 J/s ?

56.3 min (Convert mol to g, multiply by deltaHvap, multiply by 18 J/s)

Calculate the amount of heat (in kJ) required to vaporize 2.51 kg of water at its boiling point. ( ΔHvap=40.7 kJ/mol at 100 ∘C)

5670 kJ

How much energy must be removed from a 125 g sample of benzene (molar mass= 78.11 g/mol) at 425.0 K to liquify the sample and lower the temperature to 335.0 K? The following physical data may be useful. ΔHvap = 33.9 kJ/mol ΔHfus = 9.8 kJ/mol Cliq = 1.73 J/g°C Cgas = 1.06 J/g°C Csol = 1.51 J/g°C Tmelting = 279.0 K Tboiling = 353.0 K

67.7 kJ

Tungsten has a body-centered cubic unit cell. How many atoms of W are present in each unit cell? Express your answer as an integer.

8/8+1= 2

Nickel has a face-centered cubic unit cell. How many atoms of Ni are present in each unit cell? Express your answer as an integer.

8/8+6/2= 4

Mercury is a poisonous metal that is used in thermometers. When mercury is at temperatures below its freezing point it has a simple cubic unit cell. How many atoms of Hg are present in each unit cell? Express your answer as an integer.

8/8= 1

6. How much energy is required to vaporize 98.6 g of ethanol (C2H5OH) at its boiling point, if its ΔHvap is 40.5 kJ/mol? A. 11.5 kJ B. 39.9 kJ C. 52.8 kJ D. 18.9 kJ E. 86.7 kJ

86.7 kJ

8. How much energy is required to heat 36.0 g H2O from a liquid at 65°C to a gas at 115°C? The following physical data may be useful. ΔHvap = 40.7 kJ/mol Cliq = 4.18 J/g°/sup>C Cgas = 2.01 J/g°/sup>C Csol = 2.09 J/g°/sup>C Tmelting = 0°/sup>C Tboiling = 100°/sup>C A. 10.9 kJ B. 91.7 kJ C. 63.5 kJ D. 87.7 kJ E. 52.7 kJ

87.7 kJ

How much energy is required to heat 36.0 g H2O from a liquid at 65°C to a gas at 115°C? The following physical data may be useful. ΔHvap = 40.7 kJ/mol Cliq = 4.18 J/g°/sup>C Cgas = 2.01 J/g°/sup>C Csol = 2.09 J/g°/sup>C Tmelting = 0°/sup>C Tboiling = 100°/sup>C

87.7 kJ

13. How much ice (in grams) would have to melt to lower the temperature of 355 mL of water from 26 ∘C to 5 ∘C? (You must consider the enthalpy in cooling the water, as well as the enthalpy in melting the ice and the enthalpy to heat the melted ice from 0∘C up to the system's final temperature of 5 ∘C. Also assume that the density of water is 1.0 g/mL.) Express your answer using two significant figures.

88 g

What factors cause changes between the liquid and gas state? A gas can be converted into a liquid by heating. A gas can be converted into a liquid by cooling. A liquid can be converted to a gas by heating. A gas can be converted into a liquid by increasing the pressure of a gas sample. A gas can be converted into a liquid by decreasing the pressure of a gas sample. A liquid can be converted to a gas by cooling.

A gas can be converted into a liquid by cooling. A liquid can be converted to a gas by heating. A gas can be converted into a liquid by increasing the pressure of a gas sample.

What SAE oil would a car need for the summer?

A high SAE number oil.

What are the correct conditions for forming a hydrogen bond?

A hydrogen atom acquires a partial positive charge when it is covalently bonded to an F atom. Hydrogen bonding occurs when a hydrogen atom is covalently bonded to an N, O, or F atom. A hydrogen bond is possible with only certain hydrogen-containing compounds.

Phase Diagram

A map of the state(phase) of a substance as a function of pressure (y) and temperature (x).

Polar Molecules

A partial negative charge and a complementary positive charge. Asymmetric.

What is a phase diagram?

A phase diagram is simply a map of the phase of a substance as a function of pressure (on the y-axis) and temperature (on the x-axis)

What kind of molecule is miscible with water?

A polar molecule.

What factors cause changes between the solid and liquid state? A solid can be converted to a liquid by heating. A liquid can be converted to a solid by cooling. A liquid can be converted to a solid by heating. A solid can be converted to a liquid by cooling.

A solid can be converted to a liquid by heating. A liquid can be converted to a solid by cooling.

Choose the molecule or compound that exhibits dipole-dipole forces as its strongest intermolecular force. BCl3 H2 CBr4 SO2 N2

SO2

What two forces result in capillary action?

Adhesive forces and cohesive forces.

Supercritical Fluid

Any substance beyond its critical point.

Crystalline Solids

Atoms and molecules are composed in 3D. (Ordered Structure)

Amorphous Solids

Atoms and molecules have no long-range order.

5. Choose the substance with the highest vapor pressure at a given temperature. A. CH3SCH3 B. RbCl C. SiS2 D. SbH3 E. BF3

BF3

Choose the substance with the highest vapor pressure at a given temperature. SiS2 BH3 SbH3 RbBr CH3OCH2CH3

BH3

Choose the substance with the lowest viscosity. SbBr3 AsBr5 SBr2 BeBr2 OBr2

BeBr2

Identify the compound that does not have dipole-dipole forces as its strongest force. CH3 I HCBr3 CO2 CH2 Cl2 CH3OCH3

CO2

3. Which is expected to have the largest dispersion forces? A. BeCl2 B. C12H26 C. F2 D. C3H8

C12H26

Which is expected to have the largest dispersion forces? F2 C9H20 SiH4 CH4

C9H20

Which molecules have dipole forces? CO2 CH2Cl2 CH4

CH2Cl2

Choose the substance with the lowest surface tension. C6H6 CH3SeCH2CH3 (CH3)2SO H2Se CH3CH2CH2CH3

CH3CH2CH2CH3

Identify the compound with the lowest boiling point. (CH3)2O CH3CH2CH3 CH3CN CH3OCH3 CH3CHO

CH3CH2CH3

Identify the compound with the highest dipole moment. CH3CHO CH3CH2CH3 CH3OCH3 (CH3)2O CH3CN

CH3CN

Which molecules have dipole-dipole forces? Cl4 CH3Cl HCl

CH3Cl HCl

4. Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force. A. C2H6 B. CH3OH C. CH2Br2 D. SBr2 E. None of the above compounds exhibit hydrogen bonding.

CH3OH

Choose the compound that exhibits hydrogen bonding as its strongest intermolecular force. CH2Cl2 C2H6 CI4 CH3OH None of the above compounds exhibit hydrogen bonding.

CH3OH

Which of the following compounds exhibits hydrogen bonding? HCl CH3OH CH3Br CH3SCH3

CH3OH

Which substance has the highest boiling point? CH3OH CO N2

CH3OH

Which substance has the highest boiling point? CH3OH CO N2

CH3OH

Volatile Chemicals

Chemicals that evaporate easily.

10. Classify each solid as a covalent, ionic, metallic, or molecular solid. Drag the appropriate items to their respective bins.

Covalent: diamond Metallic: pure sodium Ionic: sodium sulfide Molecular: frozen carbon dioxide

As IM forces decrease, surface tension..... decreases increases stays the same

Decreases

Which intermolecular force correlates with dipole moment?

Dipole-Dipole Forces

1. Part A: What is the predominant intermolecular force in the liquid state of each of these compounds: hydrogen fluoride (HF), carbon tetrachloride (CCl4), and dichloromethane (CH2Cl2)? Drag the appropriate items to their respective bins. Part B Rank the following compounds in order of decreasing boiling point: sodium bromide (NaBr), methane (CH4), and chloroform (CHCl3) Rank from highest to lowest boiling point. To rank items as equivalent, overlap them.

Dipole-dipole forces: CH2Cl2 Hydrogen bonding: HF Dispersion forces: CCl4 Highest Boiling Point : NaBr Next Highest: CHCl3 Lowest Boiling Point: CH4

Which intermolecular force correlates with polarizability?

Dispersion Forces

In liquid methanol, CH3OH which intermolecular forces are present?

Dispersion, dipole-dipole and hydrogen bonding.

Nonvolatile Chemicals

Do not evaporate easily.

What is an example of sublimation?

Dry Ice

Is fusion endothermic or exothermic?

Endothermic

Is vaporization endothermic or exothermic?

Endothermic

Is condensation endothermic or exothermic?

Exothermic

Is freezing endothermic or exothermic?

Exothermic

Classify the following phase changes as exothermic processes or endothermic processes.

Exothermic Process: freezing, condensing, deposition Endothermic Process: melting, subliming, vaporizing

A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to

F, O, and N.

Which of the following has the smallest dipole-dipole forces? CO F2 CH3CH2Cl HI

F2

In the video, you can see that as heat is applied to a solid, it is converted into the liquid phase and then into the gas phase. This process can be studied by plotting the graph of temperature versus the time during which heat is applied to the system. Identify the states of matter and the processes that occur at each of the positions on the graph.

From lowest point on the graph to highest: Solid, Melting of a solid, Liquid, Boiling of the liquid, gas

A substance with no fixed volume or shape.

Gas

Identify the state of matter that is the most compressible.

Gas

Which one of the following has a low density? Liquid Solid Gas

Gas

Deposition

Gas to a solid

Which of the following compounds has the highest boiling point? H2S H2Se AsH3 H2O

H2O

Which of the following compounds exhibits dipole-dipole forces as its strongest attraction between molecules? HBr CO2 Kr H2 CH3NH2

HBr

Which molecules have dipole-dipole forces? HF CH3Cl SiH4

HF and CH3Cl

Choose the substance with the highest viscosity. C2H4Br2 (CH3CH2)2CO HOCH2CH2CH2CH2OH C8H18 CI4

HOCH2CH2CH2CH2OH

Choose the substance with the highest surface tension. CH3CH2CH2OH CH3CH2CH2OH CH3CH2I CH2F2 HOCH2CH2OH

HOCH2CH2OH

Which of the following substances would you predict to have the highest ΔHvap? CH3Cl HOCH2CH2OH CH3CH2OH CH3CH2CH2CH3 HF

HOCH2CH2OH

If hexane (C6H14), octane (C8H18), and octanol (C8H17OH) are heated evenly at different altitudes, rank them according to the order in which you would expect them to begin boiling. Hexane at high altitude Octane at sea level Octanol at sea level Octane at high altitude

Hexane at high altitude Octane at high altitude Octane at sea level Octanol at sea level

______________ temperatures cause higher evaporation rates. High Low

High

Substances have greater viscosity when they have ________ IM forces. Higher Lower

Higher

In the video, you can see that when heat is applied to a solid it is converted into the liquid phase and then into the gas phase. This process can be studied by plotting the graph of temperature versus the time during which heat is applied to the system. Using this information, arrange the average kinetic energy of the molecules for the following options in decreasing order. Rank from highest to lowest. To rank items as equivalent, overlap them.

Highest to lowest: The average kinetic energy of the molecules after point d, The average kinetic energy of the molecules from point b to point c, the average kinetic energy of the molecules before point a

Rank from highest IM force to lowest. Dipole-Dipole Dispersion Hydrogen Bonding

Hydrogen Bonding -> Dipole-Dipole -> Dispersion

Explain why ice floats in water.

Ice is less dense than water.

Give the change in condition to go from a liquid to a gas.

Increase heat or reduce pressure.

Viscosity increases as molecule size _________________. Increases Decreases

Increases

What is the significance of crossing a line in a phase diagram?

It means that a phase transition has occurred.

________________ surface areas cause higher evaporation rates. Large Small

Large.

A substance with a fixed volume but no fixed shape.

Liquid

What properties do supercritical fluids hold?

Liquid and Gas

Freezing

Liquid to a solid

What are the main properties of liquids (in contrast to gases and solids)? Liquids have a definite volume. Liquids have much higher densities in comparison to gases. Liquids have an indefinite shape and do not assume the shape of their container. Liquids are easily compressed. Liquids have an indefinite shape and assume the shape of their container. Liquids are not easily compressed. Liquids do not have a definite volume. Liquids have lower densities in comparison to gases.

Liquids have a definite volume. Liquids have much higher densities in comparison to gases. Liquids have indefinite shape and assume the shape of their container. Liquids are not easily compressed.

For automobile engines, identify the best choice of motor oil.

Low SAE for Maine in the winter and high SAE for Florida in the summer.

You are a researcher for a golf club manufacturer. You are given two identical looking cubes of a metal alloy. You are informed that they are made of the exact same material, but one is crystalline, whereas the other is amorphous. It is your job to determine which one is amorphous because this one is more stress-resistant and is useful in reinforcing golf clubs. Which of the following is the best way to determine which is which?

Melt both cubes and look for a broader range of melting temperatures. The one that melts over a broader range of temperatures is the amorphous solid. Melt both cubes and measure the range of melting temperatures. The one that melts over a narrower range of temperatures is the amorphous solid. *Determine the density of each cube. The less dense cube is the amorphous solid. Determine the density of each cube. The more dense one is the amorphous solid.

Fusion

Melting; Solid to a liquid

11. Which of the following substances should have the highest melting point? A. F2 B. CO2 C. SrS D. MgO E. Kr

MgO

14. Identify each of the following solids as molecular, ionic, or atomic. Drag the appropriate items to their respective bins.

Molecular: Br2 (s) and CS2 (s) Ionic: BaS (s) Atomic: Na (s)

Rank the crystal lattice structures in order of decreasing efficiency of space in the structure. Rank from most to least efficient use of space. To rank items as equivalent, overlap them.

Most effective to least: Hexagonal close packing = face-centered cubic, body-centered cubic, simple cubic

The general form of a phase diagram is given below. Observe that this phase diagram is divided into three regions by the blue boundary lines similar to the way the interactive phase diagram for CO2 was divided. Compare this general form of this phase diagram with the interactive phase diagram for CO2 and classify points a through g on the phase diagram according to the number of phases present at each point.

One phase: a, b, c Two phases: e, d, f Three phases: g

15. Part A Classify each property as associated with a liquid that has strong or weak intermolecular forces. Drag the appropriate items to their respective bins. Part B Arrange the liquids pentane (CH3CH2CH2CH2CH3), pentanol (CH3CH2CH2CH2CH2OH), and pentanal (CH3CH2CH2CH2CHO) in order of decreasing viscosity, surface tension, and boiling point. Rank from highest to lowest viscosity, surface tension, and boiling point. To rank items as equivalent, overlap them.

Part A: Strong intermolecular forces: high viscosity, high boiling point, high surface tension, low vapor pressure Weak intermolecular forces: low viscosity, low boiling point, low surface tension, high vapor pressure Part B: Highest viscosity, surface tension, and boiling point: pentanol The next highest: pentanal Lowest viscosity, surface tension, and boiling point: pentane

An oxide of rhenium crystallizes with the unit cell depicted here (where rhenium = gray and oxygen = red)(Figure 1) . What is the formula of the oxide? Express your answer as a chemical formula.

ReO3

Critical Point

Represents the temp and pressure above which the supercritical point exists. Where a liquid and gas can no longer be distinguished.

The hydrides of group 5A are NH3, PH3, AsH3, and SbH3. Arrange them from highest to lowest boiling point.

SbH3, NH3, AsH3, SbH3.

What is the strongest type of intermolecular force present in CHCl3?

dipole-dipole

A substance with a fixed volume and fixed shape.

Solid

Sublimation

Solid to a gas

You are given six samples of carbon dioxide (CO2) that are stored at different temperatures and at different pressures. Using the interactive activity showing the phase diagram of CO2, determine the phases of each of the samples and classify them according to which phase they are in. Keep in mind that the temperature and pressure are not to scale. Drag the appropriate items to their respective bins.

Solid: -90degC and 72.9atm, -78.5degC and 5.1atm Liquid: 0degC and 72.9atm, 20degC and 60atm Gas: 20degC and 2atm, 31degC and 1atm

Consider the following two substances and their vapor pressures at 298 K. Substance Vapor pressure (mmHg) A 275 B 459 Based on this information, compare the characteristics of the two substances. Drag each item to the appropriate bin.

Substance A: Has a higher boiling point Has a higher heat of vaporization Substance B: Has weaker intermolecular forces Is a gas at 300 mmHg

A paper clip floating on the top of water is an example of

Surface Tension

Suppose that 0.48 g of water at 25∘C condenses on the surface of a 55-g block of aluminum that is initially at 25∘C. If the heat released during condensation goes only toward heating the metal, what is the final temperature (in degrees Celsius) of the metal block? (The specific heat capacity of aluminum, Cs,Al, is 0.903 J/(g⋅∘C).)

Tf = 49 ∘C

The forces between polar molecules are known as

dipole-dipole forces

Capillary Action

The ability of a liquid to flow against gravity up a narrow tube.

Miscibility

The ability to mix without separating into two states.

Sometimes when we heat food in the microwave, the lid of the container pops off. Why does this occur?

The air and water vapor inside the container are expanding.

Heat of Fusion

The amount of heat required to melt 1 mol of a solid.

Enthalpy of Sublimation

The amount of heat required to sublime 1 mol of a solid to a gas.

Enthalpy of Vaporization

The amount of heat required to vaporize 1 mole of liquid to a gas.

Adhesive Forces

The attraction between molecules and the surface of a tube.

Cohesive Forces

The attractions between the molecules themselves.

Intermolecular Forces

The attractive forces that exist among the particles that compose matter.

When a solid is placed in a container and heat is applied, a phase change occurs. Watch the video and identify which of the following statements are correct.

The average kinetic energy of the system changes while all of a solid is converted to a liquid. *When a solid is converted to a liquid, heat is absorbed. The temperature increases while all of a liquid is converted to a gas. When heat is applied to a solid, the molecular motion decreases as the temperature increases. *Temperature remains constant while all of a solid is converted to a liquid.

An oxide of titanium crystallizes with the following unit cell (titanium = gray; oxygen = red)(Figure 1) . What is the formula of the oxide? Express your answer as a chemical formula.

TiO2

Thermal Energy

The energy associated with the movement of molecules and atoms.

Surface Tension

The energy required to increase the surface area by a unit amount.

When a small ice cube at -10∘C is put into a cup of water at room temperature, which of the following plays a greater role in cooling the liquid water: the warming of the ice from -10∘C to 0∘C , or the melting of the ice?

The melting of ice.

Vapor Pressure

The pressure of a gas in dynamic equilibrium with it's liquid.

Critical Pressure (Pc)

The pressure required to bring about a transition to a liquid at Tc.

Viscosity

The resistance of a liquid to flow.

Critical Temperature (Tc)

The temp above which a liquid cannot exist regardless of pressure.

Define critical point.

The temperature and pressure above which a supercritical fluid exists.

Boiling Point

The temperature at which the liquid's vapor pressure equals the external pressure.

Normal Boiling Pt.

The temperature of a liquid where its vapor pressure equals 1 atm.

Condensation

The transition of a gas to a liquid.

What happens to the vapor pressure of a substance when its surface area is increased at constant temperature?

The vapor pressure remains the same.

Fresh vegetables with high water content do not freeze well. Explain.

Water expands when it freezes and damages the cell wall.

______________ IM forces cause a higher evaporation rate. Stronger Weaker

Weaker

Dispersion Force

Weakest Force: Exhibited in all molecules and atoms. Result of fluctuations in electron distribution.

Hydrogen Bonding

When H is bonded with N, O or F.

Which of the following statements are correct? When a solid is converted to a liquid, heat is absorbed. The average kinetic energy of the system changes while all of a solid is converted to a liquid. When heat is applied to a solid, the molecular motion decreases as the temperature increases. Temperature remains constant while all of a solid is converted to a liquid. The temperature increases while all of a liquid is converted to a gas.

When a solid is converted to a liquid, heat is absorbed. Temperature remains constant while all of a solid is converted to a liquid.

Ion-Dipole Force

When an ionic compound is mixed with a polar compound. (Aqueous solutions).

Dynamic Equilibrium

When the rate of a reverse process equals that of the forward process. ex- when condensation = evaporization

Permanent Dipole

When two atoms in a molecule have substantially different electronegativities.

Triple Point

Where all three states exist in equilibrium.

X-rays with a wavelength of 1.64 Å scatter at an angle of 31.5 ∘ from a crystal. If n=1, what is the distance between planes of atoms in the crystal that give rise to this scattering? Express your answer with the appropriate units.

d = 1.57 Å

2. What is the strongest type of intermolecular force present in NH2CH3? A. dispersion B. dipole-dipole C. hydrogen bonding D. ion-dipole E. none of the above

hydrogen bonding

Calculate the amount of heat (in kilojoules) required to vaporize 2.58 kg of water at its boiling point.

q = 5830 kJ

What phase transition occurs when the pressure is decreased to 760 mmHg at constant temperature?

solid to liquid *liquid to gas liquid to solid solid to gas

The line connecting the triple point and the critical point on a phase diagram represents _____. the temperature and pressure combinations above which only a supercritical fluid can exist the temperature and pressure combinations at which the liquid and solid states are equally stable and at equilibrium the temperature and pressure combinations at which the liquid and gas states are equally stable and at equilibrium the temperature and pressure combinations at which the solid and gas states are equally stable and at equilibrium

the temperature and pressure combinations at which the liquid and gas states are equally stable and at equilibrium

How much heat is evolved in converting 1.00 mol of steam at 130.0 ∘C to ice at -50.0 ∘C? The heat capacity of steam is 2.01 J/(g⋅∘C) and of ice is 2.09 J/(g⋅∘C).

|Q| = 57.2 kJ

The vapor pressure of dichloromethane, CH2Cl2, at 0 ∘C is 134 mmHg. The normal boiling point of dichloromethane is 40. ∘C. Calculate its molar heat of vaporization. Express your answer to three significant figures and include the appropriate units.

ΔHvap = 30.9 kJ/mol

What is the Enthalpy of Vaporization for water?

ΔHvap = 40.7 kJ/mol

12. Which of the following is considered a nonbonding atomic solid? A. Ca B. Ne C. K D. Cu E. I2

Ne

Nickel

4 atom/unitcell

Calculate the amount of heat required to completely sublime 67.0 g of solid dry ice (CO2) at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 kJ/mol.

49.2 kJ

What volume will 135 g of butane occupy at 745 torr and 35 ∘C?

59.9 L (PV=nRT)

How much heat energy, in kilojoules, is required to convert 52.0 g of ice at −18.0 ∘C to water at 25.0 ∘C ?

24.8 kJ Go through phase changes. Solid -> liquid calculations

Dipole-Dipole Forces

Exists between all molecules that are polar.

Which halogen has the highest boiling point? Br2 I2 Cl2

I2

16. Part A Consider the following two substances and their vapor pressures at 298 K. Substance Vapor pressure (mmHg) A. 275 B. 459 Based on this information, compare the characteristics of the two substances. Drag each item to the appropriate bin. Part B The vapor pressure of dichloromethane, CH2Cl2, at 0 ∘C is 134 mmHg. The normal boiling point of dichloromethane is 40. ∘C. Calculate its molar heat of vaporization. Express your answer to three significant figures and include the appropriate units.

Part A: Substance A: higher boiling point and has a higher heat of vaporization Substance B: Has weaker intermolecular forces and is a gas at 300 mmHg Part B: ΔHvap = 30.9 kJ/mol

9. Part A: At 100 ∘C and 1 atm, water is in which phase? A. solid B. liquid C. gas D. supercritical fluid E. solid-liquid equilibrium F. liquid-gas equilibrium G. solid-gas equilibrium Part B Enter the critical temperature of water. Express your answer with the appropriate units. https://drive.google.com/file/d/0B4_51_spvHBTYy1IZjE3TXZrUHc/view?usp=sharing Part C At -57 ∘C and 2 atm, carbon dioxide is in which phase? Hints A. gas B. liquid C. solid D. supercritical fluid E. solid-liquid equilibrium F. liquid-gas equilibrium G. solid-gas equilibrium H. solid-liquid-gas equilibrium Part D At -30 ∘C and 1 atm carbon dioxide is in the gas phase. From these conditions, how could the gaseous CO2 be converted into liquid CO2? A. Increase the temperature. B. Decrease the temperature. C. Increase the pressure. D. Decrease the pressure. https://drive.google.com/file/d/0B4_51_spvHBTbEFIQ2JodXB6TVU/view?usp=sharing

Part A: liquid-gas equilibrium Part B: 374 degrees C Part C: gas Part D: increase pressure (use links for answer)

7. What happens to the temperature of a mixture of ice and liquid water as heat is applied at a constant rate? A. It is impossible to predict how the temperature will change unless you know the amount of ice and water that is present before the heating begins. B. The temperature of the mixture does not change at all until all the ice has melted, at which point it increases at a constant rate. C. The temperature of the mixture slowly increases as the ice melts. Once all the ice has melted, the temperature of the liquid water continues to rise, but at a faster rate. D. The temperature of the mixture increases as the ice melts, and then continues to increase at the same rate once all the ice is melted.

The temperature of the mixture does not change at all until all the ice has melted, at which point it increases at a constant rate.

Vaporization

The transition of a liquid to a gas.