In Figure 12.31, what happens to the density of gas

Calculate the ratio of effusion rates for nitrogen ( N 2) and neon (Ne)

Calculate the ratio of diffusion rates for carbon monoxide and carbon dioxide.

Challenge What is the rate of effusion for a gas that has a molar mass twice that of a gas that effuses at a rate of 3.6 mol/min?

What is the partial pressure of hydrogen gas in a mixture of hydrogen and helium if the total pressure is 600 mm Hg and the partial pressure of helium is 439 mm Hg?

Find the total pressure for a mixture that contains four gases with partial pressures of 5.00 kPa, 4.56 kPa, 3.02 kPa, and 1.20 kPa.

Find the partial pressure of carbon dioxide in a gas mixture with a total pressure of 30.4 kPa if the partial pressures of the other two gases in the mixture are 16.5 kPa and 3.7 kPa.

Challenge Air is a mixture of gases. By percentage, it is roughly 78 percent nitrogen, 21 percent oxygen, and 1 percent argon. (There are trace amounts of many other gases in air.) If the atmospheric pressure is 760 mm Hg, what are the partial pressures of nitrogen, oxygen, and argon in the atmosphere?

Explain Use the kinetic theory to explain the behavior of gases.

Describe how the mass of a gas particle affects its rate of effusion and diffusion.

Explain how gas pressure is measured.

Explain why the container of water must be inverted when a gas is collected by displacement of water.

Calculate Suppose two gases in a container have a total pressure of 1.20 atm. What is the pressure of Gas B if the partial pressure of Gas A is 0.75 atm?

Infer whether or not temperature has any effect on the diffusion rate of a gas. Explain your answer.

Explain what determines a substances state at a given temperature.

Compare and contrast intermolecular forces and describe intramolecular forces.

Evaluate Which of the molecules listed below can form hydrogen bonds? For which of the molecules would dispersion forces be the only intermolecular force? Give reasons for your answers. a. H 2 b. H 2 S c. HCl d. HF

Intepret Data In a methane molecule (C H 4 ), there are four single covalent bonds. In an octane molecule ( C 8 H 18 ), there are 25 single covalent bonds. How does the number of bonds affect the dispersion forces in samples of methane and octane? Which compound is a gas at room temperature? Which is a liquid?

Contrast the arrangement of particles in solids and liquids.

Describe the factors that affect viscosity.

Explain why soap and water are used to clean clothing instead of water alone.

Compare a unit cell and a crystal lattice

Describe the difference between a molecular solid and a covalent network solid.

Explain why water forms a meniscus when it is in a graduated cylinder.

Infer why the surface of mercury in a thermometer is convex; that is, the surface is higher at the center.

Predict which solid is more likely to be amorphousone formed by allowing a molten material to cool slowly to room temperature or one formed by quickly cooling the same material in an ice bath.

Design an experiment to compare the relative abilities of water and isopropyl alcohol to support skipping stones. Include a prediction about which liquid will be better, along with a brief explanation of your prediction.

Explain how the addition or removal of energy can cause a phase change.

Explain the difference between the processes of melting and freezing.

Compare deposition and sublimation.

Compare and contrast sublimation and evaporation.

Describe the information that a phase diagram supplies

Explain what the triple point and the critical point on a phase diagram represent.

Determine the phase of water at 75.00C and 3.00 atm using Figure 12.29.

What is an elastic collision?

How does the kinetic energy of particles vary as a function of temperature?

Use the kinetic-molecular theory to explain the compression and expansion of gases.

List the three basic assumptions of the kinetic-molecular theory.

Describe the common properties of gases.

Compare diffusion and effusion. Explain the relationship between the rates of these processes and the molar mass of a gas.

In Figure 12.31, what happens to the density of gas particles in the cylinder as the piston moves from Position A to Position B?

Baking Explain why the baking instructions on a box of cake mix are different for high and low elevations. Would you expect to have a longer or a shorter cooking time at a high elevation?

What is the molar mass of a gas that takes three times longer to effuse than helium?

What is the ratio of effusion rates of krypton and neon at the same temperature and pressure?

Calculate the molar mass of a gas that diffuses three times faster than oxygen under similar conditions.

What is the partial pressure of water vapor in an air sample when the total pressure is 1.00 atm, the partial pressure of nitrogen is 0.79 atm, the partial pressure of oxygen is 0.20 atm, and the partial pressure of all other gases in air is 0.0044 atm?

What is the total gas pressure in a sealed flask that contains oxygen at a partial pressure of 0.41 atm and water vapor at a partial pressure of 0.58 atm?

Mountain Climbing The pressure atop the worlds highest mountain, Mount Everest, is usually about 33.6 kPa. Convert the pressure to atmospheres. How does the pressure compare with the pressure at sea level?

High Altitude The atmospheric pressure in Denver, Colorado, is usually about 84.0 kPa. What is this pressure in atm and torr units?

At an ocean depth of 76.2 m, the pressure is about 8.4 atm. Convert the pressure to mm Hg and kPa units.

Figure 12.32 represents an experimental set-up in which the left bulb is filled with chlorine gas and the right bulb is filled with nitrogen gas. Describe what happens when the stopcock is opened. Assume that the temperature of the system is held constant during the experiment.

Explain the difference between a temporary dipole and a permanent dipole.

Why are dispersion forces weaker than dipole-dipole forces?

Explain why hydrogen bonds are stronger than most dipole-dipole forces.

Compare intramolecular and intermolecular forces.

Hypothesize why long, nonpolar molecules would interact more strongly with one another than spherical nonpolar molecules of similar composition.

Polar Molecules Use relative differences in electronegativity to label the ends of the polar molecules listed as partially positive or partially negative. a. HF b. HBr c. NO d. CO

Draw the structure of the dipole-dipole interaction between two molecules of carbon monoxide.

Decide which of the substances listed can form hydrogen bonds. a. H 2 O b. H 2 O 2 c. HF d. N H

Decide which one of the molecules listed below can form intermolecular hydrogen bonds, and then draw it, showing several molecules attached together by hydrogen bonds. a. NaCl b. MgC l 2 c. H 2 O 2 d. C O

What is surface tension, and what conditions must exist for it to occur?

Explain why the surface of water in a graduated cylinder is curved.

Which liquid is more viscous at room temperature, water or molasses? Explain

Explain how two different forces play a role in capillary action.

Use the drawings in Figure 12.33 to compare the cubic, monoclinic, and hexagonal crystal systems.

What is the difference between a network solid and an ionic solid?

Explain why most metals bend when struck but most ionic solids shatter.

List the types of crystalline solids that are usually good conductors of heat and electricity

How does the strength of a liquids intermolecular forces affect its viscosity?

Explain why water has a higher surface tension than benzene, whose molecules are nonpolar.

Compare the number of particles in one unit cell for each of the following types of unit cells. a. simple cubic b. body-centered cubic

Predict which solid is more likely to be amorphous one formed by cooling a molten material over 4 h at room temperature or one formed by cooling a molten material quickly in an ice bath.

Conductivity Predict which solid will conduct electricity bettersugar or salt.

Explain why ice floats in water but solid benzene sinks in liquid benzene. Which behavior is more normal?

Given edge lengths and face angles, predict the shape of each of the following crystals. a. a = 3 nm, b = 3 nm, c = 3 nm; = 90, = 90, = 90 b. a = 4 nm, b = 3 nm, c = 5 nm; = 90, = 100, = 90 c. a = 3 nm, b = 3 nm, c =5nm; = 90, = 90 , = 90 d. a = 3 nm, b = 3 nm, c = 5 nm; = 90, = 90, = 120

How does sublimation differ from deposition?

Compare boiling and evaporation.

Define the term melting point.

Explain the relationships among vapor pressure, atmospheric pressure, and boiling point

Explain why dew forms on cool mornings

Snow Why does a pile of snow slowly shrink even on days when the temperature never rises above the freezing point of water?

Copy and label the solid, liquid, and gas phases, triple point, and critical point on Figure 12.34.

Why does it take more energy to boil 10 g of liquid water than to melt an equivalent mass of ice?

Use the kinetic-molecular theory to explain why both gases and liquids are fluids.

Use intermolecular forces to explain why oxygen is a gas at room temperature and water is a liquid.

Use the kinetic-molecular theory to explain why gases are easier to compress than liquids or solids.

At 25C and a pressure of 760 mm Hg, the density of mercury is 13.5 g/mL; water at the same temperature and pressure has a density of 1.00 g/mL. Explain this difference in terms of intermolecular forces and the kinetic-molecular theory

If two identical containers each hold the same gas at the same temperature but the pressure inside one container is exactly twice that of the other container, what must be true about the amount of gas inside each container?

List three types of intermolecular forces.

When solid sugar crystals are dissolved in a glass of water, they form a clear homogeneous solution in which the crystals are not visible. If the beaker is left out at room temperature for a few days, the crystals reappear in the bottom and on the sides of the glass. Is this an example of freezing?

Interpret Graphs Examine Figure 12.35, which plots vapor pressure versus temperature for water and ethyl alcohol. a. What is the boiling point of water at 1 atm? b. What is the boiling point of ethyl alcohol at 1 atm? c. Estimate the temperature at which water will boil when the atmospheric pressure is 0.80 atm

Hypothesize What type of crystalline solid do you predict would best suit the following needs? a. a material that can be melted and reformed at a low temperature b. a material that can be drawn into long, thin wires c. a material that conducts electricity when molten d. an extremely hard material that is nonconductive

Compare and Contrast An air compressor uses energy to squeeze air particles together. When the air is released, it expands, allowing the energy to be used for purposes such as gently cleaning surfaces without using a more abrasive liquid or solid. Hydraulic systems essentially work the same way, but involve compression of liquid water rather than air. What do you think are some advantages and disadvantages of these two types of technology?

Graph Use Table 12.6 to construct a phase diagram for ammonia. Table 12.6 Phase Diagram for Ammonia Selected Points Pressure (atm) Temperature (C) Triple point 0.060 -77.7 Critical point 112 132.2 Normal boiling point 1.0 -33.5 Normal freezing point 1.0 -77.7

Apply A solid being heated stays at a constant temperature until it is completely melted. What happens to the heat energy put into the system during that time?

Communicate Which processeffusion or diffusion is responsible for your being able to smell perfume from an open bottle that is located across the room from you? Explain.

Infer A laboratory demonstration involves pouring bromine vapors, which are a deep red color, into a flask of air and then tightly sealing the top of the flask. The bromine is observed to first sink to the bottom of the beaker. After several hours have passed, the red color is distributed equally throughout the flask. a. Is bromine gas more or less dense than air? b. Would liquid bromine diffuse more or less quickly than gaseous bromine after you pour it into another liquid?

Analyze Use your knowledge of intermolecular forces to predict whether ammonia (N H 3 ) or methane (C H 4 ) will be more soluble in water.

Evaluate List three changes that require energy and three that release energy

Evaluate Supercritical carbon dioxide is a liquid form of C O 2 used in the food industry to decaffeinate tea, coffee, and colas, as well as in the pharmaceutical industry to form polymer microparticles used in drug delivery systems. Use Figure 12.36 to determine what conditions must be used to form supercritical carbon dioxide. -56.6 31.1 Pressure (bar) 73 5 Temperature (C) Phase Diagram for CO2 Supercritical fluid Figure 12.36

You have a solution containing 135.2 g of dissolved KBr in 2.3 L of water. What volume of this solution, in mL, would you use to make 1.5 L of a 0.1 mol/L KBr solution? What is the boiling point of this new solution?

Identify each of the following as an element, a compound, a homogeneous mixture, or a heterogeneous mixture. (Chapter 3) a. air d. ammonia b. blood e. mustard c. antimony f. water

You are given two clear, colorless aqueous solutions. You are told that one solution contains an ionic compound, and one contains a covalent compound. How could you determine which is an ionic solution and which is a covalent solution? (Chapter 8)

Which branch of chemistry would most likely study matter and phase changes? (Chapter 1) a. biochemistry c. physical chemistry b. organic chemistry d. polymer chemistry

What type of reaction is the following? (Chapter 9) K 2 C O 3 (aq) + BaC l 2 (aq) 2KCl(aq) + BaC O 3 (s) a. combustion c. single-replacement b. double-replacement d. synthesis

Which chemist produced the first widely used and accepted periodic table? (Chapter 6) a. Dmitri Mendeleev c. John Newlands b. Henry Moseley d. Lothar Meyer

Musk is the basic ingredient of many perfumes, soaps, shampoos, and even foods such as chocolates, licorice, and hard candies. Both synthetic and natural musk molecules have high molecular weights compared to other perfume ingredients, and as a result, have a slower rate of diffusion, assuring a slow, sustained release of fragrance. Write a report on the chemistry of perfume ingredients, emphasizing the importance of diffusion rate as a property of perfume

Birthstones Find out what your birthstone is and write a brief report about the chemistry of that gem. Find out its chemical composition, which category its unit cell is in, how hard and durable it is, and what its approximate cost is at present

Propane gas is a commonly used heating fuel for gas grills and homes. However, it is not packaged as a gas. It is liquefied and referred to as liquid propane or LP gas. Make a poster explaining the advantages and disadvantages of storing and transporting propane as a liquid rather than a gas.

Other States of Matter Research and prepare an oral report about one of the following topics: plasma, superfluids, fermionic condensate, or Bose-Einstein condensate. Share your report with your classmates and prepare a visual aid that can be used to explain your topic

Why does solid iodine sublime readily? Use your knowledge of intermolecular forces to explain.

Why is liquid iodine not usually visible if crystals are heated in the open air?

Why is it necessary to use a sealed ampoule in this investigation?

Infer why the iodine solidifies when the tube is tilted.