Chapter 12

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

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 liquid’s 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.

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. $$ \begin{aligned} \text { a. } a &=3 \mathrm{nm}, b=3 \mathrm{nm}, c=3 \mathrm{nm} ; \alpha=90^{\circ}, \beta^{\circ}=90 \\ \gamma &=90^{\circ} \\\ \text { b. } a &=4 \mathrm{nm}, b=3 \mathrm{nm}, c=5 \mathrm{nm} ; \alpha=90^{\circ}, \beta^{\circ}=100 \\ \gamma &=90^{\circ} \\ \text { c. } a &=3 \mathrm{nm}, b=3 \mathrm{nm}, c=5 \mathrm{nm} ; \alpha=90^{\circ}, \beta^{\circ}=90 \\ \gamma &=90^{\circ} \\ \mathrm{d} &=3 \mathrm{nm}, b=3 \mathrm{nm}, c=5 \mathrm{nm} ; \alpha=90^{\circ}, \beta^{\circ}=90 \\ \gamma &=120^{\circ} \end{aligned} $$

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?

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 25°C 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.

List three types of intermolecular forces

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?

Communicate Which process—effusion 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.

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) . $$ \begin{array}{ll}{\text { a. air }} & {\text { d. ammonia }} \\ {\text { b. blood }} & {\text { e. mustard }} \\ {\text { c. antimony }} & {\text { f. water }}\end{array} $$

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) \(\begin{array}{ll}{\text { a. biochemistry }} & {\text { c. physical chemistry }} \\ {\text { b. organic chemistry }} & {\text { d. polymer chemistry }}\end{array}\)

What type of reaction is the following? (Chapter 9\()\) \(\mathrm{K}_{2} \mathrm{CO}_{3}(\mathrm{aq})+\mathrm{BaCl}_{2}(\mathrm{aq}) \rightarrow 2 \mathrm{KCl}(\mathrm{aq})+\mathrm{BaCO}_{3}(\mathrm{s})$$ \begin{array}{l}{\text { a. combustion } \quad \text { c. single-replacement }} \\ {\text { b. double-replacement } \text { d. synthesis }}\end{array}\)

Which chemist produced the first widely used and accepted periodic table? (Chapter 6\()\) \(\begin{array}{ll}{\text { a. Dmitri Mendeleev }} & {\text { c. John Newlands }} \\ {\text { b. Henry Moseley }} & {\text { d. Lothar Meyer }}\end{array}\)

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?