Chapter 12 Tro

Which noble gas has the highest boiling point?

Xe

Which state of matter has a high density and a definite volume?

both solids and liquids

If we supply additional heat to a solid in equilibrium with its liquid at the melting point, the thermal energy added is used to:

change solid to liquid.

Silicon is which type of solid

covalent atomic solid

Gaseous water vapor can frost the windows of a car on a cold morning. This process of a gas changing directly into a solid is known as:

deposition.

Which intermolecular force found in CCl2H2 is the strongest?

dipole-dipole forces

What types of forces exist between I2 molecules?

dispersion forces

Which intermolecular force increases with increasing molar mass?

dispersion forces

Which intermolecular force is due to the formation of an instantaneous dipole?

dispersion forces

Which intermolecular force is present in all molecules and atoms?

dispersion forces

Which intermolecular forces are found in CCl4 ?

dispersion forces

Which intermolecular forces are found in CO2?

dispersion forces

A situation where two opposite processes are occurring at equal rates, and no net change is taking place, is called:

dynamic equilibrium.

Which state of matter has a low density and an indefinite volume?

gases

Which state of matter has a low density and is easily compressed?

gases

The amount of heat required to melt one mole of a solid is called the:

heat of fusion.

You can increase the vapor pressure of a liquid by:

increasing temperature.

What are the principal forces holding ice together?

intermolecular forces

The ability of sodium chloride to mix with water is most likely due to:

ion-dipole force

Which intermolecular force is the strongest?

ion-dipole force

NaCl is which type of solid?

ionic solid

When you make ice cubes:

it is an exothermic process.

Which state of matter has a high density and an indefinite shape?

liquids

Copper is which type of solid?

metallic atomic solid

Dry ice (solid C ) is which type of solid?

molecular solid

Substance A is a molecular compound that dissolves in gasoline but not in water. The molecules of A are very likely:

nonpolar.

Paradichlorobenzene, a material used in "moth balls," is known to go directly from a solid form to a gaseous form. This process is known as:

sublimation

The tendency of a liquid to minimize its surface area is called:

surface tension

The reason for many of the unique properties of water is:

the ability to form hydrogen bonds.

The change of a substance from a liquid to a gaseous form is called:

vaporization

The measure of the resistance to the flow of a liquid is called:

viscosity.

Liquids that have high vapor pressure and low boiling points are called:

volatile liquids.

A 250 gram sample of water at the boiling point had 45.0 kJ of heat added.The heat of vaporization for water at the boiling point is 40.6 kJ/mol

20.0

How many grams of C4H10O can be melted by 2.00 x 10^3 J? Given "triangle"Hfus= .27 kJ/mol

20.4

How much energy does it take to melt a 16.87 g ice cube? "triangle"Hfus=6.02 kJ/mol

5.64 kJ

How many kJ of heat are needed to completely melt 17.3 g of O, given that the water is at its melting point? The heat of fusion for water is 6.02 kJ/mole

5.79

How many kJ of heat are needed to completely vaporize 23.4 g of O? The heat of vaporization for water at the boiling point is 40.6 kJ/mol

52.8

Which compound in liquid form will have the highest vapor pressure? A) CH4 B) CH3CH3 C) CH3C(O)CH3 D) CH3CH2OH E) not enough information

A) CH4

Assuming that the molecules carbon monoxide (CO) and nitrogen (N2) have similar electron clouds, which statement below is TRUE? A) CO has the higher boiling point because it experiences dipole-dipole forces. B) N2 has the higher boiling point because it experiences dipole-dipole forces. C) The N2 has the higher boiling point because it has greater dispersion forces. D) Both CO and N2 must have the same boiling point. E) none of the above

A) CO has the higher boiling point because it experiences dipole-dipole forces.

Which statement is TRUE in describing what occurs when a solid melts to a liquid? A) The process is endothermic and the heat of fusion is positive. B) The process is endothermic and the heat of fusion is negative. C) The process is exothermic and the heat of fusion is positive. D) The process is exothermic and the heat of fusion is negative. E) not enough information

A) The process is endothermic and the heat of fusion is positive.

Compare a small pot of water that is boiling vigorously to a large pot of water that is boiling gently. Which statement is TRUE? A) The small pot is boiling at higher temperature than the large pot. B) The large pot is boiling at a higher temperature than the small pot. C) Both pots are boiling at the same temperature. D) The vapor pressure of the liquid is greater than the pressure above the pot in each case. E) none of the above

C) Both pots are boiling at the same temperature.

Which substance below is an ionic solid? A) Cu (s) B) H2O (s) C) MgO (s) D) C6H12O6 (s) E) none of the above

C) MgO (s)

Which statement about boiling point is FALSE? A) The boiling point is higher for compounds with strong intermolecular forces. B) The boiling point is higher for compounds with a high viscosity. C) The boiling point of a compound is an absolute constant. D) The boiling point of a compound is higher for nonvolatile compounds. E) All of the above statements are true.

C) The boiling point of a compound is an absolute constant.

Which sequence correctly shows the increasing density of the three phases of water? A) solid < liquid < gas B) gas < liquid < solid C) gas < solid < liquid D) liquid < gas < solid E) none of the above

C) gas < solid < liquid

Evaporation is: A) increased by increasing temperature. B) an endothermic process. C) the opposite process to condensation. D) a cooling process for humans when they sweat. E) all of the above

E) all of the above

Increasing the intermolecular forces of a liquid will do which of the following? A) increase the viscosity B) decrease the evaporation rate C) increase the surface tension D) decrease the vapor pressure E) all of the above

E) all of the above

Intermolecular forces are responsible for: A) the taste sensations. B) the shape of protein molecules. C) the function of DNA. D) the existence of liquids and solids. E) all of the above

E) all of the above

What happens as you start to add heat to a solid substance? A) Thermal energy causes the components of the solid to vibrate faster. B) When the melting point is reached, the thermal energy is sufficient to overcome intermolecular forces holding the components at their stationary points. C) Increasing the rate of heating of a substance at its melting point only causes more rapid melting. D) If a liquid forms, continued heating results in increasing the liquid temperature. E) all of the above

E) all of the above

Which molecule below has hydrogen bonding? A) NH3 B) CH3OH C) H2O D) HF E) all of the above

E) all of the above

Why is water considered an unusual molecule? A) No molecule of similar size is a liquid at room temperature. B) No molecule of similar size has as high a boiling point. C) Water can dissolve many polar and ionic compounds. D) Water expands upon freezing. E) all of the above

E) all of the above

The opposite process of freezing is: A) evaporation. B) sublimation. C) boiling. D) condensation. E) none of the above

E) none of the above

Which statement below is FALSE? A) A hydrogen bond is the strongest of the intermolecular forces. B) A hydrogen atom must be bonded directly to fluorine, oxygen, or nitrogen to exhibit hydrogen bonding. C) The large electronegativity difference between hydrogen and an F, O, or N atom is essential for the formation of a hydrogen bond. D) A hydrogen bond is only 2-5% the strength of a typical covalent bond. E) none of the above

E) none of the above

Consider the three compounds below, then choose the compound(s) that have hydrogen bonding. 1) H2 2) CH4 3) HF

Only compound 3 has hydrogen bonding.

In northern climates, it is common to have a layer of frost form on cars that have been out overnight in the winter. During the day the frost layer disappears despite the temperature of the ice remaining below freezing. How?

The frost sublimes directly from solid ice to water vapor.

The rate of vaporization of a liquid can be increased by: 1. increasing the surface area 2. increasing the temperature 3. increasing the strength of the intermolecular forces

1 and 2 only

What is the heat of vaporization(kJ/mol) if it takes 3,457 J of heat to completely vaporize 2.68 moles of the liquid at its boiling point?

1.29

How many kJ of heat are needed to completely melt 1.70 moles of O, given that the water is at its melting point? The heat of fusion for water is 6.02 kJ/mole

10.2

How many kJ of heat are needed to completely vaporize 3.30 moles of H2O? The heat of vaporization for water at the boiling point is 40.6 kJ/mol

134

How many kilojoules of heat are needed to completely vaporize 42.8 grams of C4H10O at its boiling point? Given "triangle"Hvap = 26.5kJ/mol

15.3

How many kJ of heat are needed to completely melt 95.3 g of copper metal, given that the metal is at its melting point? The heat of fusion for this metal is 13.113.1 kJ/mole

19.6

When sufficient quantity of heat has been added to reach the boiling point of a solution, what happens to any additional heat added?

Additional heat is used to evaporate the liquid as the process is endothermic and requires continued input of energy.

Which atomic solid has the highest melting point? A) Cu B) Si C) Xe D) Fe E) not enough information

B) Si

Which intermolecular force is common to all polar molecules but NOT nonpolar molecules? A) dispersion forces B) dipole-dipole forces C) hydrogen bonding D) X-forces E) none of the above

B) dipole-dipole forces

Rank the compounds NH3, CH4, and PH3 in order of increasing boiling point.

CH4 < PH3 < NH3

Which substance is most likely to be miscible with water?

CHCl3

Which of the following statements is FALSE? A) Evaporation is an endothermic process. B) A puddle of water cools down as it evaporates. C) As a liquid is converted into a gas, the liquid absorbs heat. D) All of the above are true. E) None of the above are true.

D) All of the above are true.

Which compound will have the highest boiling point? A) Ch4 B) CH3CH3 C) CH3C(O)CH3 D) CH3CH2OH E) not enough information

D) CH3CH2OH

Which molecule below has hydrogen bonding? A) CH4 B) HCl C) H2 D) CH3CH2OH E) all of the above

D) CH3CH2OH

Which substance would be expected to have the highest boiling point? A) N2 B) O2 C) CO2 D) CO E) not enough information

D) CO

Which statement about surface tension is FALSE? A) Liquids tend to minimize their surface area. B) Molecules on the surface of the liquid have fewer molecules to interact with. C) Increased intermolecular forces increase surface tension. D) Items with densities lower than water will sink due to surface tension. E) All of the above statements are true.

D) Items with densities lower than water will sink due to surface tension.

Which substance below has dipole-dipole forces?

H2S