Unit 11 Practice. Name: Class: Date: Multiple Choice Identify the choice that best completes the statement or answers the question.

(1)

Unit 11 Practice

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 1) Crystalline solids ____.

A) have their particles arranged randomly B) have highly ordered structures

C) are usually very soft

D) exist only at high temperatures E) exist only at very low temperatures

____ 2) Together, liquids and solids constitute ____ phases of matter. A) the compressible

B) the fluid C) the condensed D) all of the E) the disordered

____ 3) When NaCl dissolves in water, aqueous Na+_{and Cl}–_{ions result. The force of attraction that exists between Na}+

and H2O is called a(n) ____ interaction.

A) dipole-dipole B) ion-ion

C) hydrogen bonding D) ion-dipole

E) London dispersion force

____ 4) Elemental iodine (I2) is a solid at room temperature. What is the major attractive force that exists among

different I2 molecules in the solid?

A) London dispersion forces B) dipole-dipole rejections C) ionic-dipole interactions D) covalent-ionic interactions E) dipole-dipole attractions

____ 5) C12H26 molecules are held together by ____.

A) ion-ion interactions B) hydrogen bonding C) ion-dipole interactions D) dipole-dipole interactions E) dispersion forces

____ 6) What type(s) of intermolecular forces exist between Br2 and CCl4?

A) dispersion forces

B) dispersion forces and ion-dipole C) dispersion forces and dipole-dipole

D) dispersion forces, ion-dipole, and dipole-dipole

(2)

____ 7) The shape of a liquid's meniscus is determined by ____. A) the viscosity of the liquid

B) the type of material the container is made of

C) the relative magnitudes of cohesive forces in the liquid and adhesive forces between the liquid and its container

D) the amount of hydrogen bonding in the liquid E) the volume of the liquid

____ 8)

The phase changes B  C and D  E are not associated with temperature increases because the heat energy is used up to ____.

A) increase distances between molecules B) break intramolecular bonds

C) rearrange atoms within molecules D) increase the velocity of molecules E) increase the density of the sample

____ 9) The substance with the largest heat of vaporization is ____. A) I2

B) Br2

C) Cl2

D) F2

E) O2

____ 10) Volatility and vapor pressure are ____. A) inversely proportional to one another B) directly proportional to one another C) not related

D) the same thing

(3)

____ 11) On a phase diagram, the melting point is the same as ____. A) the triple point

B) the critical point C) the freezing point D) the boiling point

E) the vapor-pressure curve

____ 12) Which of the following characteristics would prevent liquid crystal behavior? A) long axial structure

B) ionic configuration

C) carbon-carbon single bonds D) double bonding

E) polar groups

____ 13) In the ____ liquid crystalline phase, the component molecules exhibit only one dimensional ordering. A) nematic

B) smectic A C) smectic B D) smectic C E) cholesteric

____ 14) Based on molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point?

A) CH3CH2CH3

B) CH3OCH3

C) CH3Cl

D) CH3CHO

(4)

____ 15) The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the ____ segment corresponds to the heat capacity of the solid.

A) AB B) BC C) CD D) DE E) EF

____ 16) On the phase diagram shown above, the coordinates of point ____ correspond to the triple point. A) A

B) B C) C D) D E) E

(5)

____ 17) The phase diagram of a substance is shown above. The area labeled ____ indicates the gas phase for the substance. A) w B) x C) y D) z E) y and z

____ 18) According to the phase diagram shown above, the normal melting point of this substance is ____ °C. A) –13

B) 10 C) 29 D) 38 E) 0

____ 19) Which type of liquid crystal is colored and changes color with temperature? A) nematic

B) smectic A C) cholesteric D) smectic B E) smectic C

____ 20) With what compound will NH3 experience only ion-dipole intermolecular forces?

A) LiCl B) SiH4

C) CH3I

D) C3H7OH

E) OCl2

____ 21) Which one of the following exhibits dipole-dipole attraction between molecules? A) NH3

B) CF4

C) C10H22

D) O2

(6)

____ 22) Which one of the following should have the lowest boiling point? A) CH4 B) PCl3 C) C2H5COOH D) LiCl E) Cl2S

____ 23) What is the predominant intermolecular force in H2NNH2?

A) hydrogen bonding B) ion-dipole attraction C) ionic bonding

D) dipole-dipole attraction E) London-dispersion forces

____ 24) The heat of fusion of water is 6.01 kJ/mol. The heat capacity of liquid water is 75.3 J/mol  K. The conversion of 50.0 g of ice at 0.00 °C to liquid water at 0.00°C requires ____ kJ of heat.

A) 6.01 B) 16.7 C) 75.3 D) 17.2

E) Insufficient data are given.

____ 25) Of the following, ____ is the least volatile. A) CI4

B) CF4

C) CBr4

D) CCl4

(7)

____ 26) Based on the figure above, the boiling point of ethyl alcohol under an external pressure of 0.658 atm is ____ °C. A) 20 B) 40 C) 60 D) 80 E) 70 Short Answer

1) In general, intramolecular forces determine the ________ properties of a substance and intermolecular forces determine its ________ properties.

2) London Dispersion Forces tend to ________ in strength with increasing molecular weight. 3) The direct conversion of a solid to a gas is called ________.

4) The initial discovery of a liquid crystal resulted from studies on what compound? True/False

Indicate whether the statement is true or false.

____ 1) The principal source of the difference in the normal boiling points of ICl (97 °C; molecular mass 162 amu) and Br2 (59 °C; molecular mass 160 amu) is both dipole-dipole interactions and London dispersion forces.

(8)

____ 2) The boiling points of normal hydrocarbons are higher than those of branched hydrocarbons of similar molecular weight because the London-dispersion forces between normal hydrocarbons are greater than those between branched hydrocarbons.

____ 3) Heats of vaporization are greater than heats of fusion.

____ 4) Under ordinary conditions, a substance will sublime rather than melt if its triple point occurs at a pressure above atmospheric pressure.

____ 5) Molecules containing only single bonds do not exhibit liquid-crystal behavior because free rotation can occur around single bonds making these molecules flexible.

(9)

Unit 11 Practice

Answer Section

MULTIPLE CHOICE

1) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 11.1 OBJ: G2

2) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 11.1 OBJ: G2

3) ANS: D PTS: 1 DIF: 2 REF: Page Ref: 11.2 OBJ: 11.2; G2

4) ANS: A PTS: 1 DIF: 2 REF: Page Ref: 11.2 OBJ: 11.2; G2

5) ANS: E PTS: 1 DIF: 2 REF: Page Ref: 11.2 OBJ: 11.2; G2

7) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 11.3 OBJ: 11.3; G2

10) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 11.5 OBJ: 11.5, 11.6; G2

12) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 11.7 OBJ: 11.7; G2

14) ANS: E PTS: 1 DIF: 3 REF: Page Ref: 11.2 OBJ: 11.2; G3

16) ANS: A PTS: 1 DIF: 2 REF: Page Ref: 11.6 OBJ: 11.5, 11.6; G3

17) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 11.6 OBJ: 11.5, 11.6; G3

18) ANS: E PTS: 1 DIF: 2 REF: Page Ref: 11.6 OBJ: 11.5, 11.6; G3

(10)

24) ANS: B PTS: 1 DIF: 4 REF: Page Ref: 11.4 OBJ: 11.4; G4

25) ANS: D PTS: 1 DIF: 2 REF: Page Ref: 11.5 OBJ: 11.5, 11.6; G2

26) ANS: E PTS: 1 DIF: 3 REF: Page Ref: 11.5 OBJ: 11.5, 11.6; G3

SHORT ANSWER 1) ANS:

chemical, physical

PTS: 1 DIF: 2 REF: Page Ref: 11.1 OBJ: G2

2) ANS: increase

PTS: 1 DIF: 1 REF: Page Ref: 11.2 OBJ: 11.2; G2

3) ANS: sublimation

4) ANS:

cholesteryl benzoate

TRUE/FALSE

1) ANS: F PTS: 1 DIF: 2 REF: Page Ref: 11.2 OBJ: 11.2; G2

2) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 11.2 OBJ: 11.2; G2

4) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 11.6 OBJ: 11.5, 11.6; G2

(11)

_____ 1)B _____ 2)C _____ 3)D _____ 4)A _____ 5)E _____ 6)A _____ 7)C _____ 8)A _____ 9)A _____ 10)B _____ 11)C _____ 12)B _____ 13)A _____ 14)E _____ 15)A _____ 16)A _____ 17)C _____ 18)E _____ 19)C _____ 20)A _____ 21)A

(12)

_____ 22)A _____ 23)A _____ 24)B _____ 25)D _____ 26)E _____ 1)F _____ 2)T _____ 3)T _____ 4)T _____ 5)T