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

Transcription

1 Name: Class: Date: 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 H 2 O is called a(n) interaction. A) dipole-dipole B) ion-ion C) hydrogen bonding D) ion-dipole E) London dispersion force 4) Elemental iodine (I 2 ) is a solid at room temperature. What is the major attractive force that exists among different I 2 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) C 12 H 26 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 Br 2 and CCl 4? A) dispersion forces B) dispersion forces and ion-dipole C) dispersion forces and dipole-dipole D) dispersion forces, ion-dipole, and dipole-dipole E) None. Since both are gases at room temperature, they do not interact with each other. 1

2 Name: 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) I 2 B) Br 2 C) Cl 2 D) F 2 E) O 2 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 E) both independent of temperature 2

3 Name: 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) CH 3 CH 2 CH 3 B) CH 3 OCH 3 C) CH 3 Cl D) CH 3 CHO E) CH 3 CN 3

4 Name: 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 4

5 Name: 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 NH 3 experience only ion-dipole intermolecular forces? A) LiCl B) SiH 4 C) CH 3 I D) C 3 H 7 OH E) OCl 2 21) Which one of the following exhibits dipole-dipole attraction between molecules? A) NH 3 B) CF 4 C) C 10 H 22 D) O 2 E) SF 6 5

6 Name: 22) Which one of the following should have the lowest boiling point? A) CH 4 B) PCl 3 C) C 2 H 5 COOH D) LiCl E) Cl 2 S 23) What is the predominant intermolecular force in H 2 NNH 2? 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) CI 4 B) CF 4 C) CBr 4 D) CCl 4 E) CH 4 6

7 Name: 26) Based on the figure above, the boiling point of ethyl alcohol under an external pressure of 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 Br 2 (59 C; molecular mass 160 amu) is both dipole-dipole interactions and London dispersion forces. 7

8 Name: 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. 8

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: ) ANS: A PTS: 1 DIF: 2 REF: Page Ref: ) ANS: E PTS: 1 DIF: 2 REF: Page Ref: ) ANS: A PTS: 1 DIF: 3 REF: Page Ref: ) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 11.3 OBJ: 11.3; G2 8) ANS: A PTS: 1 DIF: 3 REF: Page Ref: 11.4 OBJ: 11.4; G3 9) ANS: A PTS: 1 DIF: 2 REF: Page Ref: 11.4 OBJ: 11.4; G2 10) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 11.5 OBJ: 11.5, 11.6; G2 11) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 11.6 OBJ: 11.6; G2 12) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 11.7 OBJ: 11.7; G2 13) ANS: A PTS: 1 DIF: 5 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 15) ANS: A PTS: 1 DIF: 1 REF: Page Ref: 11.4 OBJ: 11.4; 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 19) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 11.7 OBJ: 11.7; G2 20) ANS: A PTS: 1 DIF: 2 REF: Page Ref: ) ANS: A PTS: 1 DIF: 3 REF: Page Ref:

10 22) ANS: A PTS: 1 DIF: 3 REF: Page Ref: ) ANS: A PTS: 1 DIF: 2 REF: Page Ref: ) 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: ) ANS: sublimation PTS: 1 DIF: 1 REF: Page Ref: 11.4 OBJ: 11.4; G2 4) ANS: cholesteryl benzoate PTS: 1 DIF: 2 REF: Page Ref: 11.7 OBJ: 11.7; G2 TRUE/FALSE 1) ANS: F PTS: 1 DIF: 2 REF: Page Ref: ) ANS: T PTS: 1 DIF: 2 REF: Page Ref: ) ANS: T PTS: 1 DIF: 1 REF: Page Ref: 11.4 OBJ: 11.4; G2 4) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 11.6 OBJ: 11.5, 11.6; G2 5) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 11.7 OBJ: 11.7; G2 2

11 Unit 11 Practice [Answer Strip] ID : A _ C 7) _ C 11) _ B 1) _ A 8) _ B 12) _ C 2) _ A 13) _ C 17) _ D 3) _ E 14) _ A 15) _ E 18) _ A 4) _ C 19) _ A 9) _ E 5) _ A 20) _ B 10) _ A 6) _ A 16) _ A 21)

12 Unit 11 Practice [Answer Strip] ID : A _ A 22) _ T 2) _ T 3) _ A 23) _ T 4) _ T 5) _ B 24) _ D 25) _ E 26) _ F 1)