CHE 107 Spring 2017 Exam 1

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1 CHE 107 Spring 2017 Exam 1 Your Name: Your ID: Question #: 1 Identify the physical state of matter (solid, liquid, gas) that best fits the characteristics described in the following statements. Use each physical state one time only. A 1 has an indefinite shape and weak intermolecular forces A 2 has a definite volume and strong intermolecular forces. A 3 has an indefinite shape and moderate intermolecular forces Question #: 2 Given the following information, which statement is true? A. Ethanol has dispersion forces while dimethyl ether does not. B. Dimethyl ether has hydrogen bonding while ethanol does not. C. Neither ethanol nor dimethyl ether has dipole-dipole interactions. D. The sum of the intermolecular forces in ethanol are greater than those in dimethyl ether.

2 Question #: 3 Rank the following in order from lowest to highest boiling point. A. CH3-CH2-CH3 B. HO-CH2-CH2-OH C. H3C-O-CH3 lowest boiling point 1 < 2 < 3 highest boiling point Question #: 4 Rank the following four compounds in order from lowest to highest surface tension. CH3OCH3, CH3CH2CH3, H2O, CH3CH2OH A. CH3OCH3 <H2O <CH3CH2CH3 <CH3CH2OH B. CH3CH2CH3 <CH3OCH3 <CH3CH2OH <H2O C. CH3OCH3 <CH3CH2CH3 <H2O <CH3CH2OH D. CH3CH2CH 3 <H2O <CH3OCH3 <CH3CH2OH

3 Question #: 5 Select the two choices below where the applied process will increase the rate of vaporization of the liquid. A. A beaker of water is spilled on the floor. B. A beaker of water is cooled from 50 C to 22 C. C. Water is poured from a conical flask to a volumetric flask. D. The water in a beaker is poured out and replaced with acetone (Lewis structure below).

Question #: 6 The human body obtains 2.02 10 3 kj of energy from a caramel frappuccino coffee with whipped cream. If this energy is used to vaporize water at 100.

4 Question #: 6 The human body obtains kj of energy from a caramel frappuccino coffee with whipped cream. If this energy is used to vaporize water at ºC, how many ml of water could be vaporized? The ΔHvap of water is 40.7 kj/mol. Assume the density of water is 1.00 g/ml. 1 ml Report your answer with three significant figures. Do NOT include units in your answer. 1. Question #: 7 Benzyl acetate, C9H10O2, is a volatile compound associated with the aroma of strawberries. If the normal boiling point of benzyl acetate is 212 C, what is the boiling point when the pressure is lowered to 270. torr? ΔHvap = 55.5 kj/mol A. 156 C B. 178 C C. 197 C D. 224 C

5 Question #: 8 How much energy is required to convert 15.4 g of solid ethanol, CH3CH2OH(s), at 114 C, to gaseous ethanol, CH3CH2OH(g), at 78.4 C? molar mass CH3CH2OH melting point boiling point ΔHfus ΔHvap Cs of CH3CH2OH(s) Cs of CH3CH2OH(l) Cs of CH3CH2OH(g) g/mol 114 C 78.4 C 5.02 kj/mol kj/mol 0.97 J/g C 2.46 J/g C 0.95 J/g C A kj B kj C x 10 4 kj D. 132 kj

6 Question #: 9 The phase change that occurs moving in a straight line from point B to point C is 1. [freezing, fusion, sublimation, vaporization] The phase change that occurs moving in a straight line from point A to point D is 2. [condensation, deposition, fusion, sublimation] 1. 2.

7 Question #: 10 Iridium crystallizes in a face-centered cubic unit cell, as shown below, with an edge length of 383 pm. What is the density of Ir in g/cm 3? A g/cm 3 B g/cm 3 C g/cm 3 D g/cm 3

8 Question #: 11 A superalloy used in jet engines for its strength crystallizes as shown below, where the dark red spheres on the corners represent Al and the light gray spheres on the faces represent Ni. In this unit cell, there are 1 Al atom(s) and 2 Ni atom(s). Use whole numbers e.g., 1, 2, etc., for your answers

9 Question #: 12 Which crystalline solid is accurately identified? Scroll down, if needed, to see all four choices. A. CaF2 is a molecular solid. B. Diamond (repeating carbon tetrahedra) is a metallic solid.

10 C. SO2 is an ionic solid. D. Quartz (repeating SiO2 tetrahedra) is a network covalent atomic solid.

11 Question #: 13 Select the two options that complete the statement below. Metals are good conductors of electricity because A. metallic bonds are directional. B. their electrons are delocalized over the entire metal crystal. C. their valence and conduction bands are energetically continuous. D. they are held together by ionic bonds. Question #: 14 Fill in the blanks with the following choices: mineral, noble, ore. Each choice will be used only once. Only a few 1 metals occur naturally as elements, including nickel, copper, palladium, silver, platinum, and gold. Most of the rest of metals occur naturally in positive oxidation states within 2 deposits, or homogeneous, crystalline inorganic solids. A rock that contains a high concentration of a specific crystalline inorganic solid is called a(n) Question #: 15 Fill in the blanks with A, B, or C to match the figures with the type of material they represent. 1 Insulator 2 Conductor 3 Semiconductor

12 Question #: 16 Which one of the following acts as a n-type semiconductor? A. silicon doped with gallium B. arsenic doped with gallium C. germanium doped with phosphorous D. phosphorous doped with arsenic Question #: 17 Given that ΔHsolution = ΔHmix + ΔHsolute + ΔHsolvent which set of conditions prevents a solution from forming? A. ΔHmix >ΔHsolute + ΔHsolvent and ΔHsolution is large and negative B. ΔHmix > ΔHsolute + ΔHsolvent and ΔHsolution is small and negative C. ΔHmix < ΔHsolute + ΔHsolvent and ΔHsolution is large and positive D. ΔHmix < ΔHsolute + ΔHsolvent and ΔHsolution is small and positive Question #: 18 Which of the following is miscible with carbon tetrachloride, CCl4? A. H2O B. toluene, C7H8 C. acetone, CH3COCH3 D. methanol, CH3OH

13 Question #: 19 What happens when 25.0 g of KCl is added to 50.0 g of water 40.0 C? A. All 25.0 g of KCl dissolves, resulting in an unsaturated solution. B. All 25.0 g of KCl dissolves, resulting in a saturated solution. C. All 25.0 g of KCl dissolves, resulting in a supersaturated solution. D. A portion of the 25.0 g of KCl dissolves, resulting in a saturated solution with KCl(s) remaining. Question #: 20 Soft drinks are bottled with a partial pressure of CO2 of 4.0 atm over the liquid at 25 C, where the solubility of CO2 is 0.14 M. What is the solubility of CO2 if the bottles are packaged with a partial pressure of 2.0 atm of CO2 at 25 C? A M B M C M D M

14 Question #: 21 What mass of water needs to be added to 32.0 g of NaCl to prepare a solution that is 25.0% NaCl by mass? 1 g water Report your answer with three significant figures. Do NOT include units in your answer. 1. Question #: 22 An artist prepares a 42.0% by mass Co3(PO4)2 (367 g/mol) aqueous solution to make the color known as "cobalt violet." What is the mole percent of cobalt(ii) phosphate in the mixture? A. 3.43% B. 8.44% C. 11.9% D %

15 Question #: 23 What is the molality of a 1.70 M NaCl (58.44 g/mol) solution with a density of g/ml? A m B m C m D m Question #: 24 Calculate the vapor pressure of a solution containing mol of a nonvolatile nonelectrolyte dissolved in 35.0 ml of water at 25 C. The vapor pressure of pure water at 25 C is 23.8 torr. Assume the density of water is 1.00 g/ml. 1 torr Report your answer with three significant figures. Do NOT include units in your answer. 1. Question #: 25 An ideal solution is created by combining 0.10 mol of benzene and 0.20 mol of toluene, both of which are volatile. The vapor pressure of pure benzene is 75 torr and of pure toluene is 22 torr at 20 C. What is the total vapor pressure above the solution at 20 C? A. 25 torr B. 12 torr C. 97 torr D. 40. torr

16 Question #: 26 What is the boiling point of a solution made by dissolving g of carvone, C10H14O ( g/mol), in 3.00 g of carbon tetrachloride. The boiling point of CCl4 is 76.7ºC and the Kb of CCl4 is 5.03ºC/m. 1 ºC Report your answer with three significant figures. Do NOT include units in your answer. 1. Question #: 27 For which solute is the theoretical van't Hoff factor given? A. (NH4)3PO4, i = 4 B. CH3OH, i = 6 C. KNO3, i = 5 D. K2SO4, i = 4 Question #: 28 Determine the molar concentration of Cl ions in a solution made by dissolving 52.5 g CaCl2 ( g/mol) in enough water to make ml of solution. A M B M C M D x 10 4 M

17 Question #: 29 What is the freezing point of a solution containing 10.5 g of FeCl3 (162.2 g/mol) dissolved in 175 g of water? Kf (H2O) = 1.86 C/m 1 o C Report your answer with three significant figures. Do NOT include units in your answer. 1. Question #: 30 A g sample of a nonelectrolyte compound was isolated from a throat lozenge and dissolved in enough water to make 10.0 ml of solution at 25.0 C. The osmotic pressure of the resulting solution was 4.89 atm. What is the molar mass of the compound? A g/mol B g/mol C g/mol D. 636 g/mol

DRAFT Do Not Use Until Posted. CHE 107 Spring 2017 Exam 1 - Confidential Your Name: Your ID: attachment_for_pubexamuid_lnxp114865613625571963xx_157.

18 DRAFT Do Not Use Until Posted. CHE 107 Spring 2017 Exam 1 - Confidential Your Name: Your ID: attachment_for_pubexamuid_lnxp xx_157.jpg Question #: 1 Identify the physical state of matter (solid, liquid, gas) that best fits the characteristics described in the following statements. Use each physical state one time only. A 1 has an indefinite shape and weak intermolecular forces A 2 has a definite volume and strong intermolecular forces. A 3 has an indefinite shape and moderate intermolecular forces. 1. gas 2. solid 3. liquid Question #: 2

Given the following information, which statement is true? A. Ethanol has dispersion forces while dimethyl ether does not. B. Dimethyl ether has hydrogen bonding while ethanol does not. C.

19 Given the following information, which statement is true? A. Ethanol has dispersion forces while dimethyl ether does not. B. Dimethyl ether has hydrogen bonding while ethanol does not. C. Neither ethanol nor dimethyl ether has dipole-dipole interactions. D. The sum of the intermolecular forces in ethanol are greater than those in dimethyl ether. Question #: 3 Rank the following in order from lowest to highest boiling point. A. CH 3 -CH 2 -CH3 B. HO-CH 2 -CH 2 -OH C. H 3 C-O-CH 3 lowest boiling point 1 < 2 < 3 highest boiling point 1. A 2. C 3. B Question #: 4 Rank the following four compounds in order from lowest to highest surface tension. CH 3 OCH 3, CH 3 CH 2 CH 3, H 2 O, CH 3 CH 2 OH A. CH 3 OCH 3 <H 2 O <CH 3 CH 2 CH 3 <CH 3 CH 2 OH B. CH 3 CH 2 CH 3 <CH 3 OCH 3 <CH 3 CH 2 OH <H 2 O C. CH 3 OCH 3 <CH 3 CH 2 CH 3 <H 2 O <CH 3 CH 2 OH

20 D. CH 3 CH 2 CH 3 <H 2 O <CH 3 OCH 3 <CH 3 CH 2 OH Question #: 5 Select the two choices below where the applied process will increase the rate of vaporization of the liquid. A. A beaker of water is spilled on the floor. B. A beaker of water is cooled from 50 C to 22 C. C. Water is poured from a conical flask to a volumetric flask. D. The water in a beaker is poured out and replaced with acetone (Lewis structure below). Question #: 6 The human body obtains kj of energy from a caramel frappuccino coffee with whipped cream. If this energy is used to vaporize water at ºC, how many ml of water could be vaporized? The ΔH vap of water is 40.7 kj/mol. Assume the density of water is 1.00

21 g/ml. 1 ml Report your answer with three significant figures. Do NOT include units in your answer Question #: 7 Benzyl acetate, C 9 H 10 O 2, is a volatile compound associated with the aroma of strawberries. If the normal boiling point of benzyl acetate is 212 C, what is the boiling point when the pressure is lowered to 270. torr? ΔH vap = 55.5 kj/mol A. 156 C B. 178 C C. 197 C D. 224 C Question #: 8 How much energy is required to convert 15.4 g of solid ethanol, CH 3 CH 2 OH(s), at 114 C, to gaseous ethanol, CH 3 CH 2 OH(g), at 78.4 C? molar mass CH 3 CH 2 OH g/mol melting point 114 C boiling point 78.4 C H fus 5.02 kj/mol H vap kj/mol

22 C s of CH 3 CH 2 OH(s) C s of CH 3 CH 2 OH(l) C s of CH 3 CH 2 OH(g) 0.97 J/g C 2.46 J/g C 0.95 J/g C A kj B kj C x 10 4 kj D. 132 kj Question #: 9 The phase change that occurs moving in a straight line from point B to point C is 1. [freezing, fusion, sublimation, vaporization] The phase change that occurs moving in a straight line from point A to point D is 2. [condensation, deposition, fusion, sublimation] 1. fusion 2. sublimation

23 Question #: 10 Iridium crystallizes in a face-centered cubic unit cell, as shown below, with an edge length of 383 pm. What is the density of Ir in g/cm 3? A g/cm 3 B g/cm 3 C g/cm 3 D g/cm 3 Question #: 11 A superalloy used in jet engines for its strength crystallizes as shown below, where the dark red spheres on the corners represent Al and the light gray spheres on the faces represent Ni. In this unit cell, there are 1 Al atom(s) and 2 Ni atom(s). Use whole numbers e.g., 1, 2, etc., for your answers.

24 Question #: 12 Which crystalline solid is accurately identified? Scroll down, if needed, to see all four choices. A. CaF 2 is a molecular solid. B. Diamond (repeating carbon tetrahedra) is a metallic solid.

25 C. SO 2 is an ionic solid. D. Quartz (repeating SiO 2 tetrahedra) is a network covalent atomic solid.

Question #: 13 Select the two options that complete the statement below. Metals are good conductors of electricity because A. metallic bonds are directional. B.

26 Question #: 13 Select the two options that complete the statement below. Metals are good conductors of electricity because A. metallic bonds are directional. B. their electrons are delocalized over the entire metal crystal. C. their valence and conduction bands are energetically continuous. D. they are held together by ionic bonds. Question #: 14 Fill in the blanks with the following choices: mineral, noble, ore. Each choice will be used only once. Only a few 1 metals occur naturally as elements, including nickel, copper, palladium, silver, platinum, and gold. Most of the rest of metals occur naturally in positive oxidation states within 2 deposits, or homogeneous, crystalline inorganic solids. A rock that contains a high concentration of a specific crystalline inorganic solid is called a(n) noble

2. mineral 3. ore Question #: 15 Fill in the blanks with A, B, or C to match the figures with the type of material they represent. 1 Insulator 2 Conductor 3 Semiconductor 1. C c C. c. 2. A A. a a. 3. B B.

27 2. mineral 3. ore Question #: 15 Fill in the blanks with A, B, or C to match the figures with the type of material they represent. 1 Insulator 2 Conductor 3 Semiconductor 1. C c C. c. 2. A A. a a. 3. B B. b b. Question #: 16 Which one of the following acts as a n-type semiconductor? A. silicon doped with gallium B. arsenic doped with gallium C. germanium doped with phosphorous D. phosphorous doped with arsenic Question #: 17 Given that ΔH solution = ΔH mix + ΔH solute + ΔH solvent which set of conditions prevents a solution from forming? A. ΔH mix >ΔH solute + ΔH solvent and ΔH solution is large and negative B. ΔH mix > ΔH solute + ΔH solvent and ΔH solution is small and negative

28 C. ΔH mix < ΔH solute + ΔH solvent and ΔH solution is large and positive D. ΔH mix < ΔH solute + ΔH solvent and ΔH solution is small and positive Question #: 18 Which of the following is miscible with carbon tetrachloride, CCl 4? A. H 2 O B. toluene, C 7 H 8 C. acetone, CH 3 COCH 3 D. methanol, CH 3 OH Question #: 19 What happens when 25.0 g of KCl is added to 50.0 g of water 40.0 C? A. All 25.0 g of KCl dissolves, resulting in an unsaturated solution. B. All 25.0 g of KCl dissolves, resulting in a saturated solution. C. All 25.0 g of KCl dissolves, resulting in a supersaturated solution.

29 D. A portion of the 25.0 g of KCl dissolves, resulting in a saturated solution with KCl(s) remaining. Question #: 20 Soft drinks are bottled with a partial pressure of CO 2 of 4.0 atm over the liquid at 25 C, where the solubility of CO 2 is 0.14 M. What is the solubility of CO 2 if the bottles are packaged with a partial pressure of 2.0 atm of CO 2 at 25 C? A M B M C M D M Question #: 21 What mass of water needs to be added to 32.0 g of NaCl to prepare a solution that is 25.0% NaCl by mass? 1 g water Report your answer with three significant figures. Do NOT include units in your answer Question #: 22 An artist prepares a 42.0% by mass Co 3 (PO 4 ) 2 (367 g/mol) aqueous solution to make the color known as "cobalt violet." What is the mole percent of cobalt(ii) phosphate in the mixture?

A. 3.43% B. 8.44% C. 11.9% D. 0.135% Question #: 23 What is the molality of a 1.70 M NaCl (58.44 g/mol) solution with a density of 1.069 g/ml? A. 3.40 m B. 1.59 m C. 1.75 m D. 1.70 m Question #: 24 Calculate the vapor pressure of a solution containing 0.

30 A. 3.43% B. 8.44% C. 11.9% D % Question #: 23 What is the molality of a 1.70 M NaCl (58.44 g/mol) solution with a density of g/ml? A m B m C m D m Question #: 24 Calculate the vapor pressure of a solution containing mol of a nonvolatile nonelectrolyte dissolved in 35.0 ml of water at 25 C. The vapor pressure of pure water at 25 C is 23.8 torr. Assume the density of water is 1.00 g/ml. 1 torr Report your answer with three significant figures. Do NOT include units in your answer.

31 Question #: 25 An ideal solution is created by combining 0.10 mol of benzene and 0.20 mol of toluene, both of which are volatile. The vapor pressure of pure benzene is 75 torr and of pure toluene is 22 torr at 20 C. What is the total vapor pressure above the solution at 20 C? A. 25 torr B. 12 torr C. 97 torr D. 40. torr Question #: 26 What is the boiling point of a solution made by dissolving g of carvone, C 10 H 14 O ( g/mol), in 3.00 g of carbon tetrachloride. The boiling point of CCl 4 is 76.7ºC and the K b of CCl 4 is 5.03ºC/m. 1 ºC Report your answer with three significant figures. Do NOT include units in your answer Question #: 27 For which solute is the theoretical van't Hoff factor given? A. (NH 4 ) 3 PO 4, i = 4 B. CH 3 OH, i = 6 C. KNO 3, i = 5 D. K 2 SO 4, i = 4 Question #: 28

32 Determine the molar concentration of Cl ions in a solution made by dissolving 52.5 g CaCl 2 ( g/mol) in enough water to make ml of solution. A M B M C M D x 10 4 M Question #: 29 What is the freezing point of a solution containing 10.5 g of FeCl 3 (162.2 g/mol) dissolved in 175 g of water? K f (H 2 O) = 1.86 C/m 1 o C Report your answer with three significant figures. Do NOT include units in your answer Question #: 30 A g sample of a nonelectrolyte compound was isolated from a throat lozenge and dissolved in enough water to make 10.0 ml of solution at 25.0 C. The osmotic pressure of the resulting solution was 4.89 atm. What is the molar mass of the compound? A g/mol B g/mol C g/mol D. 636 g/mol

CHE 107 Fall 2017 Exam 1

CHE 107 Fall 2017 Exam 1 Your Name: Your ID: Question #: 1 Fill in the blanks with the letter corresponding to the correct term. Use each term only once. Your response for each one should be a single letter.