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.

1.

2.

3.

____________________________________________________________________________

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.

____________________________________________________________________________

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

1.

2.

3.

____________________________________________________________________________

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. CH3CH2CH­3 <H2O <CH3OCH3 <CH3CH2OH

____________________________________________________________________________

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 × 103 kJ of energy from a caramel frappuccino coffee with whipped cream. If this energy is used to vaporize water at 100.0 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

____________________________________________________________________________

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 46.07 g/mol melting point –114°C

boiling point 78.4°C

ΔHfus 5.02 kJ/mol

ΔHvap 38.56 kJ/mol

Cs of CH3CH2OH(s) 0.97 J/g·°C

Cs of CH3CH2OH(l) 2.46 J/g·°C

Cs of CH3CH2OH(g) 0.95 J/g·°C

A. 30.2 kJ

B. 21.9 kJ

C. 2.18 x 104 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.

2.

____________________________________________________________________________

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/cm3?

A. 22.7 g/cm3

B. 3.83 ×10-14 g/cm3

C. 5.78 g/cm3

D. 8.15 ×1029 g/cm3

____________________________________________________________________________

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.

1.

2.

____________________________________________________________________________

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.

C. SO2 is an ionic solid.

D. Quartz (repeating SiO2 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. 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) 3 .

1.

2.

3.

____________________________________________________________________________

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.

2.

3.

____________________________________________________________________________

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

____________________________________________________________________________

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. 0.28 M

B. 0.070 M

C. 3.4 ×10-2 M

D. 0.68 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.

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. 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 0.250 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

____________________________________________________________________________

Question #: 26

What is the boiling point of a solution made by dissolving 0.250 g of carvone, C10H14O (150.212 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 (110.98 g/mol) in enough water to make 5.00 × 102 mL of solution.

A. 2.10 M

B. 1.89 M

C. 0.646 M

D. 9.26 x 10–4 M

____________________________________________________________________________

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 oC Report your answer with three significant figures. Do NOT include units in your answer.

1.

____________________________________________________________________________

Question #: 30

A 0.188 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. 94.1 g/mol

B. 7.89×10-3 g/mol

C. 9.53 g/mol

D. 636 g/mol

DRAFTDo Not Use Until Posted.

CHE 107 Spring 2017 Exam 1 - Confidential

Your Name: Your ID:

attachment_for_pubExamUID_lnxp114865613625571963XX_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. gas2. solid3. 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. 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.  CH3-CH2-CH3

B.   HO-CH2-CH2-OH

C.   H3C-O-CH3

lowest boiling point      1     <     2     <     3      highest boiling point

1. A2. C3. B

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. CH3CH2CH­3 <H2O <CH3OCH3 <CH3CH2OH

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 × 103 kJ of energy from a caramel frappuccino coffee with

whipped cream. If this energy is used to vaporize water at 100.0 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. 894

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

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 46.07 g/mol

melting point –114°C

boiling point 78.4°C

Hfus 5.02 kJ/mol

Hvap 38.56 kJ/mol

   

A. 30.2 kJ ✓B. 21.9 kJ

C. 2.18 x 104 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. fusion2. sublimation

Cs of CH3CH2OH(s) 0.97 J/g·°C

Cs of CH3CH2OH(l) 2.46 J/g·°C

Cs of CH3CH2OH(g) 0.95 J/g·°C

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/cm3?

✓A. 22.7 g/cm3

B. 3.83 ×10-14 g/cm3

C. 5.78 g/cm3

D. 8.15 ×1029 g/cm3

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.

1. 12. 3

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.

 

C. SO2 is an ionic solid.

 

✓D. Quartz (repeating SiO2 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. 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) 

    3    .

1. noble

2. mineral3. 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

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

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 CO2at 25°C?

A. 0.28 M

✓B. 0.070 M C. 3.4 ×10-2 M D. 0.68 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.

1. 96.0

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. 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 0.250 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. 21.1

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

Question #: 26

What is the boiling point of a solution made by dissolving 0.250 g of carvone, C10H14O

(150.212 g/mol), in 3.00 g of carbon tetrachloride. The boiling point of CCl4 is 76.7ºC and the Kbof CCl4 is 5.03ºC/m.

    1     ºC

Report your answer with three significant figures. Do NOT include units in your answer.

1. 79.5

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 (110.98 g/mol) in enough water to make 5.00 × 102 mL of solution.

A. 2.10 M

✓B. 1.89 M C. 0.646 M D. 9.26 x 10–4 M

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      oC

Report your answer with three significant figures. Do NOT include units in your answer.

1. -2.75|-2.74|-2.76|

Question #: 30

A 0.188 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. 94.1 g/mol

B. 7.89×10-3 g/mol C. 9.53 g/mol D. 636 g/mol