Deck 8: The Unusual Nature of Water

Question 1

The shape of a water molecule can be described as

A) trigonal planar.
B) tetrahedral.
C) linear.
D) bent.
E) square.

Answer 1

D

Question 2

The water molecule has how many bonding, and how many lone pairs of electrons?

A) two bonding and two lone pairs
B) one bonding and two lone pairs
C) two bonding and one lone pair
D) two bonding and no lone pairs
E) one bonding and three lone pairs

Answer 2

A

Question 3

What is the H-O-H angle in the water molecule?

A) 109.5°
B) 104.5°
C) 120°
D) 180°
E) 90.5°

Answer 3

B

Question 4

Partial charges are symbolized using the Greek letter

A) α.
B) β.
C) γ.
D) δ.
E) ε.

Question 5

Choose the most polar molecule.

A) H₂
B) F₂
C) Br₂
D) CH₄
E) HF

Question 6

A dipole is created by

A) hydrogen bonding.
B) lone electron pairs.
C) separation of charge.
D) chain branching.
E) intermolecular forces.

Question 7

Choose the molecule that is nonpolar.

A) CH₂Cl₂
B) H₂O
C) HCl
D) F₂
E) NH₃

Question 8

How many of the following molecules are polar?
H₂ CO₂ NH₃ CO

A) none
B) 1
C) 2
D) 3
E) All

Question 9

How many of the following molecules are polar?
HF CH₄ PH₃ OF₂

A) none
B) 1
C) 2
D) 3
E) all

Question 10

The ability of an atom in a molecule to attract a shared pair of electrons is known as

A) electronegativity.
B) polarity.
C) hydrogen bonding.
D) covalency.
E) heat capacity.

Question 11

Electronegativity increases

A) from top to bottom within a group.
B) from left to right across a period.
C) with increasing atomic weight.
D) both A and B
E) none of the above

Question 12

The element having the highest electronegativity is

A) Fr.
B) He.
C) Ne.
D) O.

Question 13

Bond polarity has to do with a difference in

A) atomic weight.
B) molecular shape.
C) electronegativity.
D) valence electrons.
E) atomic size.

Question 14

Classify the P-H bond in terms of polarity. EN_P = 2.2, EN_H = 2.1

A) polar covalent
B) nonpolar covalent
C) ionic
D) Not enough information is provided.

Question 15

Classify the Na-S bond in terms of polarity. EN_Na= 0.9, EN_S = 2.6

A) polar covalent
B) nonpolar covalent
C) ionic
D) Not enough information is provided.

Question 16

Classify the C--O bond in terms of polarity. EN_C= 2.5, EN_O = 3.5

A) polar covalent
B) nonpolar covalent
C) ionic
D) Not enough information is provided.

Question 17

Classify the Li--F bond in terms of polarity. EN_Li= 1.0, EN_F = 4.0

A) polar covalent
B) nonpolar covalent
C) ionic
D) Not enough information is provided.

Question 18

Classify the S--H bond in terms of polarity. EN_H= 2.1, EN_S = 2.6

A) polar covalent
B) nonpolar covalent
C) ionic
D) Not enough information is provided.

Question 19

Choose the most polar bond.

A) C-H
B) O-H
C) N-H
D) B-H
E) P-H

Question 20

Choose the most polar bond.

A) C-H
B) C-O
C) C-S
D) C-Cl
E) C-F

Question 21

A hydrogen bond may form between a hydrogen atom of one molecule and which atom on a neighboring molecule?

A) fluorine
B) lithium
C) sulfur
D) phosphorus
E) none of the above

Question 22

The electrical attraction between a H atom in one molecule and a highly electronegative atom in another is called a(n)

A) bond dipole.
B) hydrogen bond.
C) intramolecular bond.
D) ionic bond.
E) polar covalent bond.

Question 23

Which molecule can participate in hydrogen bonding?

A) CH₄
B) HBr
C) H₂S
D) PH₃
E) CH₃OH

Question 24

Which molecule cannot participate in hydrogen bonding?

A) H₂O
B) NH₃
C) SiH₄
D) CH₃CH₂COOH
E) HF

Question 25

How many hydrogen bonds is each molecule of H₂O capable of forming?

A) one
B) two
C) three
D) four
E) variable

Question 26

Attractions between neighboring molecules are known as

A) ionic bonds.
B) nonpolar covalent bonds.
C) polar covalent bonds.
D) intramolecular bonds.
E) intermolecular bonds.

Question 27

The strength of a hydrogen bond is approximately _______ that of an O-H covalent bond.

A) 75%
B) 50%
C) 25%
D) 5%
E) the same as

Question 28

When frozen into ice, water molecules hydrogen bond to their neighbors in __________ geometry.

A) trigonal planar
B) square planar
C) tetrahedral
D) linear
E) octahedral

Question 29

The energy of motion, which increases with increasing temperature, is known as __________ energy.

A) kinetic
B) potential
C) mechanical
D) bond
E) internal

Question 30

Arrange the three phases of water in order of decreasing kinetic energy (highest to lowest).

A) solid > liquid > gas
B) gas > liquid > solid
C) liquid > solid > gas
D) liquid > gas > solid
E) has > solid > liquid

Question 31

Arrange the three phases of water in order of decreasing density (highest to lowest).

A) solid > liquid > gas
B) gas > liquid > solid
C) liquid > solid > gas
D) liquid > gas > solid
E) gas > solid > liquid

Question 32

Arrange the three molecules below in order of increasing boiling point (lowest to highest).
I) HOCH₂CH₂OH
II) CH₃CH₂OH
III) B(OH)₃

A) III < II < I
B) III < I < II
C) II < III < I
D) II < I < III
E) I < II < III

Question 33

Choose the molecule with the highest boiling point.

A) CH₃CHOCH₂CH₃
B) CH₃CH₂OH
C) CH₃CH₂COOH
D) HOCH₂C(OH)HCH₂OH
E) CH₃CH₂CH₂CH₂OH

Question 34

Water boils at 100 °C because of

A) periodic trends.
B) hydrogen bonding.
C) high density.
D) valence electrons.
E) electronegativity.

Question 35

The amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius is the

A) specific heat capacity.
B) boiling point.
C) density.
D) intermolecular bond.
E) bond energy.

Question 36

Which substance would you expect to exhibit the greatest rise in temperature when heated over the same electric burner for 15 minutes?

A) copper
B) iron
C) aluminum
D) gold
E) Not enough information is provided.

Question 37

Which substance would you expect to exhibit the lowest rise in temperature when heated over the same electric burner for 15 minutes?

A) copper
B) iron
C) aluminum
D) gold
E) ethanol

Question 38

For questions , refer to the following table.
$\begin{array}{lc}\hline \text { Substance } & \text { Specific Heat Capacity }\left(\mathrm{J} / \mathrm{g}{ }^{\circ} \mathrm{C}\right) \\\hline \text { Gold }(\mathrm{Au}) & 0.129 \\\text { Copper (Cu) } & 0.386 \\\text { Iron (Fe) } & 0.450 \\\text { Aluminum (Al) } & 0.900 \\\text { Ethanol }\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right) & 2.460 \\\hline\end{array}$

-Calculate the amount of heat energy required to raise the temperature of 26.5 g of aluminum from 25 °C to 40 °C.

A) 954 J
B) 358 J
C) 596 J
D) 179 J
E) 0.900 J

Question 39

For questions , refer to the following table.
$\begin{array}{lc}\hline \text { Substance } & \text { Specific Heat Capacity }\left(\mathrm{J} / \mathrm{g}{ }^{\circ} \mathrm{C}\right) \\\hline \text { Gold }(\mathrm{Au}) & 0.129 \\\text { Copper (Cu) } & 0.386 \\\text { Iron (Fe) } & 0.450 \\\text { Aluminum (Al) } & 0.900 \\\text { Ethanol }\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right) & 2.460 \\\hline\end{array}$

-Calculate the amount of heat energy required to raise the temperature of 136 g of copper from 15°C to 85 °C.

A) 700 J
B) 787 J
C) 2231 J
D) 4462 J
E) 3700 J

Question 40

For questions , refer to the following table.
$\begin{array}{lc}\hline \text { Substance } & \text { Specific Heat Capacity }\left(\mathrm{J} / \mathrm{g}{ }^{\circ} \mathrm{C}\right) \\\hline \text { Gold }(\mathrm{Au}) & 0.129 \\\text { Copper (Cu) } & 0.386 \\\text { Iron (Fe) } & 0.450 \\\text { Aluminum (Al) } & 0.900 \\\text { Ethanol }\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right) & 2.460 \\\hline\end{array}$

-Calculate the final temperature of an iron horseshoe weighing 397 g that is supplied with 25,000 J energy in a blacksmith's shop, starting at room temperature (25 °C).

A) 140 °C
B) 160 °C
C) 165 °C
D) 179 °C
E) 4.5 * 10⁶ °C

Question 41

For questions , refer to the following table.
$\begin{array}{lc}\hline \text { Substance } & \text { Specific Heat Capacity }\left(\mathrm{J} / \mathrm{g}{ }^{\circ} \mathrm{C}\right) \\\hline \text { Gold }(\mathrm{Au}) & 0.129 \\\text { Copper (Cu) } & 0.386 \\\text { Iron (Fe) } & 0.450 \\\text { Aluminum (Al) } & 0.900 \\\text { Ethanol }\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right) & 2.460 \\\hline\end{array}$

-A 176 g sample of ethanol was provided 30 kJ of heat energy. Afterwards, the temperature of the sample was found to be 75 °C. What was the initial temperature of the sample?

A) 74.3 °C
B) 69 °C
C) 6 °C
D) 144 °C
E) 81 °C

Question 42

For questions , refer to the following table.
$\begin{array}{lc}\hline \text { Substance } & \text { Specific Heat Capacity }\left(\mathrm{J} / \mathrm{g}{ }^{\circ} \mathrm{C}\right) \\\hline \text { Gold }(\mathrm{Au}) & 0.129 \\\text { Copper (Cu) } & 0.386 \\\text { Iron (Fe) } & 0.450 \\\text { Aluminum (Al) } & 0.900 \\\text { Ethanol }\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right) & 2.460 \\\hline\end{array}$

-A sample of an unknown metal is found to weigh 64 g, and when supplied with 100 J heat energy, the temperature of the metal rises from 25.0 °C to 37.1 °C. Identify the metal.

A) gold
B) copper
C) iron
D) aluminum
E) none of the above

Question 43

Choose the true statement:

A) Water has a lower heat capacity than most other liquids
B) The specific heat capacity is the ability of a substance to undergo a phase change at a given temperature.
C) While undergoing a phase change, a substance does not change its temperature.
D) The phase change from vapor to water is called boiling.
E) Water's heat capacity means that it changes temperature quickly on exposure to low amounts of heat energy.

Question 44

Which of these is another word for melting?

A) fusion
B) condensation
C) vaporization
D) denaturation
E) dissolution

Question 45

Choose the false statement.

A) The phase change from vapor to water is called condensation.
B) It takes more energy to melt a given sample of ice than to vaporize the same sample to steam.
C) Much of the energy used to melt a sample of ice is needed for breaking hydrogen bonds.
D) The process of ice melting absorbs heat energy from its surroundings.

Question 46

The amount of energy required to cause a phase change is called

A) bond energy.
B) heat capacity.
C) intermolecular energy.
D) heat of reaction.
E) latent heat.

Question 47

Name three unusual properties of water.

Question 48

What is it about the molecular structure of water that allows it to behave so differently from other, similar liquids?

Question 49

When ice crystals form on a window pane in winter, is heat released or absorbed?

Question 50

When steam from a bag of microwave popcorn hits a person's skin and turns to liquid water, is heat released or absorbed?

Question 51

When ice melts, covalent bonds within water molecules are breaking.

Question 52

Would you expect the boiling point of ethanol, CH₃CH₂OH, to be higher or lower than that of water? Explain your answer.

Question 53

Which would be heavier, one liter of water or one liter of ice?

Question 54

Is the process of freezing endo- or exothermic?

Question 55

Is the process of vaporization endo- or exothermic?

Question 56

A bottle of methanol is left uncapped next to an equal-volume bottle of water. Both liquids start at the same level. After a few days, which bottle would you expect to have a lower level of liquid?