End-of Chapter Quiz 3

The reason that coastal climates are more moderate than inland climates primarily water's high __________. A) specific heat B) surface tension C) adhesion D) heat of vaporization

A) specific heat

A polar covalent bond between two atoms results from: A) two atoms that do not have similar electronegativities. B) whether the bond is single or not. C) the presence of two ions close to each other. D) the shape of the molecule that has the bond.

A) two atoms that do not have similar electronegativities.

Which of the following is a hydrophobic material? A) wax B) paper C) sugar D) table salt E) pasta

A) wax

What is the hydroxide ion concentration of the lake described in question 5? A) 10-10 M B) 10-7 M C) 10 M D) 10-14 M E) 10-4 M

A) 10-10 M

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake? A) 10-4 M B) 4.0 M C) 4% D) 104 M E) 10-10 M

A) 10-4 M

A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.) A) 10°C B) 50°C C) 5°C D) 100°C E) 1°C

A) 10°C

How does the polarity of water contribute to its ability to dissolve so many substances? A) Because it is polar, water's negatively charged oxygen atoms and positively charged hydrogen atoms are attracted to positively and negatively charged ions and molecules. B) Because it is polar, water forms ionic bonds with the ions in substances such as NaCl (salt). C) Natural water has a pH of approximately 5.6, which is slightly acidic. Acids can dissolve more substances than bases can D) Water's polarity allows it to form covalent bonds with many substances.

A) Because it is polar, water's negatively charged oxygen atoms and positively charged hydrogen atoms are attracted to positively and negatively charged ions and molecules.

Which of the following occurs because molecules of water are farther apart in ice than in liquid water? A) Ice floats. B) Ice is denser than liquid water. C) Ice expands when it melts. D) Ice vaporizes before liquid water does.

A) Ice floats.

Why are cell membranes composed primarily of hydrophobic molecules? A) In order to perform their function of separating the aqueous solutions outside cells from the aqueous solutions inside cells, cell membranes cannot be soluble in water. B) In order to maintain a proper pH, cell membranes must be hydrophobic. C) Cell membranes must be composed of polar molecules in order to interact with the aqueous solutions inside cells. D) Cell membranes must be hydrophobic in order to allow polar and charged molecules to enter and leave the cell.

A) In order to perform their function of separating the aqueous solutions outside cells from the aqueous solutions inside cells, cell membranes cannot be soluble in water.

Why is the increasing amount of carbon dioxide being taken up by the oceans a cause for concern? A) More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to a decrease in the concentration of carbonate ion (CO32-). B) More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to an increase in the concentration of carbonate ion (CO32-). C) There is no cause for concern. Carbonic acid (H2CO3) is an excellent buffer and will help keep the pH of seawater constant. D) The buffering action of carbonic acid (H2CO3) causes the pH of seawater to rise.

A) More carbon dioxide causes an increase in carbonic acid (H2CO3), which leads to a decrease in the concentration of carbonate ion (CO32-).

Adhesion is best described as which of the following? A) The clinging of one substance to another substance B) The process by which a crystalline lattice forms C) The process that contributes to the transport of water and dissolved nutrients in plants by causing water molecules to tug on other water molecules D) A property of water that helps moderate Earth's temperature

A) The clinging of one substance to another substance

A molecule that has all nonpolar covalent bonds would be __________. A) hydrophobic B) hydrophilic C) acidic D) basic (alkaline)

A) hydrophobic

What do cohesion, surface tension, and adhesion have in common with reference to water? A) All are produced by covalent bonding. B) All are properties related to hydrogen bonding. C) All are results of the structure of the hydrogen atom. D) All have to do with ionic interactions.

B) All are properties related to hydrogen bonding.

Which action would involve the greatest transfer of heat? A) Evaporating 1 g of water at 25°C B) Condensing 5 g of steam to liquid water C) Changing the temperature of 1 g of water from 10°C to 90°C D) Cooling 10 g of water from 80°C to 40°C

B) Condensing 5 g of steam to liquid water

You can fill a glass of water to just slightly above the rim without the water spilling over the glass. What property of water best explains this phenomenon? A) Its polarity B) Surface tension C) Adhesion D) None of the listed responses is correct.

B) Surface tension

Imagine that organisms consisted of 70-95% alcohol instead of 70-95% water. Alcohol's specific heat is about half that of water. How would living things be different? A) Living organisms would have to be much smaller. B) Systems for temperature regulation would have to be much more efficient. C) Organisms would be able to live in a much wider range of temperatures. D) Warm-blooded organisms would require less insulation such as fur or feathers.

B) Systems for temperature regulation would have to be much more efficient.

Water is a polar molecule. What does this statement mean? A) That water molecules are linear, like a pole B) That atoms in the molecule have partial charges as a result of unequal sharing of electrons in a covalent bond C) That the atoms in water have equal electronegativities D) That water is one of the many hydrophobic molecules

B) That atoms in the molecule have partial charges as a result of unequal sharing of electrons in a covalent bond

The phenomenon responsible for maintaining the upward movement of water through vessels in a tree is __________. A) hydration shells B) cohesion C) specific heat D) surface tension

B) cohesion

Adding acid tends to __________ of a solution. A) increase the hydrogen ion concentration and raise the pH B) increase the hydrogen ion concentration and lower the pH C) decrease the hydrogen ion concentration and lower the pH D) decrease the hydrogen ion concentration and raise the pH

B) increase the hydrogen ion concentration and lower the pH

The absorption of human-generated CO2 by the oceans __________. A) reduces the carbonate ion concentration in the oceans and threatens calcifying organisms in marine ecosystems B) increases the hydrogen ion concentration in the oceans but decreases the carbonate ion concentration and threatens the livability of the oceans for organisms that produce calcium carbonate shells C) increases the oceans' acidity and pH D)increases the oceanic concentration of carbonic acid

B) increases the hydrogen ion concentration in the oceans but decreases the carbonate ion concentration and threatens the livability of the oceans for organisms that produce calcium carbonate shells

Adding a base tends to __________ of a solution. A) lower the hydrogen ion concentration and lower the pH B) lower the hydrogen ion concentration and increase the pH C)increase the hydrogen ion concentration and lower the pH D) increase the hydrogen ion concentration and increase the pH

B) lower the hydrogen ion concentration and increase the pH

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their A) mass in daltons B) number of molecules. C) number of atoms. D) mass in grams. E) volume.

B) number of molecules.

Water is a very versatile solvent because water molecules are __________. A) hydrophobic B) polar C) nonpolar D) ionic

B) polar

A glass of grapefruit juice, at pH 3, contains __________ H+ as a glass of tomato juice, at pH 4. A) one-tenth as much B) ten times as much C) half as much D) twice as much

B) ten times as much

Water has __________ than other liquids such as ethanol, reflecting its capacity to absorb large amounts of heat. A) a lower heat of vaporization B) a lower capacity for forming hydrogen bonds C) lower specific heat D) a higher boiling point

D) a higher boiling point

A substance that minimizes changes in the concentration of H+ and OH- in a solution is a __________. A) strong acid B) NaCl C) hydrophobic molecule D) buffer

D) buffer

A solution at pH 6 contains __________ than the same amount of solution at pH 8. A) 4 times more H+ B) 4 times less H+ C) 100 times more H+ D) 2 times more H+

C) 100 times more H+

Which of the following statements helps to explain why water molecules form hydrogen bonds? A) There is a partial negative charge on each hydrogen atom and two partial positive charges on the oxygen atom in a water molecule. B ) Water is an electronegative molecule. C) Attractions form between opposite partial charges. D) The electrons spend more time around the hydrogen atoms because hydrogen is more electronegative than oxygen.

C) Attractions form between opposite partial charges.

Which of the following dissociations is that of an acid? A) H2O → H+ + OH- B) NH3 + H+ → NH4+ C) HF → H+ + F- D) NaOH → Na+ + OH-

C) HF → H+ + F-

What are nonpolar molecules that cluster away from water molecules called? A) Hydrophilic B) Ionic C) Hydrophobic D) None of the listed responses is correct.

C) Hydrophobic

Which of the following accurately relates the emergent properties of water to the effects of global warming in the Arctic? A) Although it is feared that sea ice around Alaska and northern Canada may be greatly reduced by atmospheric warming, the high specific heat of water has so far buffered these sea ice communities from significant impacts. B) An increase in water temperature due to global warming will cause the sea ice formed in the Arctic to be denser and less buoyant. C) Ice floats because it is less dense than liquid water; floating ice insulates water below and provides a habitat for some species. The significant increase in Arctic air temperature over the past 50 years is causing a reduction in sea ice, compromising these beneficial effects of sea ice. D) Although a significant increase of air temperature has occurred in the Arctic over the past 50 years, the specific heat of water has thus far buffered against any significant increases in the Arctic ocean temperatures.

C) Ice floats because it is less dense than liquid water; floating ice insulates water below and provides a habitat for some species. The significant increase in Arctic air temperature over the past 50 years is causing a reduction in sea ice, compromising these beneficial effects of sea ice.

In a group of water molecules, hydrogen bonds form between which of the following? A) The hydrogen atoms in a single water molecule B) The oxygen atoms in different water molecules C) The oxygen atom in one water molecule and a hydrogen atom in another water molecule D) Two hydrogen atoms in different water molecules

C) The oxygen atom in one water molecule and a hydrogen atom in another water molecule

The ability of water molecules to form hydrogen bonds with other water molecules and water's ability to dissolve substances that have charges or partial charges are __________. A) due to water's partial charges and low molecular mass, respectively B) both caused by water's two electron shells C) both caused by water's partial charges D) both caused by water's ability to form covalent bonds with hydrophobic substances

C) both caused by water's partial charges

Electronegativity is: A) the repulsion of electrons in one atom for electrons in another atom. B) the negative charge surrounding the nucleus of an atom. C) the attraction of an atom for the electrons in a covalent bond. D) the number of electrons in the outermost electron shell.

C) the attraction of an atom for the electrons in a covalent bond.

The partial charges on a water molecule occur because of __________. A) widespread ionization B) covalent bonding C) the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule D) the achievement of a stable configuration by one atom of a bond but not by the other partner

C) the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule

Sweating has a cooling effect because of water's high __________. A) surface tension B) specific heat C) buffering capacity D) heat of vaporization

D) heat of vaporization

A mole of ethyl alcohol weighs 46 g. How many grams of ethyl alcohol are needed to produce 1 L of a 2-millimolar (2 mM) solution? A) 0.92 g B) 9.2 g C) 92 g D) 0.092 g

D) 0.092 g

Cells are surrounded by water, with which they are mostly filled. Which of the following occurs as a result? A) A variety of nutrient molecules is readily available as dissolved solutes. B) Waste products produced by cell metabolism can be easily removed. C) The temperature of living things tends to change relatively slowly. D) All of the listed responses are correct.

D) All of the listed responses are correct.

If water were not a polar molecule, how would the effects of climatic warming differ from those currently observed or predicted to occur in the future? A) If water molecules were nonpolar, then water vapor would be less effective as a greenhouse gas, and the effects of global warming would be less extreme. B) If water were nonpolar, the effects on global warming would be only slightly worse because there are other polar molecules that can moderate climate as water does. C) The effects would be worse because a loss of the polar molecular structure would lead to a greater amount of heat absorbed by water molecules and, thus, an increase in its specific heat. D) The effects would be drastically worse because the loss of the polar nature of water would greatly reduce its specific heat and its ability to moderate temperature.

D) The effects would be drastically worse because the loss of the polar nature of water would greatly reduce its specific heat and its ability to moderate temperature.

An acid is __________. A) any compound with a pH B) a material that resists changes in the pH of a solution C) any compound that accepts hydrogen ions D) a compound that donates hydrogen ions to a solution

D) a compound that donates hydrogen ions to a solution

The tendency of water molecules to stay close to each other as a result of hydrogen bonding __________. A) provides the surface tension that allows small animals to move across a water surface B) helps to keep water moving through the vessels in a tree trunk C) is called cohesion D) is called cohesion, acts to moderate temperature, provides the surface tension that allows small animals to move across a water surface, and helps to keep water moving through the vessels in a tree trunk

D) is called cohesion, acts to moderate temperature, provides the surface tension that allows small animals to move across a water surface, and helps to keep water moving through the vessels in a tree trunk

Sucrose has a molecular mass of 342 daltons. To make a 2-molar (2 M) solution of sucrose, __________. A) stir 684 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 2 L B) stir 684 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 0.5 L C) stir 342 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution to 1 L D) stir 342 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 0.5 L

D) stir 342 g of sucrose in water to dissolve the sugar, and then add enough water to bring the total volume of the solution up to 0.5 L

The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as __________. A) surface tension B) the specific heat of that substance C) 1 calorie D) the heat of vaporization of that substance

D) the heat of vaporization of that substance

The amount of heat required to change the temperature of 1 g of any substance by 1°C is defined as __________. A) 1 calorie B) 1 kilocalorie C) the heat of vaporization of that substance D) the specific heat of that substance

D) the specific heat of that substance