Bio chapter 3

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)9.2 g B)0.92 g C)0.092 g D)92 g

0.092 g

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

100 times more H+

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

Hydrophobic

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

hydrophobic

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

heat of vaporization

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

specific heat

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

All are properties related to hydrogen bonding.

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

All of the listed responses are correct.

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

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 action would involve the greatest transfer of heat? A)Cooling 10 g of water from 80°C to 40°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)Evaporating 1 g of water at 25°C

Condensing 5 g of steam to liquid water

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

HF → H+ + F-

Which of the following accurately relates the emergent properties of water to the effects of global warming in the Arctic? A)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. 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)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. D)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.

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.

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

Ice floats.

Why are cell membranes composed primarily of hydrophobic molecules? A)In order to maintain a proper pH, cell membranes must be hydrophobic. B)Cell membranes must be hydrophobic in order to allow polar and charged molecules to enter and leave the cell. C)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. D)Cell membranes must be composed of polar molecules in order to interact with the aqueous solutions inside cells.

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

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

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)Adhesion B)Its polarity C)Surface tension D)None of the listed responses is correct. right answer feedback:

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)Warm-blooded organisms would require less insulation such as fur or feathers. B)Systems for temperature regulation would have to be much more efficient. C)Living organisms would have to be much smaller. D)Organisms would be able to live in a much wider range of temperatures.

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

Water is a polar molecule. What does this statement mean? A)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 C)That the atoms in water have equal electronegativities D)That water molecules are linear, like a pole

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

Adhesion is best described as which of the following? A)A property of water that helps moderate Earth's temperature B)The clinging of one substance to another substance 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)The process by which a crystalline lattice forms

The clinging of one substance to another substance

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.

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.

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 atom in one water molecule and a hydrogen atom in another water molecule C)Two hydrogen atoms in different water molecules D)The oxygen atoms in different water molecules

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

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

a compound that donates hydrogen ions to a solution

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)a higher boiling point D)lower specific heat

a higher boiling point

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 ability to form covalent bonds with hydrophobic substances D)both caused by water's partial charges

both caused by water's partial charges

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

buffer

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

cohesion

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

increase the hydrogen ion concentration and lower the pH

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

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

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 is called cohesion C)is called cohesion, acts to moderate temperature, provides the D)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

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

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

lower the hydrogen ion concentration and increase the pH

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

polar

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 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 C)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 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

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

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

ten times as much

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

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)the heat of vaporization of that substance B)1 calorie C)the specific heat of that substance D)1 kilocalorie

the specific heat of that substance

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

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