Biology Chapter 3 Pearson Practice Test

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

B. increase the hydrogen ion concentration and lower the pH

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

A. 0.092 g

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. Cell membranes must be composed of polar molecules in order to interact with the aqueous solutions inside cells. C. In order to maintain a proper pH, cell membranes must be hydrophobic. 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.

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 -In the case of water, the oxygen is slightly negative, and the hydrogen atoms are slightly positive.

A molecule that has all nonpolar covalent bonds would be __________.

hydrophobic

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. Cooling 10 g of water from 80°C to 40°C D. Changing the temperature of 1 g of water from 10°C to 90°C

B. Condensing 5 g of steam to liquid water

What are nonpolar molecules that cluster away from water molecules called?

hydrophobic

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

B. a compound that donates hydrogen ions to a solution -An acid donates hydrogen ions to a solution.

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-). -As seawater becomes more acidic, carbonate ion concentration decreases. The decrease in the availability of carbonate ion makes it more difficult for marine organisms to secrete calcium carbonate shells.

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

A. The clinging of one substance to another substance

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

A. a higher boiling point

Question 10:The phenomenon responsible for maintaining the upward movement of water through vessels in a tree is __________. A. cohesion B. specific heat C. surface tension D. hydration shells

A. cohesion -Cohesion is a consequence of hydrogen bonding between water molecules.

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

A. polar -Because molecules of polar solvents have a positive and a negative pole, polar solvents are excellent solvents for ions and for other polar materials.

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

A. ten times as much -The pH scale is a base-10 logarithmic scale. The change from any pH value to the next smaller value represents a tenfold increase in the hydrogen ion concentration.

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

A. the specific heat of that substance

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

B. the unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule -Because oxygen is more electronegative than hydrogen, electrons of the polar bond spend more time closer to the oxygen atom, resulting in a slight negative charge on the oxygen atom and slight positive charges on the hydrogen atoms.

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

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. Adhesion C. Surface tension D. None of the listed responses is correct.

C. Surface tension -Water has a greater surface tension, a measure of how difficult it is to break the surface of a liquid, than most other liquids.

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

C. Systems for temperature regulation would have to be much more efficient. -In order for living things to inhabit a wide range of environments, temperature regulation would need to be more efficient for a fluid with a lower specific heat.

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

C. heat of vaporization

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 oceanic concentration of carbonic acid C. 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 D. increases the oceans' acidity and pH

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

C. specific heat

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. the heat of vaporization of that substance D. 1 calorie

C. the heat of vaporization of that substance

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

D. 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. 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.

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

D. 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 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.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. 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.

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.

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

D. Ice floats.

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. 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. C. 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. 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. -A loss of the polar nature of water would equate to a loss in the ability to form hydrogen bonds. Breaking hydrogen bonds absorbs energy, which accounts for water's high specific heat and its ability to influence and moderate climate.

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

D. The oxygen atom in one water molecule and a hydrogen atom in another water molecule -The slightly negatively charged region of an oxygen atom of one water molecule is attracted to the slightly positively charged region of a hydrogen atom of 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 ability to form covalent bonds with hydrophobic substances C. both caused by water's two electron shells D. both caused by water's partial charges

D. both caused by water's partial charges -Two molecules of water are held together by a hydrogen bond formed between the slight positive charge of the hydrogen and the slight negative charge of the oxygen. Water is a very versatile solvent, a quality traced to the polarity of the water molecule.

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

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

D. lower the hydrogen ion concentration and increase the pH -A substance that reduces the hydrogen ion concentration is a base. Reducing the hydrogen ion concentration increases the pH.

A substance that minimizes changes in the concentration of H+ and OH- in a solution is a __________.

buffer