Chapter 3 Practice quiz

An acid is a substance that A. contains hydrogen. B. forms covalent bonds with other substances. C. donates hydrogen ions to solutions. D. is a versatile solvent. E. removes hydrogen ions from solutions.

A

Most acid precipitation results from the combination of __________with water in the atmosphere, forming strong acids that fall with rain or snow. A. sulfur and nitrogen oxides B. carbon dioxide C. ozone D. buffers E. ammonium

A

Select the statement that best describes a buffer. A. Buffers accept hydrogen ions when they are in excess and donate hydrogen ions when they have been depleted. B. Buffers cause acidic solutions to become alkaline, and alkaline solutions to become acidic. C. Buffers completely prevent the pH of a solution from changing when an acid or base is added. D. Buffers stabilizes the pH of a solution by preventing acids or bases from dissociating. E. Buffered solutions are always neutral, with a pH of 7.

A

The phenomenon responsible for the maintenance of a column of water as it moves upward through a vessel is A. cohesion. B. specific heat C. kinetic energy. D. evaporation. E. latent heat.

A

Water is a polar molecule. This means that: A. the opposite ends of the molecule have opposite charges. B. water molecules are linear, like a pole. C. water is one of the many hydrophobic molecules. D. the atoms in water have electronegativites which are equal. E. all of the above

A

Which of the following solutions has the greater concentration of hydrogen ions (H+)? A. gastric juice at pH 2 B. vinegar at pH 3 C. tomatoes at pH 4 D. black coffee at pH 5 E. seawater at pH 8

A

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 raise the pH D. decrease the hydrogen ion concentration and lower the pH E. either increase or decrease the pH, depending on the original acidity

B

Assume that acid rain has lowered the pH of a particular lake to pH 5.0. What is the hydroxide ion concentration of this lake? A. 1 x 10-5 moles of hydroxide ion per liter of lake water B. 1 x 10-9 moles of hydroxide ion per liter of lake water C. 5.0 molar with regard to hydroxide ion concentration D. 9.0 molar with regard to hydroxide ion concentration E. Both B and D are correct.

B

At what temperature is water at its densest? A. 0oC B. 4oC C. 32o C D. 100o C E. 212o C

B

Glucose dissolves in water because it A. is an ionic molecule B. is a polar and forms many hydrogen bonds with the water molecules. C. has very reactive primary structure D. both A and B are true E. none of the above is correct

B

Ice is lighter and floats in water because it is a crystalline structure held together by A. ionic bonds only. B. hydrogen bonds only. C. covalent bonds only. D. both ionic and hydrogen bonds. E. both ionic and covalent bonds.

B

If the pH of a solution is decreased from 7 to 6, it means that the A. concentration of H+ has decreased to 1 / 10 of what it was at pH 7. B. concentration of H+ has increased to 10 times what it was at pH 7. C. concentration of OH- has increased to 10 times what it was at pH 7. D. concentration of OH- has increased by 1/7 of what it was. E. solution has become more basic.

B

It is correct to say that the action of buffers A. is of relatively little significance in living systems. B. tends to prevent great fluctuations in pH. C. depends on the formation of a great number of hydrogen ions. D. depends on the presence of many electron donors. E. is to remove hydroxyl ions from organic acids.

B

What would be the pH of a solution with a hydroxyl ion concentration (OH-) of 10-10 M? A. 2 B. 4 C. 8 D. 10 E. 14

B

Which of the following is an example of a hydrogen bond? A. the bond between C and H in methane B. the bond between the H of one water molecule and the O of another water molecule C. the bond between Na and Cl in salt D. the bond between two hydrogen atoms E. the bond between Na and Cl in saline.

B

Which of the following statements is TRUE about buffer solutions? They A. will always have a pH of 7. B. tend to maintain a relatively constant pH. C. maintain a constant pH when bases are added to them but not when acids are added to them. D. cause a lowering of pH when acids are added to them. E. are rarely found in living systems.

B

a measure of the average kinetic energy of the molecules in a body of matter A. calorie B. temperature C. heat of vaporization D. buffer E. mole

B

A given solution is found to contain 0.0001 mole of hydrogen ions (H+) per liter. Which of the following best describes this solution? A. acidic: H+ acceptor B. basic: H+ acceptor C. acidic: H+ donor D. basic: H+ donor E. neutral

C

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

C

How do strong acids, like hydrochloric acid, differ from weak acids, like carbonic acid? A. Weak acids do not release hydrogen ions when they dissociate. B. Strong acids reversibly release and reaccept hydrogen. C. They differ in the extent to which they dissociate. D. Strong acid dissociation results in the release of two or more hydrogen ions, while weak acids release only a single hydrogen ion. E. Weak acids contain carbon.

C

Temperature usually increases when water vapor condenses to liquid. Which behavior of water is most directly responsible for this phenomenon? A. change in density when it condenses to form a liquid or solid B. reactions with other atmospheric compounds C. release of heat by formation of hydrogen bonds D. release of heat by breaking of hydrogen bonds E. high surface tension

C

Which of the following liquids does NOT have a measurable pH? A. milk B. seawater C. gasoline D. orange juice E. distilled water

C

3. Most of water's unique properties result from the fact that water molecules A. are very small. B. tend to repel each other. C. are extremely large. D. tend to stick together. E. are in constant motion.

D

48. What is the maximum number of hydrogen bonds a water molecule can form with neighboring water molecules? A. one B. two C. three D. four E. five

D

A mole of ethyl alcohol weighs 46 grams. How many grams of ethyl alcohol must be added to a liter of water to produce a 2.0 millimolar (mM) solution? A. 92 B. 9.2 C. 0.92 D. 0.092 E. 0.0092

D

Desert rabbits are adapted to the warm climate because their large ears aid in the removal of heat by all of the following EXCEPT A. liquid water becoming gas. B. the high heat of vaporization of water. C. the hydrogen bonds found in water. D. kinetic energy in water decreasing.

D

Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be A. a solution. B. a solvent. C. a solute. D. an aqueous solution. E. heterogeneous.

D

The amount of energy necessary to raise the temperature of 1 gram of liquid water by 1 degree Celsius: A. depends on the initial temperature of the water sample. B. is one kilocalorie. C. 1,000 calories. D. is one calorie. E. is one Calorie

D

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called? A. a covalent bond B. a hydrogen bond C. anionic bond D. a hydration shell E. a hydrophobic bond

D

Water is able to form hydrogen bonds because A. the water molecule is polar. B. the oxygen atom in a water molecule is weakly negative. C. the hydrogen atoms in a water molecule are weakly positive. D. All of the above are correct

D

What bonds must be broken for water to go from a liquid to a gas? A. covalent B. polar covalent C. ionic D. hydrogen E. hydrophobic

D

What determines the cohesiveness of water molecules? A. hydrophobic interactions B. high specific heat C. covalent bonds D. hydrogen bonds E. ionic bonds-

D

When water is vaporized, what occurs? It is A. oxidized. B. reduced. C. decreased in the number of H+ D. destabilized and hydrogen bonds are broken. E. disrupted and its density decreases

D

Which bonds must be broken for water to vaporize? A. ionic bonds B. nonpolar covalent bonds C. polar covalent bonds D. hydrogen bonds E. Both C and D are correct.

D

Why does ice float in liquid water? A. The liquid water molecules have more energy and can push the ice up. B. The hydrogen bonds between the molecules in ice prevent the ice from sinking. C. Ice always has air bubbles that keep it afloat. D. Hydrogen bonds keep the molecules of ice farther apart than in liquid water. E. The crystalline lattice of ice causes it to be denser than liquid water.

D

a -weak acid or base that combines reversibly with hydrogen ion A. calorie B. temperature C. heat of vaporization D. buffer E. mole

D

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. half as much. C. twice as much D. three times as much E. ten times as much

E

A solution with a pH of 3 has how many more H+ than a solution with a pH of 6? A. 2 times more B. 10 times more C. 100 times more D. 200 times more E. 1000 times more

E

Assuming a temperature of 25oC, what does a pH of 7 indicate? A. The solution is neutral. B. The concentration of H+ ions is 10-7 moles per liter. C. There are H+ ions in the solution. D. Both A and B are correct. E. A, B, and C are correct.

E

Cells are surrounded by water, and cells themselves are about 70% to 95% water. As a result A. the temperature of living things tends to change relatively slowly. B. a variety of nutrient molecules are readily available as dissolved solutes C. waste products produced by cell metabolism can be easily removed D. dissolved substances can be easily transported within the cell, or between cells in multicellular organisms. E. all of the above

E

How many molecules of glycerol C3H803 would be present in 1 liter of a 1 M glycerol solution? A. 1 B. 14 C. 92 D. 1 x 10-7 E. 6.02 x 1023

E

Ice floats because A. it is colder than liquid water. B. its molecules are moving faster than in liquid water. C. it is denser than liquid water. D. its hydrogen molecules bond to the water surface film. E. its water molecules are farther apart than in liquid water.

E

Life on Earth is dependent on all the properties of water as well as the abundance of water. Which property of water is probably MOST important for the functioning of organisms at the molecular level? A. cohesion and high surface tension B. high specific heat C. high heat of vaporization D. expansion upon freezing E. versatility as a solvent

E

Sucrose has a molecular weight of 342 daltons. To make a two-molar solution of sucrose dissolve A. 342 grams of sucrose in 1 liter of water. B. 681 grams of sucrose in 2 liters of water. C. 681 grams of sucrose in 0.5 liters of water. D. 342 grams of sucrose in 2 liters of water. E. 342 grams of sucrose in 0.5 liters of water.

E

The molecular mass of glucose is 180g. To make a one-molar solution of glucose, you should do which of the following? A. Dissolve 100 g of glucose in a liter of water. B. Dissolve 180 g of glucose in a gallon of water. C. Dissolve 180 g of glucose in 100 grams of water. D. Dissolve 180 mg (milligrams) of glucose in one liter of water. E. Dissolve 180 g of glucose in water, and then add more water until the total volume of the solution is one liter.

E

Water is an excellent solvent because A. it forms spheres of hydration around charged substances B. it is polar and can hydrogen bond with polar and charged molecules. C. it is cohesive and adhesive D. It is liquid at room temperature E. All of the above.

E

Water is transported in plant tissues against gravity due to which of the following properties? A. cohesion B. adhesion C. hydrogen bonding D. surface tension E. All of the above

E

Which of the following solutions has the greater concentration of hydroxyl ions (OH-)? A. gastric juice at pH 2 B. vinegar at pH 3 C. tomatoes at pH 4 D. black coffee at pH 5 E. seawater at pH 8

E

Which of the following statements about water is CORRECT? A. Water is more dense as a solid than it is as a liquid. B. Water is more dense at 100oC than it is at 37oC. C. Water is a good solvent for lipids. D. Compared to most other substances, the temperature of water rises sharply when it absorb heat. E. Compared to most liquids, the evaporation of water requires a large amount of heat.

E

the number of grams of a substance that equals its molecular mass in Daltons A.calorie B. temperature C. heat of vaporization D. buffer E. mole

E