Question 1

Which of the following statements is true about buffer solutions?

Accepted Answer

A)   They maintain a constant pH of 7.
B)   They maintain a constant pH when acids are added to them but not when bases are added to them.
C)   They fluctuate in pH when either acids or bases are added to them.
D)   They maintain a relatively constant pH when either acids or bases are added to them.

Question 2

As the [H₃O⁺] of the solution decreases, the [OH⁻] ________.

Accepted Answer

A)   increases and thus pH increases
B)   increases and thus pH decreases
C)   decreases and thus the pH decreases
D)   decreases and thus the pH increases

Question 3

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.)

Accepted Answer

A)   50°C
B)   5°C
C)   100°C
D)   10°C

Question 4

Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________.

Accepted Answer

A)   increase in phytoplankton population
B)   drying up of lakes and streams
C)   constant breaking and reforming of hydrogen bonds in water
D)   increase in CO₂ and other greenhouse gases in the atmosphere

Question 5

Which of the following is considered to be a strong base (alkali) ?

Accepted Answer

A)   HCl → H⁺ + Cl⁻
B)   NH₃ + H⁺ ⇔ NH₄⁺
C)   H₂CO₃ ⇔ HCO₃- + H⁺
D)   NaOH → Na⁺ + OH⁻

Question 6

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Accepted Answer

A)   mass.
B)   volume.
C)   number of atoms.
D)   number of molecules.

Question 7

Use the following figure to answer the question.

Two moles of the compound in the figure would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.)

Accepted Answer

A)   30
B)   60
C)   90
D)   120

Question 8

Water has many exceptional and useful properties. Which is the rarest property among compounds?

Accepted Answer

A)   Water is a solvent.
B)   Solid water is less dense than liquid water.
C)   Water has a high heat capacity.
D)   Water has surface tension.

Question 9

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

Accepted Answer

A)   It is a strong acid that dissociates completely in water.
B)   It is a strong base that dissociates completely in water.
C)   It is a weak acid.
D)   It is a weak base.

Question 10

A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________.

Accepted Answer

A)   1000 calories, or the amount of heat required to raise the temperature of 1 g of water by 1°C
B)   10,000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°F
C)   1000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C
D)   1000 calories, or the amount of heat required to raise the temperature of 100 g of water by 100°C

Question 11

One mole (mol) of glucose (molecular mass = 180 daltons) is ________.

Accepted Answer

A)   180 × 10²³ molecules of glucose
B)   1 kilogram of glucose dissolved in 1 liter of solution
C)   180 mL of dissolved glucose
D)   180 grams of glucose

Question 12

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S will ________.

Accepted Answer

A)   have greater cohesion to other molecules of H₂S
B)   have a greater tendency to form hydrogen bonds with each other
C)   have a higher capacity to absorb heat for the same change in temperature
D)   not form hydrogen bonds with each other

Question 13

Liquid water ________.

Accepted Answer

A)   is less dense than ice
B)   has a specific heat lower than that of most other substances
C)   has a heat of vaporization higher than that of most other substances
D)   is nonpolar

Question 14

Consider the following reaction at equilibrium: CO₂ + H₂O  ⇌ \rightleftharpoons ⇌  H₂CO₃. What would be the effect of adding additional H₂O?

Accepted Answer

A)   It would drive the equilibrium dynamics to the right.
B)   It would drive the equilibrium dynamics to the left.
C)   Nothing would happen because the reactants and products are in equilibrium.
D)   Reactions in both the directions will slow down.

Question 15

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?

Accepted Answer

A)   1 × 10⁻⁹ mol of hydroxide ions per liter of lake water
B)   1 × 10⁻⁵ mol of hydroxide ions per liter of lake water
C)   5.0 M hydroxide ion
D)   5.0 × 10⁻⁵ mol of hydroxide ions per liter of lake water

Question 16

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

Accepted Answer

A)   4.0 M
B)   10⁻¹⁰ M
C)   10⁻⁴ M
D)   10⁴ M

Question 17

One of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃) . Carbonic acid is a weak acid that, when placed in an aqueous solution, dissociates into a bicarbonate ion (HCO₃⁻) and a hydrogen ion (H⁺) . (See figure.) 
 H2CO3 Carbonic acid ⇌HCO3− Bicarbonate ion +H+ Hydrogen ion \underset{	ext { Carbonic acid }}{\mathrm{H}_{2} \mathrm{CO}_{3}} ightleftharpoons \underset{	ext { Bicarbonate ion }}{\mathrm{HCO}_{3}^{-}}+\underset{	ext { Hydrogen ion }}{\mathrm{H}^{+}} Carbonic acid H2​CO3​​⇌ Bicarbonate ion HCO3−​​+ Hydrogen ion H+​

If the pH of blood drops, one would expect ________.

Accepted Answer

A)   a decrease in the concentration of H₂CO₃ and an increase in the concentration of HCO₃⁻
B)   the concentration of bicarbonate ions (HCO₃⁻)  to increase
C)   the HCO₃⁻ to act as a base and remove excess H⁺ by the formation of H₂CO₃
D)   the HCO₃⁻ to act as an acid and remove excess H⁺ by the formation of H₂CO₃

Question 18

Why does ice float in liquid water?

Accepted Answer

A)   The high surface tension of liquid water keeps the ice on top.
B)   The ionic bonds between the molecules in ice prevent the ice from sinking.
C)   Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.
D)   The crystalline lattice of ice causes it to be denser than liquid water.

Question 19

Increased atmospheric CO₂ concentrations might have what effect on seawater?

Accepted Answer

A)   Seawater will become more alkaline, and carbonate concentrations will decrease.
B)   There will be no change in the pH of seawater, because carbonate will turn to bicarbonate.
C)   Seawater will become more acidic, and carbonate concentrations will decrease.
D)   Seawater will become more acidic, and carbonate concentrations will increase.

Question 20

Thermal energy of the water in a bathtub is ________ than in a freshly brewed coffee pot because of its ________.

Accepted Answer

A)   higher; greater volume
B)   higher; high kinetic energy
C)   lower; low temperature
D)   lower; low density

Exam 3: Water and Life

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S will ________.

Correct Answer
verified

One mole (mol) of glucose (molecular mass = 180 daltons) is ________.

Correct Answer
verified

Why does ice float in liquid water?

Correct Answer
verified

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

Correct Answer
verified

Liquid water ________.

Correct Answer
verified

Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________.

Correct Answer
verified

As the [H₃O⁺] of the solution decreases, the [OH⁻] ________.

Correct Answer
verified

Water has many exceptional and useful properties. Which is the rarest property among compounds?

Correct Answer
verified

Correct Answer
verified

Increased atmospheric CO₂ concentrations might have what effect on seawater?

Correct Answer
verified

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

Correct Answer
verified

Consider the following reaction at equilibrium: CO₂ + H₂O $\rightleftharpoons$ H₂CO₃. What would be the effect of adding additional H₂O?

Correct Answer
verified

Which of the following statements is true about buffer solutions?

Correct Answer
verified

Thermal energy of the water in a bathtub is than in a freshly brewed coffee pot because of its .

Correct Answer
verified

Which of the following is considered to be a strong base (alkali) ?

Correct Answer
verified

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.)

Correct Answer
verified

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?

Correct Answer
verified

A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________.

Correct Answer
verified

Use the following figure to answer the question. Two moles of the compound in the figure would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.)

Correct Answer
verified

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Correct Answer
verified

Exam 3: Water and Life

Sulfur is in the same column of the periodic table as oxygen, but has electronegativity similar to carbon. Compared to water molecules, molecules of H₂S will ________.

Correct AnswerverifiedShow Answer

One mole (mol) of glucose (molecular mass = 180 daltons) is ________.

Correct AnswerverifiedShow Answer

Why does ice float in liquid water?

Correct AnswerverifiedShow Answer

A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance?

Correct AnswerverifiedShow Answer

Liquid water ________.

Correct AnswerverifiedShow Answer

Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________.

Correct AnswerverifiedShow Answer

As the [H₃O⁺] of the solution decreases, the [OH⁻] ________.

Correct AnswerverifiedShow Answer

Water has many exceptional and useful properties. Which is the rarest property among compounds?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Increased atmospheric CO₂ concentrations might have what effect on seawater?

Correct AnswerverifiedShow Answer

Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?

Correct AnswerverifiedShow Answer

Consider the following reaction at equilibrium: CO₂ + H₂O ⇌ \rightleftharpoons ⇌ H₂CO₃. What would be the effect of adding additional H₂O?

Correct AnswerverifiedShow Answer

Which of the following statements is true about buffer solutions?

Correct AnswerverifiedShow Answer

Thermal energy of the water in a bathtub is ________ than in a freshly brewed coffee pot because of its ________.

Correct AnswerverifiedShow Answer

Which of the following is considered to be a strong base (alkali) ?

Correct AnswerverifiedShow Answer

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.)

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________.

Correct AnswerverifiedShow Answer

Use the following figure to answer the question. Two moles of the compound in the figure would weigh how many grams? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.)

Correct AnswerverifiedShow Answer

We can be sure that a mole of table sugar and a mole of vitamin C are equal in their

Correct AnswerverifiedShow Answer

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Consider the following reaction at equilibrium: CO₂ + H₂O $\rightleftharpoons$ H₂CO₃. What would be the effect of adding additional H₂O?

Correct Answer
verified

Correct Answer
verified

Thermal energy of the water in a bathtub is than in a freshly brewed coffee pot because of its .

Correct Answer
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