front 1 The loss of water from a plant by transpiration cools the leaf. Movement of water in transpiration requires both adhesion to the conducting walls and wood fibers of the plant and cohesion of the molecules to each other. A scientist wanted to increase the rate of transpiration of a crop species to extend its range into warmer climates. The scientist substituted a nonpolar solution with an atomic mass similar to that of water for hydrating the plants. What do you expect the scientist's data will indicate from this experiment? | back 1 Transpiration rates will fall to zero as nonpolar compounds do not have the properties necessary for adhesion and cohesion. |
front 2 Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results? | back 2 line going down |
front 3 If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions ________. | back 3 is 10 times higher in the cytoplasm than in the mitochondrial matrix |
front 4 How would acidification of seawater affect marine organisms? Acidification of seawater would ________. | back 4 decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals |
front 5 Increased atmospheric CO2 concentrations might have what effect on seawater? | back 5 Seawater will become more acidic, and carbonate concentrations will decrease. |
front 6 A beaker contains 100 milliliters (mL) of NaOH solution at pH = 13. A technician carefully pours into the beaker 10 mL of HCl at pH = 1. Which of the following statements correctly describes the result of this mixing? | back 6 The pH of the beaker's contents will decrease. |
front 7 Which of the following graphs describes the relationship between [H3O+] and pH? | back 7 line going down |
front 8 As the [H3O+] of the solution decreases, the [OH-] ________. | back 8 increases and thus pH increases |
front 9 Consider two solutions: solution X has a pH of 4; solution Y has a pH of 7. From this information, we can reasonably conclude that ________. | back 9 the concentration of hydrogen ions in solution X is 1000 times as great as the concentration of hydrogen ions in solution Y |
front 10 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? | back 10 1 × 10-9 mol of hydroxide ions per liter of lake water |
front 11 Carbon dioxide in the atmosphere dissolves with the raindrops. The pH of raindrops is ________. | back 11 slightly acidic |
front 12 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.) | back 12 the HCO3- to act as a base and remove excess H+ by the formation of H2CO3 |
front 13 Which of the following statements is true about buffer solutions? | back 13 They maintain a relatively constant pH when either acids or bases are added to them. |
front 14 What is the hydroxyl ion (OH-) concentration of a solution of pH 8? | back 14 10-6 M |
front 15 What is the pH of a solution with a hydroxyl ion (OH-) concentration of 10-10 M? | back 15 pH 4 |
front 16 A solution contains 0.0000001 (10-7) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution? | back 16 neutral |
front 17 A 0.01 M solution of a substance has a pH of 2. What can you conclude about this substance? | back 17 It is a strong acid that dissociates completely in water. |
front 18 Which of the following is considered to be a strong base (alkali)? | back 18 NaOH → Na+ + OH- |
front 19 Consider the following reaction at equilibrium: CO2 + H2O ⇌ H2CO3. What would be the effect of adding additional H2O? | back 19 It would drive the equilibrium dynamics to the right. |
front 20 A solution with a pH of 2 has how many more protons in it than a solution with a pH of 4? | back 20 100 times more |
front 21 Rank, from low to high, the pH of blood, stomach acid, and urine. | back 21 stomach acid, urine, blood |
front 22 Identical heat lamps are arranged to shine on two identical containers, one containing water and one methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. Which of the following graphs correctly describes what will happen to the temperature of the water and the methanol? | back 22 dash line on top; splitting away from each other |
front 23 How much of 0.5 M glucose (molecular mass 180) is needed to provide 100 mg of glucose? | back 23 1.11 mL |
front 24 How many grams of the compound in the figure are required to make 1 liter of a 0.5 M solution? (Note: The atomic masses, in daltons, are approximately 12 for carbon, 1 for hydrogen, and 16 for oxygen.) | back 24 30 |
front 25 Use the following figure to answer the question. | back 25 120 |
front 26 Use the following figure to answer the question. | back 26 positively charged |
front 27 How does 0.5 M sucrose (molecular mass 342) solution compare to 0.5 M glucose (molecular mass 180) solution? | back 27 Both have 3.01 × 1023 molecules. |
front 28 You have a freshly prepared 0.1 M sucrose (molecular mass 342) solution, which means ________. | back 28 6.02 × 1022 of sucrose molecules or 34.2 g of sucrose is present in the solution |
front 29 The molar mass of glucose is 180 grams per mole (g/mol). Which of the following procedures should you carry out to make a 1 M solution of glucose? In 0.8 liter (L) of water, dissolve ________. | back 29 180 g of glucose, and then add more water until the total volume of the solution is 1 L |
front 30 When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)? | back 30 1 liter of 1.0 M NaCl |
front 31 One mole (mol) of glucose (molecular mass = 180 daltons) is ________. | back 31 180 grams of glucose |
front 32 Melting of ice and thus reduced feeding opportunities for polar bears is occurring because of the ________. | back 32 increase in CO2 and other greenhouse gases in the atmosphere |
front 33 Why is a steam burn more severe than a hot water burn? | back 33 Steam contains more energy than water. |
front 34 Hydrophobic substances such as vegetable oil are ________. | back 34 nonpolar substances that repel water molecules |
front 35 Why does ice float in liquid water? | back 35 Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water. |
front 36 A dietary Calorie equals 1 kilocalorie. One kilocalorie equals ________. | back 36 1000 calories, or the amount of heat required to raise the temperature of 1 kg of water by 1°C |
front 37 Low humidity in the atmosphere on a hot day ________. | back 37 helps in cooling because water evaporates from the skin faster |
front 38 Thermal energy of the water in a bathtub is ________ than in a freshly brewed coffee pot because of its ________. | back 38 higher; greater volume |
front 39 Which of the following effects can occur because of the high surface tension of water? | back 39 A raft spider can walk across the surface of a small pond. |
front 40 Water has many exceptional and useful properties. Which is the rarest property among compounds? | back 40 Solid water is less dense than liquid water. |
front 41 To act as an effective coolant in a car's radiator, a substance has to have the capacity to absorb a great deal of heat. You have a reference book with tables listing the physical properties of many liquids. In choosing a coolant for your car, which table would you check first? | back 41 specific heat |
front 42 The cities of Portland, Oregon, and Minneapolis, Minnesota, are at about the same latitude, but Minneapolis has much hotter summers and much colder winters than Portland. Why? | back 42 The ocean near Portland moderates the temperature. |
front 43 Which of the following can be attributed to water's high specific heat? | back 43 A lake heats up more slowly than the air around it. |
front 44 Liquid water ________. | back 44 has a heat of vaporization higher than that of most other substances |
front 45 Cohesion, surface tension, and adhesion are the properties of water molecules that ________. | back 45 are a result of hydrogen bonding |
front 46 Water molecules can form hydrogen bonds with ________. | back 46 compounds that have polar covalent bonds |
front 47 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 ________. | back 47 not form hydrogen bonds with each other |
front 48 The partial negative charge in a molecule of water occurs because ________. | back 48 the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus |
front 49 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? | back 49 a hydrogen bond |
front 50 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by ________. | back 50 polar covalent bonds |