front 1 In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by | back 1 polar covalent bonds |
front 2 The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called? | back 2 a hydrogen bond |
front 3 An example of a hydrogen bond is the bond between | back 3 the H of one water molecule and the O of another water molecule |
front 4 Water is able to form hydrogen bonds because | back 4 the bonds that hold together the atoms in a water molecule are polar covalent bonds |
front 5 What gives rise to the cohesiveness of water molecules? | back 5 hydrogen bonds |
front 6 Which of the following effects is produced by the high surface tension of water? | back 6 a water strider can walk across the surface of a small pond |
front 7 Which of the following takes place as an ice cube cools a drink? | back 7 Kinetic energy in the drink decreases |
front 8 Which of the following statements correctly defines a kilocalorie? | back 8 the amount of heat required to raise the temperature of 1kg of water by 1°C |
front 9 The nutritional information on a cereal box shows that one serving of a dry cereal has 200 kilocalories. If one were to burn one serving of the cereal, the amount of heat given off would be sufficient to raise the temperature of 20kg of water how many degrees Celsius? | back 9 10.0°C |
front 10 Water's high specific heat is mainly a consequence of the | back 10 absorption and release of heat when hydrogen bonds break and form |
front 11 Which type of bond must be broken for water to vaporize? | back 11 hydrogen bonds |
front 12 Temperature usually increases when water condenses. Which behavior of water is most directly responsible for this phenomenon? | back 12 the release of heat by the formation of hydrogen bonds |
front 13 At what temperature is water at its densest? | back 13 4°C |
front 14 Why does ice float in liquid water? | back 14 Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water |
front 15 The following question is based on the figure of a solute molecule surrounded by a hydration shell of water. Based on your knowledge of the polarity of water molecules, the solute molecule is most likely | back 15 positively charged |
front 16 Hydrophobic substances such as vegetable oil are | back 16 nonpolar substances that repel water molecules |
front 17 One mole (mol) of a substance is | back 17 6.02E23 molecules of the substance and the molecular mass of the substance expressed in grams |
front 18 How many molecules of glucose (C6H2O6 molecular mass = 180 daltons) would be present in one mole of glucose? | back 18 6.02E23 |
front 19 How many molecules of glycerol (C3H8O3) would be present in 1L of a 1M glycerol solution? | back 19 6.02E23 |
front 20 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 particles (molecules or ions)? | back 20 1 L of 1.0M NaCl |
front 21 The molecular mass of glucose (C6H12O6) is 180g. Which of the following procedures should you carry out to make a 1M solution of glucose? | back 21 Dissolve 180g of glucose in water, and then add more water until the total volume of the solution is 1 L |
front 22 The molecular mass of glucose (C6H12O6) is 180g. Which of the following procedures should you carry out to make a 0.5M solution of glucose? | back 22 Dissolve 90g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L |
front 23 How many grams of the molecule CH3COOH (C=12, O=16, H=1) would be equal to 1 mol of the molecule? | back 23 60 |
front 24 How many grams of the molecule CH3COOH would be required to make 1L of a 0.5M solution of the molecule? (C=12, O=16, H=1) | back 24 30 |
front 25 How many grams of the molecule CH3COOH would be required to make 2.5L of a 1M solution of the molecule? (C=12, O=16, H=1) | back 25 150 |
front 26 A small birthday candle is weighed, then lighted and placed beneath a metal can containing 100mL of water. Careful records are kept as the temperature of the water rises. Data from this experiment are shown on the graph. What amount of heat energy is released in the burning of candle wax? | back 26 0.5 kilocalories per gram of wax burned |
front 27 Identical heat lamps are arranged to shine on identical containers of water and methanol (wood alcohol), so that each liquid absorbs the same amount of energy minute by minute. The covalent bonds of methanol molecules are non-polar, 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 27 graph |
front 28 You have a freshly-prepared 0.1M solution of glucose in water. Each liter of this solution contains how many glucose molecules? | back 28 6.02E24 |
front 29 The molecular weight of water is 18 daltons. What is the molarity of 1 liter of pure water? | back 29 55.6M |
front 30 You have a freshly-prepared 1M solution of glucose in water. You carefully pour out a 100mL sample of that solution. How many glucose molecules are included in that 100mL sample? | back 30 6.02E24 |
front 31 Which of the following ionizes completely in solution and is considered to be a strong acid? | back 31 HCl |
front 32 Which of the following ionizes completely in solution and is considered to be a strong base (alkali)? | back 32 NaOH |
front 33 Which of the following statements is completely correct? | back 33 NH₃ is a weak base (alkali) and H₂CO₃ is a strong acid |
front 34 A given solution contains 0.0001 (10⁻⁴) moles of hydrogen ions [H+] per liter. Which of the following best describes this solution? | back 34 acidic: H⁺ donor |
front 35 A solution contains 0.0000001(10⁻⁷) moles of hydroxyl ions [OH⁻] per liter. Which of the following best describes this solution? | back 35 neutral |
front 36 What is the pH of a solution with a hydroxyl ion [OH⁻] concentration of 10⁻¹² M? | back 36 pH 2 |
front 37 What is the pH of a solution with a hydrogen ion [H⁺] concentration of 10⁻⁸ M? | back 37 pH 8 |
front 38 Which of the following solutions has the greatest concentration of hydrogen ions [H⁺]? | back 38 gastric juice at pH 2 |
front 39 Which of the following solutions has the greatest concentration of hydroxyl ions [OH⁻]? | back 39 seawater at pH 8 |
front 40 If the pH of a solution is decreased from 9 to 8, it means that the | back 40 concentration of H⁺ has increased 10-fold (10X) compared to what it was at pH9 and concentration of OH⁻ has decreased to one-tenth (1/10) what it was at pH 9 |
front 41 If the pH of a solution is increased from pH 5 to pH 7, it means that the | back 41 concentration of OH⁻ is 100 times greater than what it was at pH 5 |
front 42 One liter of a solution of pH 2 has how many more hydrogen ions (H⁺) than 1L of a solution of pH 6? | back 42 10,000 times more |
front 43 One liter of a solution pH 9 has how many more hydroxyl ions (OH⁻) than 1L of a solution of pH 4? | back 43 100,000 times more |
front 44 Which of the following statements is true about buffer solutions? | back 44 they maintain a relatively constant pH when either acids or bases are added to them |
front 45 Buffers are substances that help resist shifts in pH by | back 45 Donating H⁺ to a solution when they have been depleted and accepting H⁺ when they are in excess |
front 46 one of the buffers that contribute to pH stability in human blood is carbonic acid (H₂CO₃). Carbonic acid is a weak acid that dissociates into a bicarbonate ion (HCO₃⁻) and a hydrogen ion (H⁺). Thus, H₂CO₃↔HCO₃⁻+H⁺ If the pH of the blood drops, one would expect | back 46 the HCO₃⁻ to act as a base and remove excess H⁺ with the formation of H₂CO₃ |
front 47 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+). Thus, H2CO3 ↔ HCO3- + H+ If the pH of the blood increases, one would expect | back 47 a decrease in the concentration of H2CO3 and an increase in the concentration of H2O |
front 48 Assume that acid rain has lowered the pH of a particular lake to pH 4.0. What is the hydroxyl ion concentration of this lake? | back 48 1x10⁻¹⁰ mol of hydroxyl ion per liter of lake water |
front 49 Research indicates that acid precipitation can damage living organisms by | back 49 washing away certain mineral ions that help buffer soil solution and are essential nutrients for plant growth |
front 50 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 50 none of the other answer choices correctly describes these solutions |
front 51 Pure, freshly-distilled water has a pH of 7. This means that | back 51 the concentration of H+ ions in the water equals the concentration of OH- ions in the water |
front 52 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 52 c |
front 53 Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O → H2CO3. Carbonic acid (H2CO3) is a weak acid. Respiring cells release CO2. What prediction can we make about the pH of blood as that blood first comes in contact with respiring cells? | back 53 blood pH will decrease slightly |
front 54 A 100 mL beaker contains 10 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 results of this mixing? | back 54 the pH of the beaker's contents falls |
front 55 Equal volumes of vinegar from a freshly-opened bottle are added to each of the following solutions. After complete mixing, which of the mixtures will have the highest pH? | back 55 100mL of household cleanser containing 0.5M ammonia |
front 56 You have two beakers; one contains pure water, the other contains pure methanol (wood alcohol). The covalent bonds of methanol molecules are nonpolar, so there are no hydrogen bonds among methanol molecules. You pour crystals of table salt (NaCl) into each beaker. Predict what will happen. | back 56 NaCl crystals will dissolve readily in water but will not dissolve in methanol |
front 57 You have two beakers. One contains a solution of HCl at pH = 1.0. The other contains a solution of NaOH at pH = 13. Into a third beaker, you slowly and cautiously pour 20 mL of the HCL and 20 mL of the NaOH. After complete stirring, the pH of the mixture will be | back 57 7.0 |