Water and Life

What are the four emergent properties of water that are important for life? cohesion, expansion upon freezing, high heat of evaporation, capillarity cohesion, moderation of temperature, expansion upon freezing, solvent properties moderation of temperature, solvent properties, high surface tension, capillarity heat of vaporization, high specific heat, high surface tension, capillarity polarity, hydrogen bonding, high specific heat, high surface tension Answer: B 2

What are the four emergent properties of water that are important for life? cohesion, expansion upon freezing, high heat of evaporation, capillarity cohesion, moderation of temperature, expansion upon freezing, solvent properties moderation of temperature, solvent properties, high surface tension, capillarity heat of vaporization, high specific heat, high surface tension, capillarity polarity, hydrogen bonding, high specific heat, high surface tension 3

Water shows high cohesion and surface tension and can absorb large amounts of heat because of large numbers of which of the following bonds between water molecules? strong ionic bonds nonpolar covalent bonds polar covalent bonds hydrogen bonds weak ionic bonds Answer: D This question emphasizes that the unique nature of water is due to extensive hydrogen bonding. 4

Water shows high cohesion and surface tension and can absorb large amounts of heat because of large numbers of which of the following bonds between water molecules? strong ionic bonds nonpolar covalent bonds polar covalent bonds hydrogen bonds weak ionic bonds 5

Water has an unusually high specific heat. What does this mean? At its boiling point, water changes from liquid to vapor. More heat is required to raise the temperature of water. Ice floats in liquid water. Salt water freezes at a lower temperature than pure water. Floating ice can insulate bodies of water. Answer: B 6

Water has an unusually high specific heat. What does this mean? At its boiling point, water changes from liquid to vapor. More heat is required to raise the temperature of water. Ice floats in liquid water. Salt water freezes at a lower temperature than pure water. Floating ice can insulate bodies of water. 7

Surfactants reduce surface tension of a liquid Surfactants reduce surface tension of a liquid. Which of the following would result if water was treated with surfactants? Surfactant-treated water droplets would form a thin film instead of beading on a waxed surface. Surfactant-treated water would form smaller droplets when dripping from a sink. Water striders would sink. All of the above would occur. Only A and C would occur. Answer: D 8

Surfactants reduce surface tension of a liquid Surfactants reduce surface tension of a liquid. Which of the following would result if water was treated with surfactants? Surfactant-treated water droplets would form a thin film instead of beading on a waxed surface. Surfactant-treated water would form smaller droplets when dripping from a sink. Water striders would sink. All of the above would occur. Only A and C would occur. 9

In a glass of old-fashioned lemonade, which is the solvent? lemon juice sugar water lemonade mixture ice Answer: C

In a glass of old-fashioned lemonade, which is the solvent? lemon juice sugar water lemonade mixture ice

Which of the following would most likely form a colloid? small hydrophobic molecule small hydrophilic molecule large hydrophobic molecule large hydrophilic molecule A and C Answer: D

Which of the following would most likely form a colloid? small hydrophobic molecule small hydrophilic molecule large hydrophobic molecule large hydrophilic molecule A and C

Skin is coated with a hydrophobic glycolipid Skin is coated with a hydrophobic glycolipid. What would happen if this was not present? Water would be lost from skin cells more quickly. Skin would swell when swimming. Skin would wrinkle more. A and B only A, B, and C Answer: D

Skin is coated with a hydrophobic glycolipid Skin is coated with a hydrophobic glycolipid. What would happen if this was not present? Water would be lost from skin cells more quickly. Skin would swell when swimming. Skin would wrinkle more. A and B only A, B, and C

What is the concentration of OH ions in a solution where pH  10? 1  10-10 M 1  1010 M 1  104 M 1  10-4 M 1  10-7 M Answer: D

What is the concentration of OH ions in a solution where pH  10? 1  10-10 M 1  1010 M 1  104 M 1  10-4 M 1  10-7 M

Compared to an acidic solution at pH 5, a basic solution at pH 8 has 1,000 times more hydrogen ions. 1,000 times less hydrogen ions. 100 times less hydrogen ions. the same number of hydrogen ions but more hydroxide ions. 100 times less hydroxide ions. Answer: B

Compared to an acidic solution at pH 5, a basic solution at pH 8 has 1.000 times more hydrogen ions. 1.000 times less hydrogen ions. 100 times less hydrogen ions. the same number of hydrogen ions but more hydroxide ions. 100 times less hydroxide ions.

Which of the following acts as a pH buffer in blood? carbonic acid bicarbonate ion carbonate ion hydroxide ion A and B Answer: E

Which of the following acts as a pH buffer in blood? carbonic acid bicarbonate ion carbonate ion hydroxide ion A and B

Scientific Skills Questions

Scientists predict that acidification of the ocean will lower the concentration of dissolved carbonate ions (CO32), which are required for coral reef calcification. To test this hypothesis, what would be the independent variable? ocean pH the rate of calcification the amount of atmospheric CO2 time volume of seawater Answer: A

Scientists predict that acidification of the ocean will lower the concentration of dissolved carbonate ions (CO32), which are required for coral reef calcification. To test this hypothesis, what would be the independent variable? ocean pH the rate of calcification the amount of atmospheric CO2 time volume of seawater

Based on this graph, what is the relationship between carbonate ion concentration and calcification rate? As the acidity of the seawater increased, the rate of calcification decreased. As the rate of calcification increased, the concentration of carbonate ions increased. As the concentration of carbonate ions increased, the rate of calcification decreased. As the concentration of carbonate ions increased, the rate of calcification increased. Answer: D

Based on this graph, what is the relationship between carbonate ion concentration and calcification rate? As the acidity of the seawater increased, the rate of calcification decreased. As the rate of calcification increased, the concentration of carbonate ions increased. As the concentration of carbonate ions increased, the rate of calcification decreased. As the concentration of carbonate ions increased, the rate of calcification increased.

If the seawater carbonate ion concentration is 250 µmol/kg, what is the approximate rate of calcification according to this graph? 5 mmol CaCO3 per m2 per day 10 mmol CaCO3 per m2 per day 15 mmol CaCO3 per m2 per day 20 mmol CaCO3 per m2 per day Answer: B

If the seawater carbonate ion concentration is 250 µmol/kg, what is the approximate rate of calcification according to this graph? 5 mmol CaCO3 per m2 per day 10 mmol CaCO3 per m2 per day 15 mmol CaCO3 per m2 per day 20 mmol CaCO3 per m2 per day

This figure suggests that increased atmospheric concentrations of CO2 will slow the growth of coral reefs. Do the results of the previous experiment support that hypothesis? No; more atmospheric CO2 causes a decrease in the amount of CO32   in seawater, leading to faster reef growth. Yes; more CO2  causes an increase  in the amount of CO32 in seawater, leading to slower reef growth. No; more atmospheric CO2  causes an increase in the amount of CO32   in seawater, leading to faster reef growth. Yes; more CO2  causes a decrease  in the amount of CO32  in seawater, leading to slower reef growth. Answer: D

This figure suggests that increased atmospheric concentrations of CO2 will slow the growth of coral reefs. Do the results of the previous experiment support that hypothesis? No; more atmospheric CO2 causes a decrease in the amount of CO32   in seawater, leading to faster reef growth. Yes; more CO2  causes an increase  in the amount of CO32 in seawater, leading to slower reef growth. No; more atmospheric CO2  causes an increase in the amount of CO32   in seawater, leading to faster reef growth. Yes; more CO2  causes a decrease  in the amount of CO32  in seawater, leading to slower reef growth.