CHAPTER 5 OCEANOGRAPHY

At what temperature (in degrees centigrade) does saltwater freeze?

-2 degrees C

How do changes in molecular motion cause most substances, including water, to expand as they warm and contract as they cool?

-As a substance cools, the molecules move less and take up less space. -As a substance heats up, the molecules move more and take up more space.

Which of the following statements is/are true regarding hydrogen bonds in water?

-Hydrogen bonds are responsible for the high heat capacity of water -Hydrogen bonds are responsible for the high latent heat of melting of ice to liquid water. -Hydrogen bonds are responsible for the high latent heat of vaporization of liquid water to water vapor.

A block of ice is in a deep freezer at -40°C. The ice is removed from the freezer and is placed in the sink. When will the ice begin to melt?

-Ice begins to melt after 20 calories of heat per gram of water is applied. -Ice begins to melt when it reaches 0°C.

Why is ice less dense than liquid water?

-Ice crystals have a hexagonal shape. -Ice crystals are bulky. -Ice expands as it freezes.

Which of the following statements is true of water in a solid state?

-It is rigid and forms a three-dimensional crystalline shape. -Water molecules in ice remain in a relatively fixed position and are not as mobile as they are in the liquid state, where there are fewer hydrogen bonds.

Which of the following statements is/are true of sea ice?

-Sea ice formation increases the salinity of remaining seawater. -When sea ice forms, the water molecules preferentially exclude any salt in the water, resulting in ice that is mostly fresh.

How do hydrogen bonds define the three states of matter in water?

-There are no hydrogen bonds when water is in a gas phase. -Water will be a solid if there are hydrogen bonds between all water molecules. -In liquid water, there are some hydrogen bonds between water molecules that form and break repeatedly. -Ice has more hydrogen bonds than water vapor does.

Which of the following processes increase seawater salinity?

-evaporation -sea ice formation

Which of the following processes can provide fresh drinking water from seawater?

-melting of icebergs -freeze separation of sea ice -distillation of evaporated seawater

Which of the following statements is/are true regarding acidic and alkaline substances?

-pH stands for "power of hydrogen." -Blood, eggs, and seawater have a similar pH, adding support to the theory that life originally evolved in the ocean. -pH is a measure of the concentration of hydrogen ions in a solution

Which of the following processes increase(s) surface salinity?

-sea ice formation -evaporation

Which of the following processes decrease seawater salinity?

-sea ice melting -river runoff -precipitation

At what temperature (in degrees centigrade) does the density of water decrease dramatically as it cools?

0 degrees C

Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.

1. B: Oxygen atom 2. E: Negatively charged side of the water molecule 3. D: Positively charged side of the water molecule 4. C: Hydrogen atom 5. A: Hydrogen bond

Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.(3)

1. B: Solid 2. A: Liquid 3. C: Gas

Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.(2)

1. C: Condensation 2. A: Vaporization (evaporation/boiling) 3. D: Freezing 4. B: Melting

How much more acidic is a substance with a pH of 2 than a substance with a pH of 5?

1000

In the figure above, which letters on the graph represent the high latitudes and the low latitudes, respectively?

A, B

Part E: The diagram below shows selected components of the hydrologic cycle. Match the correct letter to each process (arrow) indicated.

A: Greatest amount of evaporation (worldwide) E: Smaller amount of evaporation, including transpiration (worldwide) F: Infiltration D: Runoff C: Smaller amount of precipitation (worldwide) B: Greatest amount of precipitation (worldwide)

If you want to drink a cold glass of water, why might you want to add ice?

Any heat that is absorbed by the water will go into melting the ice, not raising the temperature of the water, so the water will stay cooler longer.

In the figure above, which shows water molecules. Which label(s) indicate a covalent bond?

B

In the figure above, which letter on the graph represents the halocline?

C

In the figure above, which shows four boxes with equal volumes of liquid water molecules. Which box depicts water at the coolest temperature?

C

Part F: This diagram shows how seawater temperature varies with depth. Match the correct letter to the items indicated below.

E: Curve for high latitudes D: Curve from low latitudes B: Mixed layer C: Layer with the highest density A: Thermocline

Part D: On the lower pie diagram shown below, match the abundance of each dissolved component in seawater with its correct slice of the pie.

E: Magnesium D: Calcium C: Chloride B: Sodium F: Potassium A: Sulfate

Why is the latent heat of vaporization for water so much higher than the latent heat of melting?

For melting, only some hydrogen bonds need to be broken, whereas for vaporization, all hydrogen bonds must be broken.

What makes water a polar molecule?

It has a positive hydrogen side and a negative oxygen side.

What mechanism is primarily responsible for the observed surface salinity in the low latitudes?

Rates of evaporation are high, causing surface salinity to be high.

What mechanisms are primarily responsible for the observed surface salinity near the poles?

Rates of evaporation are low and rates of ice melt are high, causing salinity to be low.

In what way does water behave unusually as it cools?

The density of liquid water increases as it cools; then the density starts to decrease as it freezes.

Which attributes of the water molecule arise from the unique bend in its geometry?

The hydrogen end has a positive charge, and the oxygen end has a negative charge.

Which statement accurately describes the interaction between a water molecule and sodium chloride as it dissolves?

The negative oxygen end of the water molecule is attracted to the positive sodium ion.

Why are water molecules in a gas phase able to move rapidly and independently of each other?

There are no hydrogen bonds between water molecules in a gas phase, so each water molecule acts as an individual

Why does the water molecule have polarity?

Water is geometrically bent to give one side, or pole, a positive charge and the opposite side a negative charge.

Why is water able to dissolve salt?

Water molecules are polar and are attracted to the electrically charged ions that form salts.

If all the water in the ocean was evaporated and only the solid salt was left behind, how much salt would there be?

enough to form a layer about 500 feet thick that covers all of Earth

In the figure above, what property of water prevents the flame from bursting the water balloon?

high heat capacity

Which of the following processes is responsible for the high surface salinities in regions with hot climates?

high rates of evaporation

Which of the following substances releases the most hydrogen ions when dissolved in water?

lemon juice

In which of the following substances are there equal numbers of hydrogen ions and hydroxide ions?

pure water

Which of the following substances releases the most hydroxide ions when dissolved in water?

sodium hydroxide