OCE 1001 Exam 2

Which of the following is not one of the reasons why water is considered a universal solvent?

When the ions separate, they become attracted to identically charged water molecules.

Which of the following processes increase seawater salinity? Choose all that apply.

evaporation sea ice formation

Which of the following processes causes sea surface salinity to increase near the Tropics of Cancer and Capricorn?

evaporation

Which property of water causes coastal communities to have only moderate differences in daily highs and lows when compared to inland communities?

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 processes can provide fresh drinking water from seawater? Choose all that apply.

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

As shown in the video demonstration, air has _____ electrical conductivity and a metal key has _____ electrical conductivity.

low; high

A group of two or more atoms held together by mutually shared electrons are called ________.

molecules

As demonstrated by the fluids shown in the video, the higher the salinity of a fluid, the __________ the light lit up.

more

Subatomic particles with a neutral charge are called ________.

neutrons

On an annual basis which of the following fluxes between reservoirs of the hydrologic cycle is the largest?

ocean to atmosphere

What are the two controlling factors that affect water density?

temperature and salinity

What is allowing electrical current to pass through tap water from one electrode to the other?

the amount of salt (dissolved substances)

In which fluid did the bulb shine the brightest?

the beaker filled with seawater

Of the three different colored waters separated by slats, which one has the highest density?

the cold (blue) water, which has the lowest temperature

Can you determine where each sample was from? Use what you know about relative salinity and its global variation. Label the samples accordingly and complete the two sentences with labels that correctly describe seasonal sea ice melt and seawater freezing and the relationship to salinity. Samples were collected at the locations of the circles on the map.

-Locations that experience seasonal seawater freezing have increased salinity in the surrounding seawater during that time. - Locations that experience seasonal ice melting have decreased salinity in the surrounding seawater during that time. Sample A- Just east of the Bahamas Sample B- off the west coast of Africa near the equator Sample C- from the Red Sea Sample D- from the Baltic Sea

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

1000

The average salinity of typical seawater is:

3.5%

Imagine you are swimming in the open ocean at a location near the equator. Based on the following data, can you determine how deep you would need to dive to reach a water temperature of 19°C?

550 meters

Which of the following best describes the Electrolysis Method for desalination?

A current is run through positive and negative electrodes in freshwater separated by semipermeable membranes from seawater.

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)

The image below depicts several water molecules. Match the correct letter to each of the following features.

A: Hydrogen bond C: Hydrogen atom E: Negatively charged side of the water molecule D: Positively charged side of the water molecule B: Oxygen atom

Match the correct letter to each of the states of water listed below.

A: Liquid C: Gas B: Solid

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

B

Which of the following statements is/are true regarding acidic and alkaline substances? Choose all that apply.

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. pH stands for "power of hydrogen."

The image below depicts water in the three states of matter. Match the processes involved as water changes state with the correct letter.

C: Condensation B: Melting D: Freezing A: Vaporization (evaporation/boiling)

There is a general trend of decreasing pH with increasing water depth in the ocean. What is the cause of this pattern?

Deeper, colder ocean water contains more dissolved carbon dioxide, which causes the pH to be lower.

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

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

Which process in the hydrologic cycle is most effective at increasing ocean salinity on a global scale?

Evaporation

Which statement accurately describes the thermostatic effect of water on climate moderation?

Evaporation in the tropics has a cooling effect on ocean temperature.

Of the following statements about the density of freshwater and the formation of ice, which is/are true? Choose all that apply.

Ice is less dense than liquid water, which is why ice floats. As the temperature of water decreases from 4°C to 0°C, its density decreases. Water's maximum density is at 4°C. Water at 2°C is less dense than it is at 4°C.

How do hydrogen bonds define the three states of matter in water? Choose all that apply.

In liquid water, there are some hydrogen bonds between water molecules that form and break repeatedly. 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. Ice has more hydrogen bonds than water vapor does.

Which of the following statements regarding water density is correct?

Increasing the pressure decreases the temperature of maximum density for freshwater because the formation of bulky ice crystals is inhibited.

What happened when a new (green) water mass was introduced into the system?

It came to equilibrium in the middle of the tank.

What makes water a polar molecule?

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

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 best describes the Distillation Method for desalination?

Saltwater is boiled and the water vapor is passed through a cooling condenser, where it condenses as freshwater.

Which of the following best describes the Freeze Separation Method for desalination?

Seawater is frozen and thawed multiple times, with the salts washed from the ice between each thawing.

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.

Of the following statements about seawater salinity, which is/are true? Choose all that apply.

Seawater salinity averages 3.5%. The two most common dissolved components in seawater are sodium and chloride. Seawater salinity averages 35 ppt.

Which of the following best defines heat capacity?

The amount of heat energy required to raise the temperature of a substance by 1 degree Celsius.

What happened when the two slats were pulled out?

The blue water sank to the bottom and the red water rose to the top.

Of the following statements about the pH of seawater, which is/are true? Choose all that apply.

The carbonate buffering system stabilizes the pH of seawater. The pH of seawater is higher than that of pure water. Dissolving carbon dioxide in seawater decreases the pH of seawater.

Which of the following best defines temperature?

The direct measure of the average kinetic energy of a substance's molecules.

Why do ionic compounds dissolve readily in water?

The electrostatic attraction between ions is weakened by the polarity of water.

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.

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.

Of the following statements about seawater properties in high and low latitudes, which is/are true? Choose all that apply.

There is a thermocline in low latitudes. There is a halocline in low latitudes. There is a halocline in high latitudes. There is a pycnocline in low latitudes.

Of the following properties of water, which is/are caused by the unusual geometry of water molecules? Choose all that apply.

Water has the ability to dissolve just about anything. Water molecules have polarity. Water molecules form hydrogen bonds. Water has cohesion and surface tension.

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.

Which of the following best describes the Reverse Osmosis Method for desalination?

Water on the salty side of a semipermeable membrane is pushed under high pressure through the membrane to the freshwater side.

Which of the following statements is/are true of sea ice? Choose all that apply.

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

The principal reason that oil and water do not mix, even when shaken, is that oil molecules __________.

are nonpolar whereas water molecules are polar

The basic building blocks of all matter are called ________.

atoms

The states of matter in which water exists is primarily determined by:

temperature

On an annual basis which of the following fluxes between reservoirs of the hydrologic cycle is the smallest?

continent to ocean

The density curve for high latitudes shows ________ density at the surface and ________ density at depth.

decreased; increased

Precipitation ... Sea ice formation ... High temperature ... Evaporation ... River input ...

decreases seawater salinity. increases seawater salinity. does not change seawater salinity. increases seawater salinity. decreases seawater salinity.

As the salinity of seawater increases, its:

density increases

Subatomic particles with a negative charge are called ________.

electrons

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

The salinity curve for low latitudes shows ________ salinity at the surface and ________ salinity at depth.

increased; decreased

Human consumption of which of the following components of seawater helps prevent goiter?

iodine

Atoms that have lost or gained one or more electrons are called ________.

ions

The surface tension of water:

is relatively high.

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

lemon juice

What common household item is used in this video to demonstrate a technique used by oceanographers to measure seawater salinity?

light bulb

The accompanying image depicts the three states of water and the processes by which water changes from one state to another. Use this information to match the correct state to each of the following statements. Note that in this context, "water" refers to water in liquid form.

liquid gas gas gas solid solid

Subatomic particles with a positive charge are called ________.

protons

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

pure water

A layer of rapidly changing density with depth is called a ________.

pycnocline

Which of the following processes decrease seawater salinity?

sea ice melting river runoff precipitation

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

sodium hydroxide

What common household item is used in this video to demonstrate how the ocean is layered based on density?

tap water, with a small amount of food coloring

Hydrogen bonds form between neighboring water molecules because of:

the polarity of water molecules.

A layer of rapidly changing temperature with depth is called a ________.

thermocline