chapter 4
Which of the following statements about pH is true?
The pH scale measures the concentration of hydrogen ions in a solution.
T OR F:The most precise way to calculate the salinity of seawater is to evaporate a known weight of seawater and weigh the residue.
falseeee
T OR F:The salinity of seawater is a measure of the amount of sodium and chloride in a water sample.
falseeee
As carbon dioxide enters the ocean, it ____.
forms a carbonic acid
Which region of the ocean generally lacks a thermocline?
polar region
The bending of light or sound waves is referred to as ____.
refraction
The density of seawater will increase when ____.
the salinity increases
T OR F:The amount of heat transported by water vapor in the atmosphere is greater than the amount of heat transported by ocean currents.
trueeee
T OR F: The geometry of the covalent bonds shared by the hydrogen atoms and oxygen atom in a water molecule account for its polarity.
trueeeeeee
T OR F:Red light is able to penetrate seawater the deepest.
FALSEEEE
T OR F:The density of seawater is affected by both temperature and salinity.
TRUEEE
T OR F:The pycnocline can occur at the same range of depths as a halocline.
TRUEEE
T OR F:As carbon dioxide dissolves at the surface of the ocean, it combines chemically to form a weak acid called carbonic acid.
TRUEEEE
The wavelengths of light that penetrate deepest into the ocean are ____.
green and blue
A zone in which the ocean's salinity changes rapidly with increasing depth is called ____.
halocline
The property of water that accounts for the ability of liquid water to absorb large amounts of heat and change relatively little in temperature is called ____.
high heat capacity
The thin layer of lighted water near the surface of the ocean is called the ____.
photic zone
The two most abundant elements (ions) dissolved in seawater are ____.
sodium and chloride
The average salinity of the world ocean is about ____.
3.5%
Which of the following statements is true regarding sound in the ocean?
Sound is scattered as it bounces off suspended particles in the water.
T OR F:Water resists rising in temperature as heat is added, or falling in temperature when heat is removed.
TRUE
What is the speed of sound in seawater of average salinity at the surface?
about 1,500 meters per second
What is the average residence time water stays in the ocean?
about 4100 years
Oxygen enters seawater ____.
as a byproduct of photosynthesis and diffusion from the atmosphere
Residence time is the ____.
average length of time an element spends in the ocean
Water behaves like a(n) ____, which prevents broad swings of pH.
buffer
The ocean appears to be in ____ because the proportion and amounts of its dissolved salts per unit volume are nearly constant.
chemical equilibrium
The amount of dissolved oxygen that seawater can hold in solution will be greater in ____.
colder water
T OR F:Frozen water is more dense than liquid water.
falseeeee
T OR F:Heat and temperature both measure random vibrations of an atom or a molecule.
falseeeee
What type of bond enables water molecules to stick together?
hydrogen bond
At the present time, the salinity of the ocean seems to be ____.
in chemical equilibrium, where ions are added to the ocean at the same rate as they are being removed
Heat can be carried to the polar regions ____.
in ocean currents from the tropics
The deepest thermoclines can be found ____.
in the tropics
Eighty calories of heat energy must be removed per gram of pure water at 0°C to form ice. This represents water's ____.
latent heat of fusion
The hydrogen atoms in a water molecule tend to bond to ____.
oxygen atoms of another water molecule
The ocean is stratified with respect to ____.
temperature and salinity
T OR F:Cold water can dissolve more CO2 than warm water.
TRUE
The term "salinity" refers to the total quantity of ____.
dissolved inorganic solids in water
What is meant by the mixing time of the ocean?
the time necessary to mix a substance through the ocean, about 1,600 years.
The components of ocean water whose quantities are less than 1 part per million (ppm) are considered ____.
trace elements
Sound can travel for much greater distances through water than light waves can before being absorbed because ____.
Sound waves travel through water more efficiently than light waves.
When liquid water gets below 4°C, it ____.
begins to decrease in density by expanding
How much more carbon dioxide can water hold than nitrogen or oxygen at saturation?
1,000 times more
Which statement best reflects global temperatures with respect to San Francisco, California and Norfolk, Virginia, two cities that lie along the same latitude?
San Francisco is warmer in the winter and cooler in the summer.
How does water dissolve sodium chloride (NaCl)?
The polarity of water causes the sodium ion (Na+) to separate from the chloride ion (Cl-).
Which of the following contains more heat?
a room temperature swimming pool
River water contributes which ions to the ocean?
calcium and bicarbonate ions
Which property gives water an unusually high surface tension resulting in a surface "skin" capable of supporting small objects?
cohesion
The ____ of the ocean absorbs nearly all the infrared radiation that reaches the ocean surface.
first meter (3.3 feet)
Where do dense water masses form?
near polar continental shelves
Seawater is ____ even though dissolved CO2 forms into a carbonic acid when combined with water.
slightly alkaline
The tendency for a substance to resist change in temperature with the gain or loss of heat energy is called ____.
thermal inertia
Carbon dioxide combines chemically with water to form a(n) ____.
weak acid
What processes are responsible for the ocean's salinity?
weathering and outgassing
About what percentage does water expand when it freezes?
9.0%
Because CO2 dissolves readily in the ocean, it forms a carbonic acid making the average pH of the ocean slightly acidic.
FALSE
Sound intensity increases as it travels through seawater because of spreading, scattering, and absorption.
FALSE
When a hydrogen atom (the positive end) in one water molecule is attracted to the oxygen atom (the negative end) of an adjacent water molecule, a covalent bond forms.
FALSE
If the ocean's water evaporated completely leaving its salts behind, what would the dried residue look like?
It would cover the entire planet with an even layer 45 meters thick.
The hydrogen bonds of water molecules account for which of the following?
Water can cause surface tension and wetting.
