The Properties of Water Flashcards
1
Q
This substance makes life possible on Earth
A
Water
2
Q
What is the only common substance to exist in the natural environment in all three physical states of matter?
A
Water
3
Q
This aspect of the water molecule allows it to interact with other molecules
A
Structure
4
Q
In the water molecule, electrons are shared between oxygen and hydrogen in this type of bond
A
Covalent
5
Q
What type of covalent bond is present in a water molecule?
A
Polar covalent bond
6
Q
What causes the covalent bonds in water molecules to be polar?
A
Electronegativity
7
Q
The unevenly distributed overall charge of a water molecule makes it this
A
Polar molecule
8
Q
The polarity of water molecules allows them to form this type of bond with other water molecules
A
Hydrogen bond
9
Q
What are the four properties of water that contribute to Earth’s suitability for life?
A
- Cohesive behavior; 2. Ability to moderate temperature; 3. Expansion upon freezing; 4. Versatility as a solvent
10
Q
This is the force that holds substances together, as in when hydrogen bonds hold water molecules together
A
Cohesion
11
Q
This is an attraction between different substances, as in when hydrogen bonds hold water to a container
A
Adhesion
12
Q
This is created by the combined forces of attraction among the cohesive and adhesive forces of water
A
Capillary action
13
Q
What are three ways that capillary action allows water to move?
A
- Through porous materials; 2. Through narrow spaces; 3. Upwards against gravity
14
Q
This is a measure of how difficult it is to break the surface of a liquid
A
Surface tension
15
Q
What causes surface tension?
A
Cohesion/adhesion below surface of liquid
16
Q
This causes water to have an unusually high surface tension
A
Hydrogen bonding
17
Q
Can some organisms take advantage of water’s surface tension?
A
Yes
18
Q
These are compounds that lower surface tension
A
Surfactants
19
Q
What are the two parts of a surfactant molecule?
A
Hydrophobic and hydrophilic parts
20
Q
Which part of a surfactant molecule often has a charge that interrupts bonds?
A
Hydrophilic part
21
Q
What are five ways in which surfactants may act?
A
Detergents, wetting agents, emulsifiers, foaming agents, and dispersants
22
Q
What are two ways that water moderates temperature?
A
Absorbing heat from warmer air and releasing heat to cooler air
23
Q
Is the temperature of the water greatly affected when it absorbs or releases heat?
A
No
24
Q
This is the energy of motion
A
Kinetic energy
25
This is the kinetic energy associated with random motion of atoms/molecules
Thermal energy
26
Is 'heat' the same thing as 'temperature'?
No
27
This is a form of energy that moves from hotter to cooler regions, aka energy in transit
Heat
28
This is the average measure of kinetic energy in molecules, aka thermal energy
Temperature
29
Does temperature increase when molecules are heated?
Yes
30
This is the amount of heat required to alter one gram of a substance's temperature by one degree Celsius
Specific heat
31
What is the specific heat of water?
1 calorie
32
Water resists temperature changes because of this
High specific heat
33
Why does water have high specific heat?
Hydrogen bonds
34
What happens to heat when hydrogen bonds are broken?
Heat is absorbed from environment into the water
35
What happens to heat when hydrogen bonds are formed?
Heat is released into the environment from the water
36
The high specific heat of water minimizes temperature fluctuations to within limits to permit this
Life
37
Do aquatic organisms commonly experience drastic temperatures changes?
No
38
What are three important roles of heat in bodies of water?
1. Controlling stratification throughout the year; 2. Relation to the metabolism/physiology/behaviors of aquatic organisms; 3. Influencing how chemicals/metals dissolve in water
39
This is the mass per unit of volume of a substance, or how closely packed "stuff" is within a given area
Density
40
Why does ice float in liquid water?
Hydrogen bonds in ice are more ordered, making the ice less dense than the liquid water
41
At what temperature does water reach its greatest density?
4 degrees C
42
If ice sank, would life be possible on Earth?
No
43
Are hydrogen bonds between water molecules more stable in ice or liquid water?
Ice
44
This is a liquid that is a completely homogeneous mixture of substances
Solution
45
A substance that is this has the same uniform appearance and composition throughout
Homogeneous
46
This is the dissolving agent of the solution
Solvent
47
This is a substance that is dissolved
Solute
48
This is a solution in which water is the solvent
Aqueous solution
49
Why is water a versatile solvent?
Polarity
50
When an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called this
Hydration shell
51
These interactions allow water to dissolve nonionic polar molecules
Van der waals interactions
52
What are four commonly dissolved solutes in water?
Bicarbonate; Calcium; Silica; Sulfate
53
This common water solute is a natural mineral component, found in limestone
Bicarbonate (HCO3)
54
Bicarbonate acts as this in water to control pH
Buffer
55
This common water solute is leached by weathering from soils and rocks
Calcium (Ca)
56
This common water solute is needed in animal diets
Calcium
57
This common water solute dissolves from sand, rock, and minerals
Silica (SiO2)
58
This common water solute is required by algae and plants for growth
Silica
59
This common water solute is leached by weathering from soils and rocks
Sulfate (SO4)
60
This common water solute can change pH and feed bacteria
Sulfate
61
What is a human source of sulfate in aquatic systems?
Sewage/industrial discharges
62
This is the way that substances move through water
Diffusion
63
What are four things that diffuse through water?
Nutrients, gases, contaminants, heat
64
What is the primary influencer of diffusion?
Concentration gradient
65
Which way do substances diffuse along a concentration gradient?
From high to low
66
What are five factors - other than concentration gradient - that affect diffusion of substances through water?
1. Advective transport; 2. Temperature; 3. Molecule size; 4. Presence of other molecules; 5. Organism movement
67
This is when diffusion of substances through water is affected by the movement of water or the movement of other things in the water
Advective transport
68
How does temperature affect diffusion?
Increasing temperature increases diffusion
69
How does molecule size affect diffusion?
The larger the molecule, the slower it diffuses
70
How does the presence of other molecules affect diffusion?
Some molecules can absorb other molecules and prevent them from diffusing
71
How does organism movement affect diffusion?
Organisms can spread material around as they move
72
What is the equation for Fick's Law?
J = D*(C1-C2)/(X1-X2)
73
What does J stand for in the equation for Fick's Law?
Diffusion rate (Diffusion flux)
74
What does D stand for in the equation for Fick's Law?
Diffusion coefficient
75
What does C stand for in the equation for Fick's Law?
Concentration
76
What does X stand for in the equation for Fick's Law?
Distance
77
What law is expressed with this equation: J = D*(C1-C2)/(X1-X2)
Fick's Law
78
What does the equation for Fick's Law determine?
Rate of diffusion (J)
79
Diffusion rate increases with what two factors?
Larger difference in concentrations and shorter distances
80
How is diffusion affected by fluid identity?
Diffusion slows with increased viscosity
81
How is diffusion affected by mixing?
Diffusion slows with increased stratification
82
How is diffusion affected by solid objects?
Diffusion slows as flow boundary layers are created over solid objects
83
What are the two types of diffusion?
Molecular diffusion and transport diffusion
84
This type of diffusion is caused by the thermal movement of molecules
Molecular diffusion
85
Is molecular diffusion more influential for larger or smaller molecules?
Smaller molecules
86
Does molecular diffusion increase with temperature?
Yes
87
Does molecular diffusion happen quickly?
No
88
Is molecular diffusion important for small or large organisms?
Small organisms
89
This type of diffusion is caused by water movement
Transport diffusion
90
Does transport diffusion dominate over molecular diffusion?
Yes
91
Does transport diffusion happen very near to the surface of objects?
No
92
Does transport diffusion happen quickly?
Yes
93
Is transport diffusion important for large or small organisms?
Large organisms
94
Does diffusion happen faster with increased turbulence?
Yes
95
What are three ways turbulent flows are important in water systems?
1. Increase transport diffusion; 2. Dominates over molecular diffusion; 3. Strong force in water columns of lakes/wetlands/groundwater streams
96
What are three contributing factors to diffusion in sediment?
1. Mean path length; 2. Sediment pore size; 3. Characteristics of diffusing molecule
97
This notorious molecule is hydrophobic and binds to the sediment in aquatic systems
DDT
98
These need to move across membranes into the interior of organisms
Gases
99
Do large or small organisms have more difficulty diffusing gases?
Large organisms
100
Why do large organisms tend to have slower metabolisms?
Because they have slower gaseous diffusion rates
101
Why do large organisms have more difficulty in diffusing gases?
Their surface to volume ratio is lower
102
On a small scale, this is unlikely and molecular diffusion dominates
Turbulent mixing
103
Some small organisms have strategies to cause this to increase gas diffusion
Turbulence
104
Light penetrates further through the water depending on this
Water clarity
105
What are four ways sunlight can be altered before entering the water?
1. Reflected by atmosphere; 2. Absorbed/scattered by particles in atmosphere; 3. Reflected by clouds; 4. Reflected by water surface/snow
106
What are four things that can happen to light in the water?
1. Scattering by water or suspended matter; 2. Absorption by water, dissolved materials, particulates, sediment; 3. Backscattering to the surface; 4. Attenuation with depth
107
This is the logarithmic decrease of light intensity through water
Attenuation
108
What are three materials in the water that can contribute to attenuation?
Dissolved compounds, higher productivity, suspended materials
109
What is the equation for the Light Attenuation Coefficient?
n = lnL1-lnL2/Z2-Z1
110
What does L stand for in the Light Attenuation Coefficient equation?
Light intensity at a point
111
What does the Z stand for in the Light Attenuation Coefficient equation?
Depth at a point
112
What is the equation for the percentage of light transmitted through water?
% transmission = 100*L2/L1*(Z2-Z1)
113
These systems have high productivity and suspended materials
Eutrophic systems
114
These systems have intermediate levels of productivity and suspended materials
Mesotrophic systems
115
These systems have low levels of productivity and suspended materials
Oligotrophic systems
116
This tool is a black and white disk of known area that is used to measure light in water
Secchi disk
117
What are three measures of light in water?
Turbidity, total dissolved solids (TDS), light attenuation
118
The amount of light in an aquatic system determines the depth of this
Productivity
119
This is how much light is lost and how rapidly it is lost with increased depth in the water
Extinction coefficient
120
These systems have a small extinction coefficient with large depth
Oligotrophic systems
121
These systems have a large extinction coefficient with shallow depth
Eutrophic systems
122
The attenuation of light is different for each of these
Light wavelengths
123
Does a longer wavelength of light have less energy?
Yes
124
Would red or blue light disappear faster with depth of water?
Red
125
Why does water have a relatively high boiling point?
Hydrogen bonds need a lot of energy to be broken
126
What are six factors that affect water temperature?
1. Sunlight; 2. Transfer from land; 3. Water depth/velocity; 4. Amount of shade; 5. Dissolved substances in water; 6. Thermal pollution
127
What is by far the most important facto in affecting water temperature?
Sunlight
128
What is the equation for Fick's Law regarding heat "diffusion flux"?
Jq = K * (T1 - T2)/(X1 - X2)
129
What does Jq stand for in the Fick's law equation for heat diffusion flux?
Heat flux
130
What does K stand for in the Fick's law equation for heat diffusion flux?
Coefficient of thermal conductivity
131
What does T stand for in the Fick's law equation for heat diffusion flux?
Temperature
132
What does X stand for in the Fick's law equation for heat diffusion flux?
Distance
133
This is greatest with large temperature gradients over small distances
Heat diffusion
134
What are three ways heat is gained by a body of water?
1. Solar radiation; 2. Diffusion from atmosphere or ground; 3. Warm water flowing into system
135
What are six ways heat is lost from a body of water?
1. Reflection of water surface; 2. Back radiation; 3. Evaporation; 4. Diffusion to cooler ground; 5. Cold water flowing into system; 6. Evaporation, condensation or shading from plants
136
What is the equation for heat budgets?
S = Rn - E - H - Q
137
What does S stand for in the equation for heat budgets?
Storage rate of heat in water
138
What does Rn stand for in the equation for heat budgets?
Net radiation (sunlight)
139
What does E stand for in the equation for heat budgets?
Evaporation
140
What does H stand for in the equation for heat budgets?
Heat transfer from conduction
141
What does Q stand for in the equation for heat budgets?
Heat transfer from advection (movement in or out of water)
142
What is calculated by the equation S = Rn - E - H - Q?
Heat budget of a water body
143
This is known as the "abiotic master factor"
Temperature
144
What are four things that increase when water temperature increases?
1. Diffusion; 2. Rate of chemical reactions; 3. Toxicity of specific metals; 4. Water expansion
145
What are three things that decrease when water temperature increases?
1. Dissolved gases; 2. Photosynthesis rates; 3. Water contraction
146
This is the tendency of lakes to form separate and distinct thermal/density layers at specific times of the year
Stratification
147
What are the three levels of lake stratification?
Epilimnion, metalimnion, hypolimnion
148
This is the shallow surface layer of a lake
Epilimnion
149
This is the transition layer of a lake
Metalimnion
150
This is the deepest lower layer of a lake
Hypolimnion
151
What is the warmest layer of a lake?
Epilimnion
152
In what layer of a lake is the thermocline?
Metalimnion
153
This is the point of greatest temperature difference in a lake
Thermocline
154
What is the coldest layer of a lake?
Hypolimnion
155
What is the least dense layer of a lake?
Epilimnion
156
What is the densest layer of a lake?
Hypolimnion
157
During what seasons do temperate lakes turnover and mix?
Fall and spring
158
During what seasons do temperate lakes tend to stratify?
Winter and summer
159
What are three ways that humans can affect temperature?
Impervious surfaces, dams, and thermal pollution
160
These are hard surfaces that absorb and store heat
Impervious surfaces
161
Impervious surfaces transmit heat to local stream systems during this process
Runoff from rain
162
These change the natural seasonal patterns of temperatures through releases
Dams
163
This happens when municipal or industrial effluents discharge into streams at higher temperatures
Thermal pollution
