Chapter 3: Physical and Chemical Properties of Water Flashcards
Memorize this chapter
What make water unique?
Water’s shape: covalent bond and polar molecules
Water can be found in all three states at the same time
1) Has a high specific heat
2) Cohesion/adhesion
3) Surface tension
4) Density of solid with liquid
5) A great solvent
6) Act as a buffer
Why is liquid water so important?
1) Life depends on chemical/physical properties
2) Liquid water critical and unique
3) All organisms mostly water
4) Marine organisms 80% or more
Nature of pure molecular water
Matter = atoms combine into molecules
Water
2-H atoms attached to 10 atom by strong covalents bonds and sharing electrons
Water is sticky: hydrogens bonds
weak attraction between water molecules and not so true “bond” because not sharing electrons
Water is a polar molecule
Most important reason why the exists on this planet
Water states are listed here:
1) Solid
2) Liquid
3) Gases
States of pure water
High heat = high breaking of H-bonds = high volume = low density
State of pure water = continuing heating
Evaporation
Boiling is when all water molecules enter
Vapor state at once
Pure water’s density is greatest at
4 degrees celcius
Somewhere pure water’s between
4 degrees celcius - 0 degree celcius, density decreases = ice floats and why?
To help maintain life on planet
Heat and water
1) Water has a high heat capacity
2) High heat of evaporation = evaporative cooling
3) Impt regulator of temperature
Pure Water as a Solvent
1) H20 dissolves salt and polar molecules = univeral solvent
What are salt?
Ions connected by ionics bonds
Water surrounds ions
Dissolves ions
Properties of Seawater: Sources of dissolved ions in the oceans
1) Weathering of rocks
2) Interior of the Earth
3) Sodium (NA+) and Chloride (Cl^-) make up 85 % dissolved ions
Salinity
Total amount of salt dissolved in seawater
Average sea water salinity
35%
Salinity changes when pure water is
Added and Removed
Density depends most on
Temperature and somewhat on salinity
Temperature range from
-2 degrees celcius + 30 degrees celcius
Deep ocean temperature measured by
Reversing thermometer, electronic probes
What is thermoclines?
Temperature
What is haloclines?
Salinity
What is pycnocline?
Density
In area with very strong thermoclines, there little mixing between
Surface water and deep water
Seawater contains
O2, N2, and CO2
Gases dissolves more easily in
Cold water
O2 comes from atmosphere and primary producers in
The ocean
O2 highest in upper 10-20 m (02 Max Layer) and lowest between
500-1000 m (O2 min zone)
High CO2 with depth because of the
Respiration plus with decomposition at lower surface because photosynthesis and mixing
CO2 reacts with water to form
Carbonic acid
Carbonic acid dissociates to form H^+ and bicarbonate (HCO3) to creates
Acidic environment
Seawater is naturally slightly alkaline (basic) because of
NA^+, K^+, Ca^2+ and pH ranging from 7.5 - 8.4
Warmer water holds
Less oxygen and carbon dioxide
Seawater somewhat
Transparent
Most sunlight reflected, rest absorbed and scattered by
Water and particles
Blue and green least absorbed, followed by
Violet, yellow, orange, and red is most absorbed
Coastal waters are less
Transparent and greener
Photic zone extends to where light intensity is
1% of the surface light intensity
At sea level, the ocean under
Atm (1) of pressure
With each 10m of depth, another
Atm added
Motion in the ocean: Surface circulation having:
1) Coriolis effect
2) Wind patterns
Coriolis effect
1) Deflected direction an object moves based on rotation of Earth
2) Northern hemisphere = left
3) Southern hemisphere = right
Wind patterns
1) Solar energy
2) Rising air at equator
3) Trade wind
4) Westerlies (middle latitude)
5) Polar easterlies
Surface currents
1) Move at 45 degrees to winds (Ekman Spiral) were net transport (90 degrees) gyres
2) Important in transporting heat over earth
3) El Nino
Vertical motion: three layered ocean
1) Surface (mixed layer)
2) Intermediate layer (thermocline)
3) Deep (bottom layer)
4) Stratified water column
Stability and overturn with changing seasons
1) Downwelling and upwelling
2) Why important was the upwelling
Great Ocean Conveyer critical for
Mixing water and transporting heat around the world
Great Ocean Conveyer keep us
Alive
Great Ocean Conveyer might be
Breaking down/changing because of climate change and global temperature
Two places for water to sink all the way down for:
1) South of Greenland
2) North of Antarctica
Waves caused by
Wind
Anatomy of a wave were
Crest, trough, waveheight, wavelength, and period
Fetch
The span of open water over which the wind blows
Tsunami
1) Japanese word meaning: harbor wave
2) Not wind generated wave
3) Shifting of seafloor
Japan tsunami
1) 20,000 deaths
2) Shifted Earth on its axis of rotation
3) Shortened day by one microsecond
Tides pull of
Moon and sun
Earth and moon rotate
Around the center of mass between them
Centrifugal force created by rotation is
Balanced by gravitational attraction between earth and moon
Many animals base their lives around
The tides
Every other week is a
Spring tide or a neap tide
Full tidal cycle
24:50 hours
Sun 1/2 as much pull as
Moon
Spring tides
Extremes (new moon and full moon)
Neap tides
Milder (first and third quarter)
Semidiurnal tides
Two equal high and two equal law (east coast, Europe, and Africa)
Mixed semidiurnal tides
Two unequal high and two unequal law (common in Socal)
Diurnal tides
One high and one low (rare, Antarctica)
