UCE CHEM136 ENSC136 Flashcard

1m3=_L
103L=_m
1L=_cm3
103cm3=1L
1M=
1mole/L
Water Distribution on Earth

97% Ocean

2% Ice Caps

1% Ground Water

.01% lakes

.001% Atmosphere

Residence time of Atmosphere
10 days
Residence time of the ocean
3000 years
trade winds
East to West at low latitudes
Westerlies
West to East at mid-latitudes

Direction of wind in the Upper Hemisphere

 

Lower Hemisphere

Upper Hemisphere = clockwise

 

Lower Hemisphere = counter clock wise

Direction of ocean in the Upper Hemisphere

 

Lower Hemisphere

Upper Hemisphere = clockwise

 

Lower Hemisphere = counter clock wise

Atmosphere is heated from?
below
Ocean Temp

75-200m = 18C

1000m – 3500m = 3C

 

pycnocline
sharply decreasing density that parallels the thermocline
Describe Salt Water Currents

sinks in thw norwegian seadown, down the atlantic, up into the pacific and indian ocean.

 

Exchange rate 100 – 1000 years

Chem that are well mixed and not well mixed

 

Residence/Mixing time?

Residence Time >>> Mixing Time =uniform concentration

 

Residence Time < Mixing Time = Non uniform

 

LAKES

 

Residence time for any chemical cannot be longer than the water renewal time

 

Ocean Salinity

amount

 

Depth Chart

35 parts per thousand 35g/kg

 

[image]

Lake and River Salinity
0.1%
Major Cations
Na+,K+,Mg2+,Ca2+
Major Anions
Cl-,SO42-, HCO3
Nutrients
H4SiO4,NO3-, PO4
Trace Metals
Cu2+, Zn2+, Cd2+, Pb2+
Expected Solid or solution phase?
Monovalent ion and Large Divalent have weak ionic bonds and are expected to be in solution and have long residence times
Only homogenious ocean ions
Anions and Cations
Absorbed particles in particulate matter have ____ residence times
short residence times
Ions that have a seasonal behavior in a lake
Cu, Ni, Cd are recycled behavior in summer and scavendeg in the winter
Equilibrium constant vs. Temp & Pressure

Increase Temp = Increased eq. Constant = more products only if endothermic (gets cold)

 

Increase Pressure = increased eq Constant = more products

Typical Lake Concentration Curve
[image]
Typical Lake Temp Curve
[image]

Ocean Acumulated Curve

 

Residence time

 

Ions

[image]
Ocean Trace Metals Curve
[image]
Lake Nutrients Curve
[image]
Ocean Oxygen Curve
[image]

Recycled Curve

 

Residence Time

 

Ions

[image]

Ocean Scavenged curve

 

Residence Time

 

Ions:

[image]

Ocean Temp Curves

 

Low mid high latitudes

[image]

Acid Base Reaction

 

k name

Products are OH- or H+

 

k=dissociation Constant

Complexation

 

k name

components are assembly into a product

 

k= stability constant

Dissolution Precipitation

Products are a breakdown of starting material

 

k= soulubility products

Adsorption
k= adsorption constant
activity coefficient of a solid
1
Solubility

K High Ionic Strength = K

 

K low Ionic Strength =Kd

 

K>Kd = more soluable in High

K<Kd = more soluable in low

activity coefficient of ions in solution
always less than one. = minerals are more soluable in high ionic strength than low ionic strength

Henry’s Law Constant Vs.

;

Temp

;

Molecular Weight

;

solubility

;

;

HLC increases with decreasing Temp

;

HLC increases with increasing molecular weight

;

Large molecules are more polarized = more surface area to interact with water = prefer solution phase

;

salt reduces binding energy means more gas in freshwater

CO2 ___ in water
ionizes
How to measure partial pressure

(atm)[]

;

sealevel O2

1atm*21% = .21atm

water-air equilibrium

eq is water surface

;

flows high to low so if

;

[A] in soultion ; eq then fluxes to air and is super saturated

;

[A] in soultion ; eq then fluxes to water and is subsaturated

;

[]decreases with increasing temp

Transport Velocity

vs

diffusion coefficint

;

film thickness

increases with diffusion coefficient

;

decreases with film thickness

film thickness
thinkness decreases with increased windspeed
CO2 concentration is greatest @

Equatordue to upwelling, everywhere else is subsaturated

;

Lakes are supersaturated especially during spring

Metabolic Processes uptake these elements
C,H,O,N,P,Si
These compounds are depleted on the surface waters due to photosynthesis

CO2, H3SiO4, NO3, PO4

;

increase with depth

O2 levels and depth
Large number at surface, depeletes in depths
Shells are made of
SiO2 and CaCO3

Type of Shell Produced

;

Coccolithophorida

Foraminifera

Pteropods

Diatoms

Radiolarians

Coccolithophorida = Calcite

Foraminifera = Calcite

Pteropods = aragonite

Diatoms = Opal

Radiolarians = Opal

Limiting Nutrient in Oceans
Phosphorus, Nitrogen, Iron in Austrailia, Silica in South America
Letter representing element loss into sediments
f
Letter representing element loss into deep waters
g
Fraction of element lost during each mixing cycle
f*g
Ocean Mixing time Letter
TM = 1000 years
Biolimiting features

High g =; high level of mixing

Low f =; low loss into sediments

Residence time = 10^5 – 2*10^4

;

Cs/Cr very different from Cd/Cr

Biointermediate Features

g around .7-0

f = .1

Residence Time = 10^4 – 8*10^5

Cs/Cr close to Cd/Cr

;

Biounlimited Features

no g

no f

Residence Time = 6*10^7 – 1*10^8

Cs/Cr = Cd/Cr

Lake names for surface, deep, and sediments
Epilimnion, Hypolimnion, sediements
Acids and Bases = H+

Acids give H+

Bases recieve H+

Strong Acids

HCl

H2SO4

HNO3

Titration Volume Equation
(Vi+Va)[acid]=(Vi)[base]
H2CO3* Equilibiria

H2CO3*-; HCO3 + H+

HCO3 -; CO32- + H+

H2O -; H+ + OH

H2CO3* Alkalinity Equation
[ALK]= [HCO3] + 2[CO32-] +[OH] – [H+]
Soluibility and pH change
Metals: solubility increases as pH increases
saturation, rainy vs. arid regions

Rainy: low concentrations of ions are undersaturated with respect to CaCO3, CO2 added by decomposing matter causes further dissolving of CaCO3

;

Arid: High ion concentration and are supersatured with respect to CaCO3

Types of Weathering and how they are done

Physical Weathering – wind abrasion, ice, plant rooots

Chemical Weathering – Dissolved species into water

;

Chemical Weather is effect by

pH

Temperature

Water Flow

Solubility

Vegatation

pH: Low pH Increases weathering

;

Temperature: Increases weathering

;

Water Flow: Increases weathering

;

Solubility: high Sol. Increases weathering

;

Vegatation: Releases organic acids into soil and Increases weathering

Rock Types and Description

Igneous – crystallization from melted rock at high temps

;

Sedimentary – Sedimentation in water formed by various debris

;

Metamorphic – Recrystallization of igneous and sedimentary at high temp and pressure without melting

;

75% of surface is sedimentary

Rock classes and dissolved in water

Evaporites: 17%

Carbonate: 38%

Silicates: 45%

;

*Lower % is better for abundance

SiO4 charge and Structure

Si = 4+

O = 8-

Total = -4

;

More SHARED Oxygen is better in crystal

SiO2 is strongest

SiO4 weakest (most soluble)

Riverflow highest and lowest

highest: low ; high latitudes

Lowest: mid latitudes

Rivers

Inorganic Particles

Major Dissolved Species

Inorganic Particles: Al, Fe, Si, Ca

Major Dissolved Species: Ca2+, Na+, Mg2+, K+

Things that increase sediment load

;

Things that reduce sediment load

High elevation

easily eroded materials

heavy rainfall

;

;

large drainage areas ; lakes reduce

Total concentration of dissolved ions in rivers
100mg/L
Red Clay
Covers entire ocean floor, Thickest deposits near mouths of rivers and along coast, composed of silicate minerals
CaCO3

formed by the desposition of phytoplankton and zooplankton, If not red clay than this or opal, Organsims that produces this are much more uniform; thus more distributed throughout oceans,

;

made by organisms that use nitrates and phosphate but not silica making them soft and easily dissolved in surface waters and distributed

;

some waters are under/over-saturated with respect to CaCO3 determining dissolving

;

dominate atlantic sediments

;

16% preserved in sediments

Opal

formed by the desposition of phytoplankton and zooplankton, If not red clay than this or CaCO3,

;

highly nonunifrom, near upwelling since silica is not recycled easily. most in equator, antartica and pacific. LEAST in atlantic

;

Ocean is undersaturated with repsect to opal so always will dissolve

Hard Sphere Ions

Low Polarizability

Electrostatic Bonding

Na+

Soft Sphere Ions

High Polarizability

Covalent Bonding

Cu+

Metal/Ligand Absorption Curve

[image]

;

;

[] Absorbed

Organic Matter and pH
Organic matter absorption increases at low pH and decreases as pH rises

Oxidation Number

O

H

;

Reduced travel =

Oxidized travel =

O2 = 0

O = -2

H = +1

;

;

Reduced travel = more –

Oxidized travel = more +

Release of absorbed particles
When particles enter deep water that is low in oxygen metal return to solution phase and diffuse back to surface where they are reabsorbed again.

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