Chemistry in the Community. Safety Always use small containers easily handled. Never mix chemicals...
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Mr. Olson Chemistry in the Community
Chemistry in the Community. Safety Always use small containers easily handled. Never mix chemicals without teacher’s permission. Add acid to water, never
Safety Always use small containers easily handled. Never mix
chemicals without teachers permission. Add acid to water, never
reverse. Work tray will help contain spills. When selling
chemicals, only if directed to do so, hold away from face and wave
scent towards nose. Read all labels. Hold coin-top of stoppers
between fingers and replace as soon as possible. Notify teacher to
clean up spills.
Slide 3
Make sure hose fits securely and has no cracks. Only heat open
containers. Always use tongs, never bare hands. Check glass ware
for scars or cracks. Never shake thermometer. If thermometer
breaks, let teacher know. Use thermometer only in temp range
recommended. Lay thermometer down on towel to cool away from
lab.
Slide 4
No loose sleeves or clothes in lab. Fuzzy sweaters can easily
start on fire. No open shoes, leather closed shoes. ALWAYS WEAR
SAFETY GLASSES! Fabrics strong and sturdy Lab apron. Long pants.
Tie long hair back. Take off jewelry. No fooling around.
Slide 5
Stand on stool if needed. Immediate medical attention after any
cut. Rinse eyes for 15 minutes if you get chemicals in them. Rinse
chemicals from hands Get naked for shower. Put out fire in safety
shower. No eating or drinking in lab.
Slide 6
Defined: The process of clarifying water in order to make it
suitable for release into the environment, or for making it fit for
human consumption (potable). Water quantity has its limits: Water
supplies on the earth are finite. Current distribution of water is
as follows Oceans (saltwater) = 97.2% FRESH Water = 2.8% Glaciers =
2.11% Rivers =.0001% Lakes =.009% Atmosphere =.001% Groundwater
=.62% Water Treatment
Slide 7
* With fresh water supplies being so small, water quality is
important. This means that water must be cleaned before we use it,
and before discharging into the environment it must be
cleaned.
Slide 8
PROCESS OF WATER TREATMENT Definition: To clarify water; that
is to remove suspended material, is critical to improving the
waters quality.
Slide 9
Stages of Water Treatment 1.Large Solid Removal: A screen or
grate is used to separate large rocks, trees, etc from water
2.Coagulation, Flocculation, and Sedimentation: A chemical
(coagulant) that will cause large suspended particles to form
clumps (floc) is added to water. This floc will float or settle out
(sedimentation) 3. Filtration: Percolation of water downward
through porous material and suspended materials get caught and
water passes through. Filter Medial includes sand, gravel, clay,
charcoal and screens. Separation works with large pores collecting
large particles, with smaller pores, collecting small particles.
During filtration, particles may adhere/stick (adsorption) to
filter media.
Slide 10
1.Disinfection: The addition of chemicals, usually chlorine to
water effort to kill pathogens/microbes/bacteria. 2.Dissolved
Solids: These materials will stay with the water because they are
dissolved solids in water. Conductivity is a measure of the ability
of water to conduct an electrical current. Under most conditions
dissolved materials are not removed during water treatment. 3.* To
understand Riverwoods Problem: The people of Riverwood must
understand the property and behavior of water.
Slide 11
PHYSICAL PROPERTIES OF WATER 1.Water is clear, odorless, and
tasteless. Any color, taste or smell is given to water by some
outside source. 2.Water is capable of dissolving many different
substances. It is defined as the universal solvent. Any substance
dissolved in water is said to be in an aqueous solution. 3.*
Electrolytes: Act as a conductor of electricity
Slide 12
4. Water is a liquid at room temperature 5. Water has a density
of 1g/mL. This doesnt change much as water changes phases. The only
unique condition occurs when water freezes. Its behavior at 0 C is
unique to water and nothing else. It expands. 6. Water has a narrow
range of temperature between its freezing/melting point and boiling
point (0-100 C) 7. Polluted water is a mixture. This means some
materials are dissolved in water forming a solution. While others
are not dissolved and exist in suspension or as a colloid.
Slide 13
Distillation Apparatus
Slide 14
MOLECULAR WATER 1.Composed of elements hydrogen and oxygen
2.Hydrogen and oxygen combine in a 2:1 ratio 3.As water is formed,
each hydrogen atom gives up one electron and the oxygen accepts 2
electrons 4.Molecular formula for water is HO
Slide 15
H H O 105 Polar Molecule Structural formula for water is:
Slide 16
Because water has positive and negative poles, this allows for
the formation of some new bonds too. These bonds are called
HYDROGEN BONDS. Hydrogen Bonds are weak forces that allow two water
molecules to be attracted to each other. (See Figure)
Slide 17
The outcomes of hydrogen bond formation are the following:
1.Causes water to behave differently than other materials *Water
expands when it becomes ice 2.Requires that water absorbs more
energy to change phases(states) *Water will absorb or release huge
amounts of heat. *Temp will remain constant 3.Allows water to
remain a liquid most of the time O C = Freezing/Melting, 0-100 C=
Liquid, 100 C = Boiling Point
Slide 18
**As matter changes phases (states), heat energy must be
absorbed
Slide 19
SolidLiquidGas Heat Gain KE Increase KE increase Temp Increase
*At the phase change, that is the time when a solid is converting
to a liquid and a liquid is converting into a gas, Kinetic Energy
remains unaffected. Particle motion doesnt change; as a result the
temperature doesnt change. The only factor that changes is the
Potential energy. Potential Energy must increase to break hydrogen
bonds!
Slide 20
TEMPERATURE: Measure of average kinetic energy of particles in
motion, therefore temperature doesnt change during phase change.
There is no change in the kinetic energy of the material
(water).
Slide 21
Boiling Condensing Solid / Melting Point Boiling Point Liquid
-50 C 0 C 100 C 150 C Heat Added Heating- Cooling Curves GasGas
Freeze Gas Temperature ( o C) Energy Added
Slide 22
Phase Change Measurements: 1. Latent Heat of Fusion: A measure
of heat needed to melt one gram of matter (water) to a liquid. For
water this is a lower volume, because hydrogen bonds are needed to
be broken; therefore less energy. 2. Latent Heat of Vaporization: A
measure of heat needed to vaporize one molecule of matter (water)
to a gas. More hydrogen bonds need to be broken; therefore this
value is greater for water. Remember at both melting and
vaporization TEMPERATURE DOESNT CHANGE!!!!!!!!!! 3. Specific Heat:
The amount of energy need to raise the temperature of one gram of a
substance one degree Celsius.
Slide 23
Slide 24
Ground Water -Ground Water can be defined as water found in
cracks and pores of a rock below the earths surface -The rock
through which water can be stored and transmitted (flows, or is
pumped out of) is identified as an aquifer. Aquifers can be
described by the following conditions: 1. Dimensions: -Vertical
Dimension: Depth below ground level. Range from 0 feet -100s of
feet. -Horizontal Dimension: Width of the water table. Ranges from
100s of miles. 2. Production: Gallons per mile. 3. Age: Period of
time the water has been present in the aquifer (days or years.) 4.
Movement: -Vertical Movement: Recharge of ground water. -
Horizontal Movement: water flows down hill water will follow
contour of the land.
Slide 25
Ground Water Terminology Water Table: The top of an unconfined
aquifer; indicates the level below which soil and rock are
saturated with water. Confined Aquifer: An aquifer that is bounded
above and below by non permeable layer that transmits water
significantly more slowly that an unconfined aquifer. The water
will rise above the top of the aquifer because the confine aquifer
is under pressure. Unconfined Aquifer: An aquifer in which the
upper boundary is the top of the water table. Permeable Layer:
Portion of aquifer that contains rock material that does not allow
water to penetrate freely.
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Ground Water Terminology Impermeable Layer: Portion of aquifer
that contains rock material that does not allow water to penetrate;
often forms the base of unconfined aquifers and the boundaries for
confined aquifers. Zone Of Saturation: The part of water bearing
formation in which all spaces between soil particles and in rock
structures are filled with water. Zone Of Aeration: Portion of
unconfined aquifer above the water table where the pore spaces
among soil particles and rock formations are filled with air.
Slide 27
Aquifers Of Wisconsin Sand And Gravel Aquifer 1.Covers most of
Wisconsin except the south west part of the state (Driftless Area.)
2.Created when the glaciers carried debris across the state and
ancient rivers deposited material. 3.Excellent source of water and
is used extensively for irrigation. 4.Because of its nearness to
the surface it can easily be contaminated.
Slide 28
Aquifers Of Wisconsin Eastern Dolomite(Limestone)Aquifer
1.Sandwiched between the sand/gravel aquifer and a confining layer
of (Maquoketa) Shale. 2.Covers the eastern most part of the state
from Door County to the Wisconsin and Illinois border. 3.Because of
the fractures found in Dolomite the yield of water can vary.
4.Prone to contaminate (again because of the fractures) where ever
the water lies to close to the surface.
Slide 29
Aquifers Of Wisconsin Sandstone and Dolomite Aquifer 1.Supplies
most of the water for Wisconsin. 2.Covers the entire state except
for the North and Central part of the state. * Excellent aquifer
since both rocks are very porous, and or permeable
Slide 30
Aquifers Of Wisconsin Crystalline Bedrock Aquifer 1.Made up of
the oldest rock in the state. 2. Found as the deepest rock in
Wisconsin. 3.Supplies water for North and Central Wisconsin.
4.Shallow wells provide good supplies of water. 5.Deeper wells in
the aquifer will yield salty water.
Slide 31
Matter MixturesSubstances -physical combination of matter
-nothing new is made -components maintain their individual
properties -have uniform and definite composition Suspensions
Colloids Solutions Elements Compounds Matter Types Overall
Features
Slide 32
-Most basic part of all matter -A chemical combination of 2 or
more atoms/elements -Represents the building block of all matter
-Its the smallest component is the molecule -Its smallest component
is the atom -Can be broken down into the atoms/elements that make
it up by chemical means -Over 100 different elements/atoms are
known to man Unlike mixtures it has a definite composition Only
form of matter that cannot be broken down into something smaller or
more basic Example from lab H0 after distillaton Example from lab:
none All atoms of a given element are identical with the numbers of
protons(+) and electrons (-) All atoms are electrically neutral
ElementsCompounds
Slide 33
Slide 34
Chemical Bonding
Slide 35
Formation of Ionic Compounds
Slide 36
Formation of Molecular Compounds (Covalent Bonds)
Slide 37
Polar Covalent
Slide 38
Atomic Structure Average atomic mass 6p + + 6n = 12 (mass
number) 12 amu (atomic mass units) Chemical Symbol Element Name
Atomic Number = ( number of protons, also number of electrons) *
Mass Number = (Protons + Neutrons ) round atomic mass to whole
number
Slide 39
Atomic Structure of Carbon Electron Proton Neutron
Slide 40
Reading and Writing Formulas Writing Chemical Formulas
Background: Formulas consist of: Element and Element A B (Or)
Element and Polyatomic Ion A BC
Slide 41
Ion: Multiple elements combined that behave like one element.
When elements want to combine they must lose or gain electrons.
Losing electrons Cations Positive Charge Ex: Na + (+) Gaining
electrons Anions Negative Charge (-) Ex: Cl - Polyatomic Ions: 2 or
more elements behaving as one element that has a positive or
negative charge.
Slide 42
Procedure 1.) Write down the symbols of the elements in the
compound, as seen on the periodic table Potassium oxide = K O 2.)
Place charges next to each symbol as seen on page 33. K O 2 3.)
Crisscross the charges K O K O (never write the number 1)
(*subscript = tell the number of atoms present : 2 atoms of
potassium one atom of oxygen) Ex. Magnesium Phosphate Mg PO
Metal
Slide 43
Mg 3 (PO ) 2 *Answer to chemical formula for Magnesium
Phosphate
Slide 44
CationAnionFormulaName KClKClPotassium Chloride Ca SO CaPO NH
(NO)Ammonium Nitrate Al (SO) Magnesium Hydroxide Calcium
Carbonate
Slide 45
Reading Formulas: *If only 2 elements are present: 1.) Read the
first element as seen on the periodic table. 2.) Change the ending
of the second element to -ide- Al S = Aluminum Sulfide
Slide 46
Look for the metal! *If three or more elements are present: 1.)
Read the first element listed as seen on the periodic table. 2.)
The second item listed will be a polyatomic ion, and read it as
seen on table on p. 33 Zn Co = Zinc Carbonate
Slide 47
Reactants Products Subscript Coefficients Yield State Mg Cl
(aq) + 2 Na (s) 2 NaCl (aq) +Mg (s) In a water solution Chemical
Equation
Slide 48
Solution Characteristics 1)All solutions have a solute and
solvent. a.)Solute: Materials being dissolved(oxygen sugar
b.)Solvents: Material that carries out the dissolving
process(water) 2)Temperature plays a big role in determining the
quantity of solute that will dissolve. 3)At higher temps more
solute will dissolve 4)Solubility: The amount of solute that will
dissolve in 100 g of water at a given temperature. 5)Therefore at a
given temperature, water will dissolve only a certain quantity of
solute. (See graph 46) 6)Saturation: The condition created when a
solvent is dissolving the max amount of solute possible at a given
temperature. 7)Unsaturated: A solvent is dissolving less solvent
than it can normally hold at a given temperature 8)Supersaturated:
A solvent contains more solute that in can normally hold at a given
temperature
Slide 49
Solution Concentration Terms like saturated, unsaturated, and
super saturated are sometimes inadequate to describe solution
concentration. RIVERS AS SOLUTIONS 1.Water in rivers dissolves many
substances, therefore allowing for many ions to be released into
the water. 2.Common maters found in river water Limestone bedrock,
upon dissolving will release calcium and magnesium ions into water.
3.Salts are naturally found in soil, and they will release
different ions into water. 4.Road salt from last year is a source
of chloride ions 5.Fertilizer and animal wastes are sources of
nitrates and phosphates 6.Photosynthesis will produce oxygen
7.Respiration and decay will produce carbon dioxide and lower
oxygen amounts 8.Acidic gases dissolve in water and will lower
pH
Slide 50
Balancing Equations *Equations consist of 2 parts: 1.Reactants:
Materials found left of the arrow. 2.Products: Materials found
right of the arrow. 3.To balance an equation, place coefficients
(numbers) in front of either reactants or products, in order to
balance the number of atoms on both sides of the equation.