Download - 1B. Looking at Water & Its Contaminants
1B. Looking at Water & 1B. Looking at Water & Its ContaminantsIts Contaminants
Learning more about the chemistry of water and how substances interact with water
Do Now: (day 1)
Read Article on pg. 25 and write a paragraph summary addressing: water tests that were performed Concerns Other important information
Do Now (cont.)
Concerns Dissolved oxygen (DO) levels – will test Microorganisms – none present Dissolved matter – must consider amounts
& effect of temperature on solubility – will test
Suspended particles – will test Other Information
No illness – water conservation tips – more water trucked in – 3 day crisis expected
Now what?Now what?
Water experts agree that the fish kill was caused by something either dissolved or suspended in the Snake River.
How can you determine the exact cause? Knowing properties of water & properties
of substances that may be found in it will help.
Knowing language of chemistry will help you communicate your findings.
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Objectives
SWBAT compare and contrast surface tension between water and alcohol
SWBAT define matter and discuss the physical properties of water.
SWBAT calculate density
1B.1 PHYSICAL PROPERTIES 1B.1 PHYSICAL PROPERTIES
OF WATEROF WATER
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Mini- group activity- WKST U1B2
PREDICTION: How many drops of water can a penny
hold without spilling over?
Surface Tension
Water is very common… on EarthWater is very common… on Earth
70% of Earth’s surface covered by oceans – average depth of 3 km (2 mi)
Unmatched by any planet or moon in our solar system
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Matter
MATTER:MATTER: IS ANYTHING THAT HAS MASS IS ANYTHING THAT HAS MASS & OCCUPIES SPACE.& OCCUPIES SPACE.
WATERWATER IS MATTER. IS MATTER.
Let’s think about…
What states of matter can be observed in this winter scene?
Water has Physical PropertiesWater has Physical Properties
Matter can be distinguished by its properties.
Physical properties are those can be observed and measured without changing the chemical makeup of the substance
Ex.- color, odor, density, melting point, boiling point, freezing point.
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Water has Physical PropertiesWater has Physical Properties
Density – Water’s density is 1.00 g/cm3 or 1.00 g/mL at 25oC – varies by temperature Ex. Mini-lab
Freezing Point – 0oC at normal atmospheric conditions
Any others?
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Do Now (day 2)
What physical property of water explains the “sheeting action” under the swimmers right arm?
Objectives
SWBAT identify physical properties of substances
SWBAT differentiate between mixtures and substances and heterogeneous and homogenous mixtures
SWBAT create a concept chart of all types of solutions
Unit 1B.2 p2
Think-Pair-Share WKST
““Pure” WaterPure” Water
“Pure” water is water with absolutely nothing else dissolved or suspended in it
Properties of pure waterClearColorlessOdorlessTasteless
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Substances Dissolve in WaterSubstances Dissolve in Water
Aqueous solutions – water based solutions SOLUTE- substance that is being
dissolved SOLVENT- substance that dissolves
the solute (usually water, in aqueous solutions it is water)
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Substances Dissolve in WaterSubstances Dissolve in Water
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Sample Solute Solvent
Salt Water
Coffee
lemonade
1B.3 MIXTURES & SOLUTIONS1B.3 MIXTURES & SOLUTIONS
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Matter is divided into a mixture or a substance
Mixture: two or more substances coming together but
keeping their individual properties “Foul Water” was a mixture of water, used
coffee grinds, oil, garlic powder, salt
Substance: Definite composition, not physically able to
separate
Types of Mixtures
Homogeneous Mixture: Composition is the same or uniform
throughout
Heterogeneous Mixture: Composition is not the same or uniform
throughout.
2 Types of Heterogeneous Mixtures2 Types of Heterogeneous Mixtures
Suspension – heterogeneous mixture containing large, solid particles that can settle out or be separated by filtration
Colloid – heterogeneous mixture containing particles too small to settle out – cloudy – Tyndall effect
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SolutionsSolutions
All solutions are homogeneous mixtures
A solute dissolves in a solvent to make a solution
Solutions are clear but not necessarily colorless
A conductivity test indicates the presence of dissolved charged particles
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Types of Substances
Elements: One type of atom
Compounds: Two or more types of atoms chemically
bonded together
Do Now
What are the two major types of mixtures?
What is the difference between a suspension and a colloidal dispersion?
Objectives
SWBAT review the differences between types of mixtures.
SWBAT create a concept chart of substances and mixtures and provide examples of each.
SWBAT differentiate between symbol, element, compound, and molecule.
Create a concept chart and write an example of each category.
1B.4 PARTICULATE VIEW OF 1B.4 PARTICULATE VIEW OF
MATTERMATTER
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Particulate LevelParticulate Level
To understand the macroscopic (large scale & readily observed) properties of water, you have to understand water’s behavior at the particulate level – the level of small particles – the level of atoms and molecules
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SubstancesSubstances
Atoms – “building blocks of matter”
Elements – made of one kind of atom
Represented by symbols (H, O, Ne) & sometimes formulas (H2, O2)
Molecules – made of atoms joined together – atoms can be the same or different
Compounds – made of different elements combined together
Represented by formulas (H2O, KCl)
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Refer to your te
xt
and/or handout fo
r
details.
MODELS:MODELS:REPRESENTATIONS OF ATOMS REPRESENTATIONS OF ATOMS & MOLECULES& MOLECULES
These pictures are one kind of model (space filling model).
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Models of WaterModels of Water
“Seeing and Imagining Water” Visit the online site for 1B
http://www.whfreeman.com/chemcomstudent/index2.html
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1B.5 PICTURES IN THE MIND1B.5 PICTURES IN THE MIND
Modeling Matter
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Drawing ModelsDrawing Models
Sample Problem: Draw a model of two gaseous compounds in a homogeneous mixture.
What do you need to know to draw your model?What is a homogeneous mixture?What might a gaseous compound look like?How many compounds are in this mixture?
There is more than one drawing possible.
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Do Now Describe the picture:
1. What type of mixture is this? 2. How many compounds? 3. What state of matter?
Objectives
SWBAT classify pictures as homogeneous, heterogeneous, gas, solid, or liquid.
SWBAT identity the number of different compounds in a substance or mixture
SWBAT draw different mixtures and answer questions related to those pictures
Drawing ModelsDrawing Models
Which of the following drawings best represents a homogeneous mixtures of two gaseous compounds?
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Drawing ModelsDrawing Models
The best answer is “b.”
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• 2 types of molecules are uniformly mixed• Atoms are colored to represent different elements
• Not homogeneous
• 3 different compounds, not 2
“b” & “c” are space-filling models. “a” is a ball-and-stick model. Both are acceptable.
Drawing ModelsDrawing Models
Finish the 7 questions for the B.5 Pictures in the Mind modeling matter activity on pp. 33-34.
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Homework
Pg. 50 #1-4, 6-8, 10
Do Now
Name 4 elements
Where can you find each one?
Objectives
SWBAT understand the requirements for the mole day project
SWBAT determine numbers of atoms in a formula
SWBAT identify elements on the periodic table and understand how to write their symbols
SWBAT research and create a poster about a particular element
1B.6 SYMBOLS, FORMULAS, & 1B.6 SYMBOLS, FORMULAS, &
EQUATIONSEQUATIONS
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Symbols, Formulas, & EquationsSymbols, Formulas, & Equations
The international language of chemistry includes symbols, formulas, & equations.Symbols are like letters.Formulas are like words.Equations are like sentences.
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The “letters”The “letters”Symbols – Elements Symbols – Elements Elements are
organized on the Periodic Table of Elements
Each element is represented by a symbol Capital letter Capital letter &
lower case letter Find some of these
symbols on the Periodic Table.
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The Periodic Table of Elements contains much more useful information than just symbols.
You will be learning more about this table throughout this course.
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People use aluminum to make a variety of products, including foil, cans, & lightweight construction materials.
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Silicon has properties that lie between those of metals and nonmetals. It is classified as a metalloid. One of its primary uses is in electronic devices.
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Sulfur is a nonmetal used in products such as fungicides and rubber of automobile tires.
The “words”The “words”FormulasFormulas
Formulas represent specific chemical substances.
Formulas are made of symbols.
Formulas may include subscripts.
A subscript refers back to the symbol immediately before it. A “1” is “understood” & not written.
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Examples
CO 1 carbon & 1 oxygen
CO2
1 carbon & 2 oxygens NH3
1 nitrogen & 3 hydrogens H2O
2 hydrogens & 1 oxygen H2SO4
2 hydrogens, 1 sulfur, & 4 oxygens
Diatomic ElementsDiatomic Elements
Most elements exist as individual atoms and are represented with symbols.
Some elements exist as 2 bonded atoms of the same element.
For example, hydrogen is a diatomic gas, so is always written as H2 when it is an uncombined element.
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7 “GEN-U-INE DIATOMICS”
The names of all diatomic elements end in GEN or INE, and U should remember them!
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The 7 diatomic elements are all gases, but not all gases are diatomic.
Where are the 7 diatomic elements found on the Periodic Table?
The “sentences”The “sentences”EquationsEquations
Equations give the details of chemical reactions
Chemical reactions involve the breaking & making of chemical bonds, causing atoms to be rearranged into new substances.
The new substances have different properties from those of the original materials.
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The “sentences”The “sentences”EquationsEquations The original substances (reactants) are
written first. Then, an arrow points to the new substances that are made (products).
reactants productshydrogen + oxygen water
2H2 + O2 2H2O Note that this equation is “balanced.”
The total number for each kind of atom is the same for both reactants & products. 57
Do Now
During yesterday’s class, we used a metaphor in chemistry. Tell me what the following stood for and provide an example of each.
Letters= Ex. Words= Ex. Sentences= Ex.
Objectives
SWBAT define protons, neutrons, and electrons and determine the number of them in a given element.
SWBAT draw out Lewis Diagrams of different atoms
Determining Electron, Proton, and Neutron Number
Parts of the Atom Proton-
In nucleus, positive charge and a mass of 1
Neutron- In nucleus, neutral charge and a mass
of 1 Electron-
Outside nucleus, negative charge and no mass
+
-
Complete the chart
Part of Atom
Charge Mass
Proton
Neutron
Electron
So… if this is an atom…
What makes atoms different? How is carbon different from
oxygen? Different numbers of protons
Oxygen
O15.99
8
(number of protons)
(number of protons and neutrons)
(Oxygen)
Atomic
Number
Atomic MassAtomic Mass
Element
Symbol
Practice Problems
N7
9.01
4
Ne20
C12.02
Complete the missing information and include the number of protons, neutrons, and electrons.
Worksheet
Do Now
Draw out the atom, F (atomic #_____)
Objectives
SWBAT draw out Lewis Diagrams of different atoms
SWBAT identify ions as cations and anions and be able to determine the formula for ions and be able to name them.
SWBAT work in groups to answer questions as a conclusion to activity
1B.7 SYMBOLS, FORMULAS, & 1B.7 SYMBOLS, FORMULAS, &
EQUATIONSEQUATIONS
Developing Skills, p. 36 #1-3
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Lewis Dot Structure
Drawing representing the outer most (valence) electrons
EX.
Worksheet
1B.8 THE ELECTRICAL 1B.8 THE ELECTRICAL
NATURE OF MATTERNATURE OF MATTER
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Rubbing a balloon against your hair results in static electricity.
Clothes taken out of the drier often show static cling.
The shock that you sometimes receive after you walk across a rug & touch a doorknob is another example of matter’s electrical nature.
What causes these phenomena?
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Static cling is best seen when the humidity is low.
Attraction & RepulsionAttraction & Repulsion
The electrical properties of matter can be summarized as follows:
What are these positive and negative particles?
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Subatomic ParticlesSubatomic Particles
Every neutral (uncharged) atoms contains an equal number of positively charged protons (+) and negatively charged (-) electrons.# of (+) protons = # of (-) electrons
Positive-Negative attractions between the protons in one atoms the electrons in another atom hold atoms together in bonds.
Most atoms also contain neutral particles having no charge (0) called neutrons. 75
Do Now
Draw the Lewis Dot Diagrams for the following Atoms:
Ca
Li
F
Objectives
SWBAT identify cations and anions SWBAT calculate the number of
protons, neutrons, and electrons in different ions
SWBAT name and determine the formula for several ions
1B.9 IONS & IONIC 1B.9 IONS & IONIC
COMPOUNDSCOMPOUNDS
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Ions and Ionic CompoundsIons and Ionic Compounds
Recall: Molecules make up one kind of compound.
Ions make up another kind of compound.
Ions are electrically charged atoms (or groups of atoms).
Ions are formed when neutral atoms gain or lose electrons.
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IonsIons
Ions are electrically charged atoms (or groups of atoms).
Ions are formed when neutral atoms gain or lose electrons.
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IonsIons
Recall: What charge do electrons carry?Negative
When atoms gain negative electrons, they form negative ions.
When atoms lose negative electrons, they form positive ions.
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IonsIons
For example, sodium (Na) is # 11 on the Periodic Table.
It has 11 (+) protons and 11 (-) electrons. If it lost 1 (-) electron, it would have 11 (+)
protons and 10 (-) electrons. It has one more proton than electrons, so it
has a charge of -1. The symbol for a sodium ion is Na1+ or just
Na+. (The 1 is understood.)
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IonsIons
For another example, chlorine (Cl) is # 17 on the Periodic Table.
It has 17 (+) protons and 17 (-) electrons. If it gained 1 (-) electron, it would have 17
(+) protons and 18 (-) electrons. It has one less proton than electrons, so it
has a charge of +1. The symbol for a chloride ion is Cl1- or just
Cl-. (The 1 is understood.)
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Do Now
List the number of protons, electrons, and neutrons in each ion O2-
H+
F3-
Do any of these atoms have complete valence shells?
Objectives
SWBAT determine the formulas for ionic compounds
SWBAT name different ionic compounds
Ionic CompoundsIonic Compounds
Oppositely charged ions connect together to form ionic compounds.
For example, sodium ions (Na+) connect to chloride ions (Cl-) to make sodium chloride (NaCl), or table salt.
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Sodium chloride consists of an equal number of positive and negative ions arranged in a 3-dimensional network called a crystal.
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A scanning electron micrograph shows the cubic structure of NaCl crystals.
A space-filling model of NaCl provides information about how the individual sodium ions & chloride ions are arranged within the salt crystal.
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What else does this model suggest about the sodium and chloride ions or sodium chloride?
If an ionic compound dissolves in water, the individual ions would separate from each other and spread out throughout the water.
To show that they were now in an aqueous solution, an (aq) would be added after the symbols for the ions.
Na+(aq) Cl- (aq)
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More about IonsMore about Ions
Cation – positive ion
Anion – negative ion
Monoatomic ions (or monatomic)
Polyatomic ions
Na+, Cl-, Mg2+, O2-, Al3+, N3-
NH4+, CO3
2-, SO42-,
PO43-
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Common IonsCommon Ions
See text p. 40 for a list of common ions.
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Formulas for Ionic CompoundsFormulas for Ionic Compounds
2 Rules for Writing Formulas for Ionic Compounds
1. Cation first, then anion
2. Correct formula will be neutral, with the fewest number of each ion needed to make the total electrical charge zero
No charges are shown in the formula.
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Practice Problems
NaCl One Na1+ and one Cl1- cancel each other out.
+1 + -1 = 0
CaCl2
One Ca2+ needs two of the Cl1- to cancel it out. +2 + -1 + -1 = 0
Note: Negative monoatomic ions change their ending to “ide.”Examples above are sodium chloride and calcium chloride.
Formulas Containing Formulas Containing Polyatomic IonsPolyatomic Ions
Formulas for compounds containing polyatomic ions follow the same rules
If a subscript is needed, it follows the entire polyatomic ion, which is enclosed in parentheses
For example, the calcium ion has a +2 charge, and the nitrate ion has a -1 charge
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Formulas Containing Formulas Containing Polyatomic IonsPolyatomic Ions
For example, the calcium ion has a +2 charge (Ca2+), and the nitrate ion has a -1 charge (NO3
1+). Two nitrate ions are needed to balance
out the charge on one calcium ion. The formula for calcium nitrate is:
Ca(NO3)2. No charges are shown in the formula.
Polyatomic ions do not change their endings.
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Naming Ionic Compounds
1. Name the cation, then the anion 2. Have the last few letters changed
to –ide (monoatomic ions only)
Ex. KF, potassium fluoride
Ex. Ca(NO3)2, calcium nitrate
Do Now
Write the formula and name the following ionic compounds
1. Ca2+ Br-
2. PO43- Ag+
3. CO32- NH4
+
4. Al3+ NO3-
What does the word “ionic” mean?
Objectives
SWBAT determine the formulas for several polyatomic and monoatomic compounds
SWBAT explain what a mole is and present their projects
SWBAT read fun facts about the mole
1B.10 IONIC COMPOUNDS1B.10 IONIC COMPOUNDS
Developing Skills, p. 41
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IB.11 WATER TESTINGIB.11 WATER TESTING
Investigating Matter, pp. 42-45
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Do Now
Explain what charge the following items typically carry and WHY!
Lithium Chlorine Calcium
Figuring out Charges
Do Now
1. Draw the Lewis Dot diagram for Li+.
2. Draw a picture of a heterogeneous mixture of elements X and B.
Objectives
1. SWBAT start to review for the test by going over the answers review questions.
2. SWBAT read and think critically about the Riverwood Fish Kill.
3. SWBAT create 2 possible hypothesis about the Riverwood fish kill.
Take out questions:
Pg. 51 #15-24
1B.12 PURE AND IMPURE 1B.12 PURE AND IMPURE
WATERWATER
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Pure vs. Clean WaterPure vs. Clean Water
In the U.S., we all have access to abundant, low cost, clean, but not pure water
Even if the cost was not prohibitive, it would be impossible to have 100% pure water.
Atmospheric gases (e.g., O2, N2, CO2) will always dissolve in the water to some extent.
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IB.13 THE RIVERWOOD IB.13 THE RIVERWOOD
WATER MYSTERYWATER MYSTERY
Making Decisions, p. 46
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1B.14 WHAT ARE THE 1B.14 WHAT ARE THE
POSSIBILITIES?POSSIBILITIES?
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HOW DO YOU NARROW DOWN HOW DO YOU NARROW DOWN THE DATA TO GET THE THE DATA TO GET THE ANSWER?ANSWER?
The cause of the fish kill may be related to something suspended in or dissolved in the water. What might it be?
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Chemistry at WorkChemistry at Work
To learn about careers that require knowledge about what you are learning about in class right now, read text pp. 48-49, Environmental Cleanup: It’s a Dirty Job… But That’s the Point
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