u2d2: classification of matter do now: 1.look over new packets. write your name on all papers....
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U2D2: Classification of MatterDo Now: 1. Look over new packets. Write your name on all papers.2. Draw a sample of a mixture of an element and a
compound.Today: 3. Book Hand out (shout out book # when asked)4. Review POGIL/Do NOW/Check3. Classification of Matter: focus on Mixtures
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U2D1:MATTER!!!• Chemistry is all about the
study of matter, the changes it undergoes and the energy associated with these changes.
• Matter is simply anything that has a definite mass and volume.
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Hmm….
• Is there anything in this room that would be considered matter?
MATTER
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Substances
• Are types of pure (homogeneous) matter– containing the same composition of material
throughout the sample• Cant distinguish different parts• Which is a substance?
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A. Pure Substances: Have a fixed composition: H2O is ALWAYS 2-H and 1-O
1. Elements: cannot be decomposed by chemical change.• They are made up of 1 type of atom• All atoms have the same element have the same
atomic # (# of protons)• Symbols
– 1 capital letter : O, N, C– 2 letters, the first of which is capitalized, the second
lower-case: Ni, Fe, Li, Xe.
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A. Pure Substances:
1. Elements:
Diatomic: _______________________
Monatomic: ______________________
Particle Pictures of Elements single Atom, Diatomic
ex. Fe or Rn Molecule, O2
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2. Compound: 2 or more different elements chemically combined
• CAN be DECOMPOSED into separate elements. (by chemical means)– 2 H2O 2 H2 + O2
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EXAMPLES OF COMPOUNDS Calcium Chloride: CaCl2
Sodium Chloride: NaClWater: H2O
Glucose: C6H12O6
Sucrose (table sugar): C12H22O11
Methane: CH4
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COMPOSITION OF COMPOUNDS • 2 or more DIFFERENT elements chemically
combined• Homogeneous- same throughout• Have a definite ratio
CaCl2 NaCl CH4 KNO2 1 : 2 1:1 1 : 4 1:1:2
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Compounds• Have properties DIFFERENT from the elements
which make them up• Na: an explosive silver colored metal• Cl2: poisonous yellow-green gas
– NaCl: tasty, white colored condiment on French fries
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Na: an explosive silver colored metal
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Cl2: poisonous yellow-green gas
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But Chemically combined in a Compound …
• NaCl: tasty, white colored condiment on French fries
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Whats my rule
• K• Al• Kr
• SrS• MnO2
• HCN
What about: Na2SO4, Mn
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Phases of a Pure Substances
Indicated by subscripted letter:• NaCl (s) –> (s) = ____________
• H2O (l) –> (l) = ____________
• CH4 (g) --> (g) = ____________
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MATTER
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MixturesB. Mixtures: combinations of substances that ARE NOT chemically combined togetherVariable (changeable) composition:
– a little sugar in a glass of water OR a lot of sugar in a glass of water
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Mixtures
Substances retain (keep) their characteristics or properties so when you separate them, you get the same substances back
Ex. _____________________________________
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Mixtures
Mixtures of the same substances may have different properties if the amount of each is different in the mixtures:
• Cast Iron: brittle (iron with a lot of carbon)(Cast iron pans, railings)
• Steel: Bendable – malleable (iron with a little carbon)
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A. Homogeneous Mixture- components are
uniformly distributed throughout
a. Characteristics:– Uniform – the same
throughout– Cannot see parts – Can not be separated by
filtration (but can be boiled to separate)
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b. Partssolute – ______________________________
ex:____________
solvent - ______________________________ ex. ____________
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Other Homogeneous Mixtures
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c. Types of Homogeneous Mixtures
1. Amalgam: mercury (Hg) is the solvent:
Ex. silver dental fillings: silver (Ag) dissolved in Hg
(Also used to mine gold (Au), bad for the environment)
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c. Types of Homogeneous Mixtures
2. Tincture: ethanol (alcohol) is the solvent: • tincture of iodine (I2)
• I2 dissolved in alcohol
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Other Homogeneous Mixtures
3. Alloy: 2 or more metals mixed togetherex. copper and zinc: ______________ ex. copper and tin: _______________ any gold (Au) less than 24K:
14K: 14 parts Au and 10 parts other metal18K: _____ parts Au and ______ parts other metal
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4. AQUEOUS solutions Homogeneous mixtures with water as the solvent _______________ solutions NaCl (aq) (aq)= aqueous
Sodium chloride dissolved in water
Solution means a homogeneous mixture
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Aqueous Solutions: ex. NaCl (aq)
Recall…..• solute – stuff that gets dissolved __________• solvent - stuff that does the dissolving ____________
• Water is called the ____________ ___________ because it dissolves so many things well
**SOLUTION MEANS HOMOGENEOUS MIXTURE****
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2. Heterogeneous Mixtures :varying composition throughout
a. Characteristics• Particles are visible• Large particles will settle out; needs to be shaken
in water mixtures • Can be separated by filtration (water
suspensions)
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Heterogeneous Mixtures (also called a suspension)
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b. Examples:
Sand & WaterGranite
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Heterogeneous Mixtures
Oil & Water Pizza
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Colloids
• Special type of heterogeneous mixture- Particles are larger than molecules but too small to see
• Scatter light so makes things blurry, turbid (cloudy), translucent
Fog
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Colloids
• Cloudy aquarium • Whipped Cream• Mayonaise
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Mixture Dot Diagram
• See how we have 2 different things mixed together
• Red and blue are bound together (compound) and yellow (element) is mixed with it
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Practice!
MIXTURE HOMOGENEOUS HETEROGENEOUS Soil Air (clean) KCl (aq) 22 K Gold
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Identify the following as HOMOGENEOUS or HETEROGENEOUS mixtures by placing a check () underneath the appropriate
heading.
MIXTURE HOMOGENEOUS HETEROGENEOUS Chocolate Chip Cookie NaNO3 (aq) Italian Salad Dressing Sand & water
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Work on Practice 2.1
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Physical vs Chemical propertiesLet’s Brainstorm your own Chemical and Physical properties and changes
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Properties of Elements
• Properties do not vary: All samples of aluminum have the same density
• Cannot change identity or properties by PHYSICAL changes ex. Boiling, melting
• Can change in identity and properties by a CHEMICAL change ex. Burning (combustion), rusting (oxidizing)
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Reference Table S: (Superfriends’ favorite): properties of the elements
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Substances; Elements
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U2D2: Properties of Mixtures; Using a Bunsen burner
Agenda:HW Collected: Vocab diagrams and 5 Q’sLab Check :need calculator and ref TableComplete Properties of MixturesHow to use the Bunsen burner!
Date Assignment Grade page
9/24 Density of Al Foil Check 249/24 How to Use a Bunsen Burner 25
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Changes of Matter
• They can either be physical or chemical• Physical: Doesn’t Change the Identity of the
matter, just its form• Chemical: changes the identity of the matter
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You tell me; Physical or Chemical?
• The paint has worn away, so the steel body of an old car begins to rust (rust forms when iron reacts with oxygen…)– Chemical
• Potassium thiocyanate crystals dissolve easily into water.– Phyiscal
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You tell me; Physical or Chemical?
• A 10.0 g sample of lauric acid can be melted by adding heat.– Physical
• Sodium metal explosively reacts with water to form hydrogen gas and sodium hydroxide.– Chemical
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Physical Changes: ID stays the same
• Melting• Boiling• Dissolving• Evaporating• Crushing• Stretching• Changing its shape
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Chemical changes: ID changes
• Rusting (Iron reacting with oxygen)• Burning (Reacting with Oxygen)• Decomposing (Breaking bonds)
– 2 H2O 2 H2 + O2
• Reacting with…• X + Y XY A new compound was made!
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Chemical Change
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Mixtures: Homogenous
• Remember, homogeneous means that it is uniform throughout the mixture.– Cant distinguish one part from
another.
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Illustrating Types of Matter; Dot Diagrams
• Each dot represents a single atom. • Different types of dots are different types of
elements• Ex; Different phases of the same element:
Solid Liquid Gas
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What are these dot diagrams for?Element
Diatomic Molecule (not a compound since its only 1 type of atom). Br, I, N, Cl, H, O, F
Compound (2 different elements bonded together)
Heterogeneous Mixture
Homogeneous Mixture
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Whats my rule?
• Sugar (C6H12O6)
• CuSO4
• Water
• Iron• Hydrogren• Helium
• What about: FeO, Mercury
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Figure out what makes the 2 columns different and then classify the bottom terms
• Water• Iron• Sugar
• Gatorade• Sugar Water• Salad
• What about; Aluminum, cereal, coffee, oxygen
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Whats my rule?
• Mud• Garbage• Chocolate chip
cookie dough
• Salt water• Kool-aid• Tap water
• What about: Iced Tea, a bag of skittles
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Rest of the period:
Continue the guided practice.
Homework for tonight:• Finish HW # 1