The%20Science%20of%20Chemistry

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The Science of Chemistry

• Ch.1

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(1-1) Chemicals

• Any substance w/ a definite composition

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Physical States of Matter

• Solids fixed V shape
• Liquids fixed V, variable shape
• Gases neither fixed V nor fixed shape

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Chemical Rxns

• Elements /or cmpds interact to form new
  substances
• Reactants starting materials
• Products ending materials
• Reactant reactant ? products
• Activation E needed to start rxn

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Rxns

• Exothermic releases E
• Ex feels hot
• Burning fossil fuels
• Endothermic absorbs E
• Ex feels cold
• Photosynthesis

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(1-2) Matter

• Anything that has mass V
• Volume space an object occupies
• 1 mL 1 cm3
• Mass vs. weight
• Wt. is based on gravity,
• mass is not

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Measurement

• Qualitative not numerical
• Ex color, small/large, heavy/light
• Quantitative numerical
• Ex 47 g, 102 lbs

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SI Base Units

• Length meter (m)
• Mass kilogram (kg)
• Time second (s)
• Temp. kelvin (K)
• Amount of substance mole (mol)
• Derived Units
• Area, volume, etc.

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SI Prefixes

• Giga
• Mega
• Kilo
• Hecto
• Deka

• Deci
• Centi
• Milli
• Micro
• Nano
• Pico
• Femto

Table 1-4. p.13
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Conversion Factor

• Relates 2 units
• 1 kg 1000 g or 1 g 0.001 kg
• Ex 1.5 kg x 1000 g 1500 g
• 1 kg
• Always write units!!!!
• http//facweb.eths.k12.il.us/weinerj/PPT_Presentat
  ions/introdustion_to_conversions.ppt

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Density

• Density mass or D m
• volume V
• Units g/cm3 or g/mL
• Identify substances

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Density Practice

• Silvers density is 10.5 g/cm3. You have a
  bracelet w/ a mass of 199 g a volume of 20.5
  cm3. Is the bracelet pure silver?
• D m 199 g 9.71 g/cm3
• V 20.5 cm3

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Physical Property

• Measured w/out changing its chemical nature
• Physical change affects only physical
  properties
• Ex melt ice, boil water

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Chemical Properties

• Observed only when substances interact
• Chemical change produces new substances
• Ex rust
• Change in E (exo or endo)

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Chemical Change Evidence

• Evolution of a gas (smell/bubbles)
• Formation of a precipitate (ppt)
• Evolution or absorption of heat
• Emission of light
• Color change

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Property Practice

• The boiling pt of ethyl alcohol is 78ºC
• P describes inherent property
• Diamond is very hard
• P describes inherent property
• Sugar ferments to form ethyl alcohol
• C describes behavior of sugar forming a new
  substance

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(1-3) Nature of Matter

• Atom basic unit of matter
• Element simple substances that combine to make
  complex substances
• Periodic Table

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Molecules

• Neutral group of atoms held together by covalent
  bonds
• Monatomic 1 type of atom
• Noble gases
• Diatomic 2 of the same type of atom bonded
  together
• BrINClHOF

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Allotrope

• Different forms of an element
• Oxygen has 2
• O2 oxygen gas
• O3 ozone (toxic)

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(1-4) Classifying Matter

• Compound product of elements chemically
  combining
• Covalent (sugar) vs. ionic (salt)
• Ion atom or group of atoms w/ a charge

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Acids Bases

• Tastes sour
• pH lt 7
• Turns litmus red

• Tastes bitter
• Feels slippery
• pH gt 7
• Turns litmus blue

• React w/ each other to form salts
• pH scale used to express acidity (1-14)

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Classifying Compounds

• Organic covalently bonded carbon-containing
  cmpd
• Few exceptions (carbonates oxides)
• Inorganic not organic
• All w/out C, H, O

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Formulas

• Molecular shows s of atoms
• Aspirin C9H8O4
• Structural of atoms how bonded

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Formulas

• Ball Stick geometric arrangement
• Space-fill closest to actual shape of molecule

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Mixtures

• Collection of 2 or more pure substances
  physically mixed together
• Homogenous (solutions) uniformly distributed
• Gas, air, tea
• Heterogeneous not uniform
• Soil, salad, chocolate chip cookie

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Mixture Practice

• Gasoline
• Homogenous
• A stream with gravel on the bottom
• Heterogeneous
• Copper metal
• Pure substance