Introduction to Chemistry

1
Introduction to Chemistry

• What Matters?

2
SI Units

• Length meter
• Mass kilogram
• Time second
• Temperature Kelvin
• Quantity of Matter mole
• Volume - liter

3
Commonly Used Prefixes

• Centi- 1/100 or 0.01
• Kilo- 1000 or 1.0 x 103
• Milli- 1/1000 or 0.001

4
Matter

• Def- anything that has mass and occupies space
• 3 States of matter
• Solid
• Liquid
• Gas

5
Phase Changes

• Melting
• Freezing
• Vaporization/Evaporation
• Condensing
• Sublimation
• Deposition

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Changes of State
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Melting/Freezing

• Energy must be ADDED for a substance to melt
• Energy must be REMOVED for a substance to freeze

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Vaporization Condensation

• Energy must be ADDED for a substance to boil
• Energy must be REMOVED for a substance to condense

9
Deposition/Sublimation

• Energy must be added for a substance to sublime
• Energy must be removed for a substance to undergo
  deposition

10
Law of Conservation of Energy

• Energy cannot be created or destroyed
• Energy of a reaction MUST be conserved

11
Elements, Compounds Mixtures
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Elements

• An element is matter in its simplest form
• Cannot be broken down by chemical means
• Periodic Table (114 elements)

13
Compounds

• Are combinations of elements
• Have the same composition
• Can be broken down by chemical means

14
Mixtures

• Have variable composition
• Can be separated physically or chemically
• Homogeneous Mixtures are the same throughout
• Heterogeneous Mixtures have different regions

15
Law of Conservation of Matter

• Matter cannot be created or destroyed
• Mass of a chemical reaction MUST be conserved

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Separatory Techniques
17
Filtration

• Used for separating undissolved solids
• Pour through a mesh (filter paper)

18
Distillation

• Used to separate dissolved solids or liquid
  mixtures
• Uses physical changes

19
Chromatography

• Uses chemicals to separate the pigments of plant
  or chemicals
• Various Methods
• Gas chromatography
• Liquid chromatography
• Thin-layer chromatography
• Ion-exchange chromatography

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Chemical vs Physical
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Physical Properties

• A set of characteristics unique to a substance

• Odor
• Color
• Volume
• State
• Density
• Boiling point
• Melting point

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Chemical Properties

• The ability of a substance to form new substances

• Wood burning
• Iron rusting
• Digestion
• photosynthesis

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Physical Change

• Does NOT change the identity of the substance
• Composition remains the same

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Chemical Change

• Changes the composition of the substance
• Has new physical properties that differ from the
  original

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Indicators of Chemical Change

• Formation of a gas (bubbles)
• Formation of a precipitate (solid)
• Change in temperature
• Exothermic
• Endothermic
• Color change

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Properties

• Extensive Properties depend on the amount of
  substance present
• Volume
• Mass
• Energy present
• Intensive Properties do NOT depend on the
  amount of substance present
• Melting point
• Boiling point
• Density
• Conductivity

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Solids, Liquids, and Gases

• Solids have both definite volume and shape
• Liquids have definite volume but not shape
• Gases have neither definite volume or shape
• Particles have increasing velocity from solids to
  liquids to gases

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Elements The Periodic Table

• Periods horizontal rows
• Groups vertical columns
• Group 1A alkalai metals
• Group 2A alkalai earth metals
• Group 3A-12A transition metals
• Group 16A chalcogens
• Group 17A halogens
• Group 18A noble gases

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The Periodic Table
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Metals

• Conduct heat and electricity
• Malleable
• Ductile
• Luster (shiny)

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Non-metals

• Poor conductors of heat
• Poor conductors of electricity
• Many are gases at room temp
• 5 solid non-metals
• Phosphorous
• Sulfur
• Carbon
• Selenium
• iodine

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Metalloids

• Have some characteristics of both metals and
  non-metals

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Noble Gases

• Least reactive of all elements
• All gases at room temp