Chemistry is Hard

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Chemistry is Hard

• Why?

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Blooms Taxonomy

• Psychologist who studied how people think Broke
  thinking into levels of complexity
• The lowest level is knowledge- memorizing
  textbook definitions
• Easiest but least useful

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Blooms Taxonomy

• Understanding- being able to put the knowledge
  into you own words
• Application- being able to use the information in
  new situations
• Analysis- breaking the information into
  meaningful pieces
• Synthesis- being able to put information together
  to generate new learning
• Evaluation- using all the information, making and
  defending value judgments about the information.

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Evaluation
Synthesis
Analysis
Application
Understanding
Knowledge
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What does this have to do with chemistry?

• In the past, many of your classes relied on
  memorization.
• Chemistry focuses on the higher levels.
• Chemistry asks you to learn processes and
  techniques and then apply them to novel situations

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Evaluation
Synthesis
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Analysis
Application
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Understanding
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Knowledge
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Word Clues How hard do I have to think?

• Knowledge
• Who, what, where, when, tell, label, define,
  select, choose, identify, describe, recall
• Comprehension
• Show, explain, discuss, classify, recognize,
  summarize, paraphrase

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Word Clues

• Application
• Use, solve, teach, relate, explain, predict,
  compute, illustrate, simulate, demonstrate
• Analysis
• Probe, dissect, outline, compare, organize,
  diagram, distinguish, investigate, categorize

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Word Clues

• Synthesis
• Plan, make, invent, develop, design, propose,
  predict, assemble, formulate, hypothesize
• Evaluation
• Rate, judge, revise, critique, defend, justify,
  assess, contrast, support, recommend, conclude,
  interpret

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Chapter 1

• Chemistry is a Physical Science

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What is Chemistry?

• The study of the matter, its composition,
  properties, and the changes it undergoes.
• Pure chemistry gathers knowledge for knowledges
  sake
• Applied chemistry is the using chemistry to
  attain certain goals, in fields like medicine,
  agriculture, and manufacturing

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Branches of Chemistry

• Analytical Chemistry -studies composition of
  substances.
• Organic Chemistry -compounds containing carbon
• Inorganic Chemistry -substances without carbon
• Biochemistry- Chemistry of living things
• Physical Chemistry studies behavior of substances
• rates and mechanisms of reactions
• energy transfers

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1. Organic Chemistry

• Organic is the study of matter that contains
  ______
• Organic chemists study the structure, function,
  synthesis, and identity of carbon compounds
• Useful in petroleum industry, pharmaceuticals,
  polymers

Carbon
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2. Inorganic Chemistry

• Inorganic is the study of matter that does NOT
  contain ________
• study the structure, function, synthesis, and
  identity of non-carbon compounds
• Polymers, Metallurgy

Carbon
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3. Biochemistry

• Biochemistry is the study of chemistry in ______
  things
• Cross between biology and chemistry
• Pharmaceuticals and genetics

Living
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4. Physical Chemistry
HONK if you passed Chemistry

• the physics of chemistry the forces of matter
• computational
• Develop theoretical ideas for new compounds

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5. Analytical Chemistry

• Analytical chemistry is the study of high
  precision measurement
• Find composition and identity of chemicals
• Forensics, quality control, medical tests

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Why study Chemistry?

• Explain the natural world
• Why?
• Prepare for a career
• Directly- in a lab
• Indirectly- problem solving and thinking skills
• Be an informed citizen
• Vote
• Dont get scammed

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Scientific Method

• A way of solving problems or answering questions.
• Starts with observation- noting an recording
  facts
• Hypothesis- a possible explanation as to the
  cause of the observation, based on research and
  previous knowledge

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Scientific Method

• Experiment- designed to test the hypothesis
• only two possible answers
• hypothesis is right
• hypothesis is wrong
• Generates data -observations from experiments.
• Modify hypothesis - repeat the cycle

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Variables

• Controlled experiment- Only want one thing to
  change at a time in a laboratory.
• Manipulated variable- What you change or control
  directly
• Also called independent variable
• Responding variable What changes as a result.
  No direct control
• Also called dependent variable

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Scientific Theory

• Cycle repeats many times by you and by others
• A thoroughly tested model that explains why
  things behave a certain way.

Observations
Hypothesis
Experiment
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Scientific Theory

• Theory can never be proven.
• Predicts behavior
• Help us form mental pictures of processes (models)

Observations
Hypothesis
Experiment
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Scientific Law

• Another outcome is that certain behavior is
  repeated many times
• Description of how things behave
• Usually an equation
• Law - how
• Theory- why

Observations
Hypothesis
Experiment
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Observations
Hypothesis
Experiment
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Chapter 1

• Matter and Its Properties

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What is Matter?

• Matter is anything that takes up space and has
  mass.
• Mass is the amount of matter in an object.
• Mass is resistance to change in motion along a
  smooth and level surface.

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Two Properties of Matter

• Mass
• Weight

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Types of Matter

• Substance- a particular kind of matter - pure
• Mixture- more than one kind of matter

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Properties

• Words that describe matter (adjectives)
• Physical Properties- a property that can be
  observed and measured without changing the
  substance.
• Examples?
• Chemical Properties- a property that can only be
  observed by changing the type of substance.
• Examples?
• Used to identify a substance

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States of matter

• Solid- mater that can not flow and has definite
  volume.
• Liquid- definite volume but takes the shape of
  its container (flows).
• Gas- a substance without definite volume or shape
  and can flow.
• Vapor- a substance that is currently a gas but
  normally is a liquid or solid at room temperature.

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States of Matter
Definite Volume?
Definite Shape?
Temp. increase
Com-pressible?
Small Expans.
Solid
YES
YES
NO
Small Expans.
Liquid
NO
NO
YES
Large Expans.
Gas
NO
NO
YES
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Liquid
Gas
Solid
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Physical Changes

• A change that changes appearances, without
  changing the composition.
• Examples?
• Chemical changes - a change where a new form of
  matter is formed.
• Also called chemical reaction.
• Examples?
• Not phase changes
• Ice is still water.

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Indications of a chemical reaction

• Energy absorbed or released
• Color change
• Odor change
• Precipitate- solid that separates from solution
• Not easily reversed

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Chemical Reactions

• When one or more substances are changed into new
  substances.
• Reactants- stuff you start with
• Products- What you make
• NEW PROPERTIES
• Not easily reversed

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Conservation of Mass

• Mass can not be created or destroyed in ordinary
  (not nuclear) changes.
• All the mass can be accounted for.

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Mixtures

• Made up of two substances.
• Variable composition?
• Heterogeneous- mixture is not the same from place
  to place.
• Chocolate chip cookie, gravel, soil.
• Homogeneous- same composition throughout.
• Kool-aid, air.
• Every part keeps its properties.

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Energy

• The ability to do work.
• Work - cause a change or move an object.
• Many types- all can be changed into the other.

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Types of energy

• Potential- stored energy
• Kinetic Energy- energy something has because its
  moving
• Heat- the energy that moves because of a
  temperature difference.
• Chemical energy- energy released or absorbed in a
  chemical change.
• Electrical energy - energy of moving charges

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Types of Energy

• Radiant Energy- energy that can travel through
  empty space (light, UV, infrared, radio)
• Nuclear Energy Energy from changing the nucleus
  of atoms
• All types of energy can be converted into others.
• If you trace the source far enough back, you will
  end up at nuclear energy.

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Conservation of Energy

• Energy can be neither created or destroyed in
  ordinary changes (not nuclear), it can only
  change form.
• Its not just a good idea, its the law.

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What about nuclear?

• E mc2
• energy mass x (speed of light)2
• speed of light 3 x 108
• A little mass can make a lot of energy
• Law of Conservation of Mass - Energy the total of
  the mass and energy remains the same in any change

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Substances

• Elements- simplest kind of matter
• Cannot be broken down into simpler
• All one kind of atom.
• Compounds are substances that can be broken down
  by chemical methods
• When they are broken down, the pieces have
  completely different properties than the
  compound.
• Made of molecules- two or more atoms stuck
  together

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Compound or Mixture
Compound
Mixture
One kind of piece- Molecules
More than one kind - Molecule or atoms
Making is a chemical change
Making is a physical change
Only one kind
Variable composition
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Which is it?
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Solutions

• Homogeneous mixture
• Mixed molecule by molecule
• Can occur between any state of matter.
• Solid in liquid- Kool-aid
• Liquid in liquid- antifreeze
• Gas in gas- air
• Solid in solid - brass
• Liquid in gas- water vapor

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Solutions

• Like all mixtures, they keep the properties of
  the components.
• Can be separated by physical means
• Not easily separated- can be separated without
  creating anything new.

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Chemical symbols

• There are 109 elements
• Each has a 1 or two letter symbol
• First letter always capitalized second never
• Dont need to memorize
• Some from Latin or other languages