Transcript Introduction to Chemistry and Measurement

Scientific Method
Technology
Observation
Applied
Chemistry
1. Inorganic Chemistry
• Inorganic is the
study of matter that
does NOT contain
Carbon
________
• Inorganic chemists
study the structure,
function, synthesis,
and identity of noncarbon compounds
• Polymers,
Metallurgy
2. Organic Chemistry
• Organic is the study of
carbon
matter that contains ______
• Organic chemists study the
structure, function,
synthesis, and identity of
carbon compounds
• Useful in petroleum
industry, pharmaceuticals,
polymers
3. Physical Chemistry
• Physical
chemistry is the
physics of
chemistry… the
forces of matter
• Rates and energy
transfers
• Much of p-chem
is computational
4. Analytical Chemistry
• Analytical chemistry
is the study of high
precision
measurement
• Find composition
and identity of
chemicals
• Lead in drinking H2O
• Forensics, quality
control, medical
tests
5. Biochemistry
• Biochemistry is
the study of
chemistry in
living things
______
• Cross between
biology and
chemistry
• Pharmaceuticals
and genetics
Properties of Matter
Extensive properties depend on the amount
of matter that is present.
Volume
Mass
Energy Content (think Calories!)
Intensive properties do not depend on the
amount of matter present, but type of
matter. Melting point, Boiling point
Color
Density
Hardness
Law of conservation of mass
• In all physical and chemical
changes, the mass of the
reactants MUST equal the mass of
the products.
Scientific Method
1. State the problem clearly./Make Observ.
2. Formulate a hypothesis
3. Test the hypothesis.
4. Evaluate the data to form a conclusion.
If the conclusion is valid, then it
becomes a theory. If the theory is
found to be true over along period of
time (usually 20+ years) with no
counter examples, it may be
considered a law.
5. Share the results.
Chapter 2
Chemistry is the study of matter and the
changes it undergoes
1. Matter is anything that occupies space and
has mass. “stuff”
2. A substance is a form of matter that has a
definite composition and distinct properties.
water, ammonia, sucrose, gold, oxygen
Phase
Differences
Solid – definite volume and shape; particles packed
in fixed positions.
Liquid – definite volume but indefinite shape; particles
close together but not in fixed positions
Gas – neither definite volume nor definite shape;
particles are at great distances from one another
Plasma – high temperature, ionized phase of matter
as found on the sun.
Physical
Properties
What are some physical
properties?
• color
• melting and boiling
point
• odor
• Create a definition for
“physical properties”
Physical Changes
–can be observed
without changing the
identity of the
substance
Physical change Ex.
• boiling of a liquid
• melting of a solid
• dissolving a solid in a
liquid to give a
homogeneous mixture
• — a SOLUTION.
A mixture is a combination of two or more substances
in which the substances retain their distinct identities.
1. Homogenous mixture – composition of the
mixture is the same throughout.
soft drink, milk, salt water
2. Heterogeneous mixture – composition is not
uniform throughout.
Rocky Road Ice Cream, soil, pizza
chicken noodle soup
Types of Mixtures
Heterogeneous –
visibly separate phases
Homogeneous –
Same throughout
Physical means can be used to separate a mixture
into its pure components.
magnet
distillation
Filtration
Separation of a Mixture
Distillation
Separation of a Mixture
The components of
dyes such as ink
may be separated
by paper
chromatography.
An element is a substance that cannot be
separated into simpler substances by chemical
means.
• “116” elements have been identified
• 82 elements occur naturally on Earth
gold, aluminum, lead, oxygen, carbon
• 34 elements have been created by
scientists
technetium, americium, seaborgium
A compound is a substance composed of atoms
of two or more elements chemically united in fixed
proportions.
Compounds can only be separated into their
pure components (elements) by chemical
means.
Water (H2O)
Glucose (C6H12O6)
Ammonia (NH3)
Separation of a Compound
The Electrolysis of water
Compounds must be
separated by chemical
means.
With the application of
electricity, water can
be separated into its
elements
Reactant

Water

H2O

Products
Hydrogen + Oxygen
H2
+
O2
Matter Flowchart
Fill in the flow chart AND provide
and example for each box.
Matter
yes
Can it be physically
separated?
Mixture
yes
Is the composition
uniform?
Homogenous
no
Pure substance
no
Heterogenous
yes
Can it be chemically
decomposed?
Compound
no
Element
Organization of Matter
Matter
Mixtures:
a) Homogeneous (Solutions)
b) Heterogeneous
Pure Substances
Elements
Compounds
Atoms
Nucleus
Electrons
Protons
Neutrons
Quarks
Quarks
Physical vs. Chemical
Properties
• Examples:
– melting point
physical
– flammable
chemical
– density
physical
– magnetic
physical
– tarnishes in air
chemical
Physical vs. Chemical
Changes
•
Examples:
– rusting iron
Chemical
– dissolving in water
Physical
– burning a log
Chemical
– melting ice
Physical
– grinding spices
Physical
Sure Signs of a Chemical
Change
• Change in Temp
• Light
• Gas Produced (not from
boiling!)
• Precipitate – a solid
formed by mixing two
liquids together
• Color Change???
Use it or not?
• Pure Chemistry – pursuit of
chemical knowledge for its own
sake.
• Applied Chemistry – research that is
directed toward a practical goal or
application.