Transcript Matter - Neshaminy School District

Matter
Property and Changes
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____ Properties of Matter
____ Changes in Matter
____ Classification of Matter
Mixtures
Compounds and Elements
____ Law of Conservation of Mass
____ Law of Definite Proportions
____ Law of Multiple Proportions
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Define the bold face words.
Be sure you know table 3-17 on page 71.
Read Section 3-1 Properties of Matter Take notes on the following terms:
substance, solids, liquids, gases, physical properties, chemical properties,
intensive properties, and extensive properties. Know the Law of
Conservation of Mass. It is a good idea to leave space between each
concept so that you can add any additional information in class.
Read Section 3-2 – Read this and takes notes on the following ideas:
physical and chemical changes and the signs of a chemical reaction (fig3-8
and 3-9)
Read Section 3-3. Read this and take notes on the following ideas:
mixtures, heterogeneous, homogeneous. Separating mixtures. Having
definitions and examples would be good. How are compounds different
from mixtures?
Read Section 3-4 Elements and compounds. Know the difference between
a compound and a mixture. Become familiar with the Periodic Table of the
Elements. Know The Law of Definite Proportions.
• Substance – matter that has a uniform and
unchanging composition.
• Also known as a pure substance
• E.g. Table Salt NaCl, Water H2O;
Physical Property
• A physical property is observed with the
senses and can be determined without
destroying the object. For example, color,
shape, mass, length, and odor are all
examples of physical properties
chemical property
• A chemical property indicates how a
substance reacts with something else.
The original substance is fundamentally
changed in observing a chemical property.
For example, the ability of iron to rust is a
chemical property. The iron has reacted
with oxygen, and the original iron metal is
changed. It now exists as iron oxide, a
completely different substance.
• Intensive properties do
not depend on the
amount of substance (for
example, alcohol is
flammable, also density,
hardness, temperature).
• What about color?
• Extensive properties do depend on the
amount (for example, the mass of the
alcohol, volume, and length).
• What about the number of atoms in a
substance?
http://www.youtube.com/watch?
v=C4pQQQNwy30
Phases of Matter
• Solid- Liquid- Gas- Plasma-BEC
Phases of Matter
• Solid- Liquid- Gas- Plasma-BEC
Phases of Matter
• Solid- form of matter that has a definite
shape and volume
Phases of Matter
• Liquid- a form of matter that has a
constant volume and takes the shape of its
container
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Phases of Matter
• Gas a form of matter that
flows to conform to the
shape of its container and
fills the entire volume of
the container.
• http://www.youtube.com/
watch?v=IVc9Uz6zE1A
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Phases of Matter
• Solid- form of matter that has a definite
shape and volume
• Liquid- a form of matter that has a
constant volume and takes the shape of its
container
• Gas a form of matter that flows to conform
to the shape of its container and fills the
entire volume of the container.
• http://www.youtube.com/watch?v=IVc9Uz
6zE1A
Physical vs. Chemical Changes
In a physical change, the original
substance still exists; it has only changed
in form.
Physical vs. Chemical Changes
In a chemical change, a new substance is
produced. Energy changes always
accompany chemical changes.
Physical vs. Chemical Changes
In a chemical change, a new substance is
produced. Energy changes always
accompany chemical changes.
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Sodium hydroxide dissolves in water.
Hydrochloric acid reacts with potassium hydroxide to produce salt,
water, and heat.
A pellet of sodium is sliced in two.
Water is heated and changed to steam.
Potassium chlorate decomposes into potassium chloride and
oxygen gas.
Iron rusts.
When placed in water, a sodium pellet catches on fire as
hydrogen gas is liberated and sodium hydroxide forms.
Evaporation.
Ice melting.
Milk sours.
Sugar dissolves in water.
Wood rotting.
Pancakes cooking on a griddle.
Grass growing in a lawn.
A tire is inflated with air.
Food is digested in the stomach.
Water is absorbed by a paper towel.
• Can it be separated by ordinary physical
means?YesClassification of matterAll
MatterNo________________________Is
its composition uniform?Can it be broken
down by ordinary chemical
means?YesYesNoNo________________
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Matter—Properties and Change: Additional Concepts
Categories of Matter
Basic Assessment Questions
Warm-Up
Identify each of the following as an example
of a chemical change or a physical change.
A. Moisture in the air forms beads of water
on a cold windowpane.
B. An electric current changes water into
hydrogen and oxygen.
C. Yeast cells in bread dough make carbon
dioxide an ethanol from sugar.
Matter—Properties and Change: Additional Concepts
Categories of Matter
Matter—Properties and Change: Additional Concepts
Mixtures
• A mixture is a combination of two or more
pure substances in which each pure substance
retains its individual chemical properties.
• The composition of mixtures is variable, and
the number of mixtures that can be created by
combining substances is infinite.
Matter—Properties and Change: Additional Concepts
Mixtures
• Although much of the focus of chemistry is
the behavior of substances, it is important to
remember that most everyday matter occurs
as mixtures.
• Substances tend naturally to mix; it is
difficult to keep things pure.
Matter—Properties and Change: Additional Concepts
Mixtures
• Two mixtures,
sand and water,
and table salt and
water, are shown.
• You know water
to be a colorless
liquid
Matter—Properties and Change: Additional Concepts
Types of Mixtures
• Mixtures themselves are classified as either
heterogeneous or homogeneous.
• A heterogeneous mixture is one that does
not blend smoothly throughout and in which
the individual substances remain distinct.
• The sand and water mixture is an example of
a heterogeneous mixture.
• A homogeneous mixture has constant
composition throughout
• Mixtures can be separated by physical
means.
Mixtures can be different phases
• Chromotography- The separation occurs
because the various components of the
ink spread through the paper ant different
rates.
Other means of physical separation
• centrifuges/centrifuging *
• chromatography (paper/thin
layer) * * crystallisation *
• decanting/decantation *
• distillation
(simple/fractional) * * evaporation * filtrati
on * * magnet * mixture * molecule * * *
precipitation * * * purification * *
• sand/salt separation *
• separating funnel * separating mixtures * *
• . filtration
2. mechanical separation
3. flotation
4. centrifugation
5. distillation
6. crystallization
7. chromatography
8.boiling
9. freezing
10. decantation
11. sublimation
12. evaporation
13. magnetic separation
14. scooping
15. sedimentation
Matter—Properties and Change: Additional Concepts
Compounds
• A compound is a combination of two or
more different elements that are combined
chemically.
• Compounds have a unique
composition and formula.
• Water H20, table salt NaCl,
table sugar C12H22O11 , and
aspirin C9H8O4 are examples of
common compounds.
Matter—Properties and Change: Additional Concepts
Compounds
Compounds can be broken down
into simpler substances by
chemical means.
To separate a compound into
its elements often requires
external energy such as
heat or electricity.
• The properties of a
compound are different
from those of its component
elements. The example of
water illustrates this fact.
• Water is a stable compound
that is liquid at room
temperature.
• When water is broken down into its
components, it is obvious that hydrogen
and oxygen are dramatically different than
the liquid they form when combined.
http://www.youtube.com/watch?v=OTEX38b
Q-2w
Matter—Properties and Change
Periodic Table
Matter—Properties and Change: Additional Concepts
Categories of Matter
Mixtures vs Compounds
Mixtures
1. Variable composition
2. Can be separated by physical means
3. Components keep their properties
Compounds
1. Unique composition
2. Can be separated only by chemical means
3. Has properties different from its component
elements
Evidence of a chemical reaction
• The law of Conservation of Mass- mass
is neither created nor destroyed during a
chemical reaction; it is conserved
Mass Reactants = Mass Products
• http://www.youtube.com/watch?v=dExpJA
ECSL8
The Law of Definite Proportions• The Law of Definite Proportions- a
compound is always composed of the
same elements in the same proportions.
• Percent by mass (%) = mass of element ÷ mass of
compound X 100
Percent by mass (%) = mass of element ÷
mass of compound X 100
• http://www.youtube.com/watch?v=ithQj7X
ehW8&NR=1&feature=endscreen