Unit 2: Matter, Energy,
Properties and Change
Pretest
Give an example of a chemical change
2. Give an example of a homogeneous mixture.
3. What is the molar mass of carbon?
4. State the Law of Conservation of matter.
5. Can matter be changed into energy? If so, give the formula.
6. What is the molar mass of water (H2O)?
7. Calculate the percent composition of all the elements in water.
8. Give an example of each: element and a compound
9. How many chemical elements are there?
10. Describe a chemical reaction at the molecular level.
1.
Some terms
 Matter – anything that has mass and takes up space
 Inertia – resistance to a change in motion
 Substance – cannot be broken down by physical means
(filtration, recrystallization, distillation, etc), uniform
and unchanging in composition, ex NaCl
 A pure substance is either a compound or an element.
Kinetic Theory of Matter
 All matter has some kinetic energy
 Kinetic energy (speed) depends on
temperature (variable) and mass (constant).
 The particles of matter are in constant
motion
 If collisions occur, the collisions are elastic –
they lose no energy
States of Matter
 Solid – definite volume/shape; particles vibrate
 Liquid – definite volume, not shape; particles flow
overtop of each other
 Gas – no definite shape/volume; particles spread
out due to high KE
 Plasma – particles move so fast and violently that
they break down into electrons and positive nuclei
 BEC (Bose Einstein Condensate) - … a 5th state?
In 2003 a Bose-Einstein condensate was formed by
chilling a gas to absolute zero (-273.15°C), where
the motion of the particles slows and they
combine in a single “super atom”. Very low energy.
Solid shapes can be…..
a)Amorphous
(no definite
arrangement)
(graphite)
b)Crystalline
(is a definite
arrangement)
(diamond)
Changes of Phase (State)
Element
 The smallest particle of an element that retains its
properties.
 A pure substance that cannot be separated into
simpler substances by physical or chemical means
 Examples: any on PT (118)
 92 naturally occurring
 Not the same in abundance
 75% of universe is H
 75% of earth’s crust is Si and O
Compound
 2 or more different elements combined chemically
 ~10 million known compounds
 Discovered at a rate of 100,000 per year
 Can be broken down into simpler substances by
chemical means
 Properties of compounds are different from
element components
 Example: NaCl,
Mixtures
 – combination of 2 or more pure substances (retains
each individual chemical properties) – can be
separated (by physical means)
 Water - ? Pond water vs tap water vs distilled
 Salt - ?
 Salt water - ?
Ocean water?
 Examples:
 Heterogenous mixture – does not blend smoothly
throughout, individual substances remain distinct
 Examples:
 Homogeneous mixture – has a constant composition
throughout and always has a single phase; also called a
solution
 Examples: Strawberry milkshake
Separating Mixtures
 Filtration – uses a porous barrier to separate solids
from liquids, based on particle size
 Distillation – based on differences in the boiling points
of substances involved
 Crystallization – results from the formation of
pure solid particles of a substance from a solution
containing dissolved substances
 Chromatography – separates on the basis of the
tendency (adsorbption) of each to travel across the
surface of another material
Properties
 Physical property – can be observed or measured
without changing the sample’s composition
 Examples:
 Extensive properties: depend on the amount of
substance present
 Intensive properties: independent of the amount of
substance present
 Chemical Property – the ability of a substance to
combine with or change into one or more other
substances
 Examples:
Changes in Matter
 Physical change - changes which alter a substance
without changing its composition
 Example:
About nine states of
matter exist…. like
critical fluids
 Chemical Change – a process that involves 1 or more
substances changing into new substances
 Example:
Chemical change (reaction) vs physical change
Boiling? Melting? Tearing? Carmelizing?
Evidence of a Chemical Change
 Change in color
 Change in smell
 Change in temperature
 Endothermic –
 Exothermic –
 Gas released (bubbles)
 Precipitate forms (solid forms)
****Must be careful with these – one by itself is not
definite proof
Bellringer
 How many?
 Bose-Einstein condensate….
 Draw the heating curve for water.
Law of Conservation of Mass
 Mass is neither created nor destroyed during a
chemical reaction – it only changes form. It is
conserved.
 mreactants = mproducts

A student separated water into hydrogen and oxygen.
He collected 10.0 g of hydrogen and 79.4 g of oxygen.
How much water was involved in the process?

A 10.0 g sample of magnesium reacts with oxygen to
form 16.6 g of magnesium oxide. How many grams of
oxygen reacted?
Law of Conservation of Energy
Energy can neither be created
NOR destroyed, only
transformed.
Energy is never “LOST”, just
changed into a non-useful form.
Law of Conservation of MatterEnergy
The total amountof matter and
energy must stay the same, but
matter can be transformed into
energy and vice-versa.
c= velocity of light
2
E=mc
300, 000, 000 m/s or
186, 000 miles/sec
Bookwork
 Pg 48
 Restate the question
 Do #7, 8, 14, 24, 28-32
Bookwork
 Page 52 Restate the question
 # 23
 Page 58 # 35-40, 42, 47, 54, 55, 56, 58, 60-63, 67, 69, 74
 Page 61 # 1-10
Groupwork
 Pg 60 #74-77, 82
 Pg 61 #11-14
Bellringer
1.
2.
3.
4.
5.
Give 2 evidences that a chemical change is
happening.
Give 2 examples of a chemical change.
Is the “volume” an example of an extensive or an
intensive physical property?
Is the “density” an example of an extensive or an
intensive physical property?
Chromatography is a method of separating the
components in a __________ based on their
solubility in a solvent.
Calculations: Percent composition
 Determine % comp for each element in:
 A) water
 B) carbon dioxide
 C) ammonia (% hydrogen only)
Calculations: Percent composition
 Determine % comp for the element stated
in:
 A) % hydrogen in sulfuric acid
 B) % oxygen in ethanol
 C) % carbon in cholesterol (2,15-dimethyl-14-(1,5dimethylhexyl)tetracyclo[8.7.0.02,7.011,15]heptadec-7-en-5ol), C27H46O
Liquids
 Intermolecular forces
 Intramolecular forces
 Evaporation
 Vaporization
 Boiling
 Boiling diagram
 Cooling process
Vapor pressure
 VP indicates how volatile a liquid is
 Boiling point
 Sea level vs mountain top
 Pressure changes
Special Properties of Water
 Expands when freezes, most solids constrict
 Hydrogen bonding
 Makes boiling and melting point much higher
 Ice is less dense than water due to H bonding – ice floats
 Cohesion: forces between identical molecules
 Adhesion: forces between different molecules
 Capillary rise (action) – rise of a liquid in a tube of small
diameter due to unbalanced forces
 Why does water exhibit capillary action? Cohesion or Ad
 Surface tension – apparent elasticity of the surface of a
liquid due to unbalanced forces
 Water has a high surface tension. Why? Co or Ad?
Solids
 Melting diagram
 Crystal structures
 Crystalline vs amorphous
 Glass see page R20
 Diamond vs graphite
 Allotropes
 Fullerenes See R21
Tutorials + videos
 https://www.youtube.com/watch?v=P_RQuRzp7SE
Bozeman what students should know 11 min
 https://www.youtube.com/watch?v=VkeSI_B5Ljc what
is a plasma Plasma Lab MD
 http://www.livescience.com/46506-states-ofmatter.html 5 states of matter
 https://www.youtube.com/watch?v=yBRdBrnIlTQ
Supercritical fluid Nottingham
Today
 Finish Chromatography Lab
 Discuss Lab Safety test retake results
 Binder checks
 Turn in
 Happy Fall Break!