Science 10
“ Imagination should give wings to our thoughts but we always
need decisive experimentive proof, and when the moment
comes to draw conclusions and to interpret the gathered
observations, imagination must be checked and documented by
the factual results of the experiment”
Louis Pasteur, 1864
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Unit 1
Energy and Matter in
Chemical Change
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1.0 Particles Make Up the Underlying
Structure of Matter
Enduring Understanding:
The understanding that particles make up the underlying structure
of matter has led to advancements in technology.
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Safety in the Lab
Properties and Classification of Matter
Developing Ideas of Matter
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1.1 Safety in the Lab
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Safety depends on awareness, knowledge and action
Must be aware of hazards and alert to unforeseen hazards
Must know how to use the right equipment and how to act in an
emergency
Must know how to behave safely and responsibly around
hazardous substances
Safety Rules have been developed to minimize the risk of
working with hazardous substances
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Safety Symbols
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(1)
(2)
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There are two systems developed for safety when working with
chemicals
WHMIS – Workplace Hazardous Materials Information System
HHPS – Household Hazardous Product Symbols
MSDS – Material Safety Data Sheet; Designed to provide
written information about chemicals, such as handling, storage,
disposal, reactivity, manufacturer
These systems have been developed to protect you and the
environment
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HHPS SYMBOLS
Explosive
Flammable
Poisonous
Corrosive
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1.2 Properties and Classification of
Matter
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(1)
(2)
Two types of properties that matter has:
Chemical:Describes the reactivity of the substance.
Ex. combustability, flammability, reactivity with water, ability to
neutralize
Physical: Describes the physical appearance and composition
of the substance
Ex. boiling/melting point, colour, density, state of matter,
ductility, malleability
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Chemical Reactions
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To observe a chemical property, you must see chemical change
How do you know if a chemical reaction has happened?
At least one new substance is produced
• Ex. Bubbles, A Precipitate
A change in colour
Energy is absorbed or released in the form of heat, light or sound
Odour is released
The reaction may be difficult to reverse
The reactants of a chemical change will have different chemical and
physical properties than the products
If a new substance is not produced (i.e. a change in state), then
only a physical change has occurred
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Classifying Matter
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Matter is often grouped and sub-grouped based on chemical
and physical properties
All matter can be classified as a pure substance or a mixture
In a pure substance, all of the particles that make up the
substance are identical
A mixture is a combination of two or more pure substances
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Pure Substances
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Pure substances can further be broken down into elements and
compounds
Elements cannot be broken down into smaller substances and
are found on the periodic table
Ex. Helium, Sodium, Lithium
Compounds are chemical combinations of two or more
elements in a fixed ratio
Ex. Water, Baking Soda, Carbon Dioxide
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Mixtures
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Mixtures can further be broken down into Homogeneous and
Heterogeneous Mixtures
A Homogeneous mixture is a solution because of the
consistent composition throughout the substance
Ex. Air, Coffee, Hydrochloric Acid
A Heterogeneous Mixture can be considered a Mechanical
Mixture, a Suspension or a Colloid
Mechanical Mixture: Different Substances are visible. Ex. Soil,
Cereal, Concrete
Suspension: The components are in different states of matter.
Ex. Italian Salad Dressing, Dirt Water
Colloid: Similar to the suspension, but the parts cannot be
easily filtered and separated. Ex. Ranch Salad Dressing, milk
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1.3 Developing Ideas of Matter
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Early people used their knowledge about the nature of matter to
meet their basic needs:
• Food Chemistry
• Metallurgy
• Alchemy
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Food Chemistry
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Heating: Raise the temperature to temporarily sterilize it
Freezing: Lowering the temperature to prolong decomposition
Salting: Adding salt to draw water out of meat
Fermentation: Biochemical method of food preservation that
maintains nutrient levels through use of bacteria called
lactobacilli, which convert sugar and starch into lactic acid
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Metallurgy
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Metallurgy is the science of producing and using metals
Ex. Use of gold to make jewellery, not weapons; too malleable
and rare
Ex. Use of copper to make weapons, such as spears, arrows and
knife blades
Ex. Use of copper to make handles for pots, staples and rivets
Ex. Smelting of tin with copper or iron with carbon to make
metal alloys
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Alchemy
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Alchemy is the combination of science and magic
Alchemists hoped to use chemical processes to try to turn cheap
materials into valuable substances, such as lead into gold
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The Development of the Atom
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Through this work, ancient people began to wonder what made
up matter
Atoms were proposed by Democritus thousands of years before
work of early scientists
Early scientists began to develop experiments to study matter
and the concept of atoms
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Robert Boyle and Antoine Lavoisier
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Boyle, through experimenting with the relationship between
volume and pressure of gasses, concluded that gases are made
of tiny particles
Lavoisier, through experimenting with chemicals during chemical
reactions, discovered that the mass of the reactants was always
the same as the mass of the products
This theory is known as the Law of Conservation of Mass
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John Dalton
(1766 – 1844)
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English chemist and physicist
Proposed that all atoms were like small solid spheres, but they
could have different properties
He claimed they varied in size, colour and mass
Often referred to as the Billiard Ball Model
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Dalton’s Atomic Theory
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Dalton also proposed a theory about atoms:
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All matter is made of small, invisible particles called
atoms
All atoms of an element have identical properties such
as size and mass
Atoms of different elements are not the same
Atoms can combine together in fixed ratios to form new
substances
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J.J. Thomson
(1856 – 1940)
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English physicist
Discovered the electron through experimenting with beams of
particles produced in a vacuum tube
Experiment showed that the beam was made of negatively
charged particles
Showed that different elements all produced the same negatively
charged beam
Proposed that the negative charge was embedded throughout a
positively charged atom
Known as the Plum Pudding Model/Raisin Bun Model
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Ernest Rutherford
(1871 – 1937)
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English scientist who began working with radioactive materials
Discovered the nucleus of atoms through gold foil experiment
Encased the radioactive material in lead with only a small
opening
This material released positively charged particles, which he
aimed at gold foil
The gold atoms would either have no effect on the beam, or
would slightly deflect it
1 in 10 000 particles would bounce back or be sharply deflected
Suggested that the atom was made of mostly space with a
dense, positively charged core
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Neils Bohr
(1885 – 1962)
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Danish Physicist
Proposed that electrons circle the nucleus in specific shells or
energy levels
Evidence for energy levels was based on hydrogen
When hydrogen is made to glow in a tube, it releases light in a
specific spectrum
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The Quantum Mechanical Model of
the Atom
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Today’s model of the atom
Abstract model that’s difficult to visualize
Electron location is based on mathematical probability
Electrons are thought of as a “cloud” of negative charge
Nucleus is made of nucleons: protons (positively charged) and
neutrons (neutrally charged)
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2.0 Elements Combine to Form
Compounds
Enduring Understanding:
Elements combine to form many substances, each with its own set
of properties
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The Periodic Table and Atomic Structure
Naming Ionic and Molecular Compounds
Properties and Classification of Ionic and Molecular Compounds
Acids and Bases
Our Chemical Safety
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Metals
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Metals share similar properties
Malleable, ductile, lustrous, solid at room temperature (except
for mercury), good conductors of heat and electricity
Found on the left side and center of the periodic table
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Non-Metals
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Non-metals are grouped based on their differences from metals,
rather than similarities to other substances
Brittle, can be solid, liquid and gas, dull, poor conductors of heat
and electricity
Gases commonly form molecular elements, or molecules of the
same element, Ex. H2
Found on the right hand side of the periodic table
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Metalloids
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Properties that are intermediate of metals and non-metals
Ex. Some conduct electricity, but not very well
Metalloids are found on the staircase dividing metals from nonmetals
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2.1 The Periodic Table and Atomic
Structure
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The periodic table organizes elements based on chemical and
physical properties
Periods refer to the horizontal rows of the periodic table, as the
properties of chemicals seem to repeat periodically as you travel
from one side of the table to the other
Groups or families refer to the vertical columns of the periodic
table
Chemical families share similar chemical properties
Different chemical families:
• Alkali Metals
• Alkaline-Earth Metals
• Halogens
• Noble/Inert Gases
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Alkali Metals
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Group 1
Most reactive group of metals
Soft, shiny and highly reactive with water
Form highly soluble compounds
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Alkaline – Earth Metals
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Group 2
2nd most reactive group of metals
Shiny, but not as soft as alkali metals
Form less soluble, often white compounds
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Halogens
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Group 17
Most highly reactive group of non-metals
Highly poisonous
React to form salts
Form molecular elements
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Noble/Inert Gases
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Group 18
Very unreactive gases
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The Atom
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The atom is the smallest part of an element, made of protons,
neutrons and electrons
Protons are located in the nucleus, are positively charged and
do not leave the atom during a chemical reaction
Electrons are located surrounding the nucleus, are negatively
charged and are exchanged or shared during a chemical reaction
Neutrons are located inside the nucleus, are neutrally charged
Protons and electrons are attracted to each other because they
are oppositely charged
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Using the Table to Find Subatomic
Particles
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Because an atom is neutrally charged in an atom, the number of
protons and electrons must be equal
The number of electrons and protons is equal to the atomic
number of the element
Because protons and neutrons make the majority of the atomic
mass of an atom, the number of neutrons is equal to the atomic
mass, rounded to the nearest whole number, minus the atomic
number
The number of neutrons may vary between atoms of the same
element, thus creating isotopes
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Energy Levels
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Electrons occupy energy levels, or a specific region of space
The energy levels closest to the nucleus have the lowest amount
of energy, and electrons in this level are tightly held to the
nucleus
The number of electrons that can occupy a region varies
depending on the level
The first level can hold 2 electrons, the second can hold 8, the
third can hold 8
Beyond this, the pattern is far more complicated
Energy levels can be empty, partially filled, or completely filled
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Formation of Ions
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Under some circumstances, an atom can gain or lose electrons to
become an ion
This occurs to create a more stable structure
Stability occurs when the last energy level contains the maximum
number of electrons possible
Atoms lose or gain electrons to become ions which have full valence
An element will gain electrons if it has over a half full last shell, thus
becoming negatively charged, as non-metals do, becoming anions
An element will lose electrons if it has less than half full last shell, thus
becoming positively charged, as metals do, becoming cations
This process is called ionization, as the new particle is called an ion
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The Octet Rule
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The Noble Gases have complete valence, thus explaining their
unreactivity
The octet rule is modeled on Argon and Neon, both containing
valences of 8
The Octet Rule states that atoms will bond in such a way as to
have 8 electrons in their valence levels
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2.2 Naming Ionic and Molecular
Compounds
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(2)
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Compounds can be broken into two basic types:
Ionic
Molecular
IUPAC (International Union of Pure and Applied Chemistry) is
responsible for developing names for compounds to maintain
consistency and set standards
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Ionic Compounds
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Bonds between metals and non-metals
Form as a result of a transfer of electrons to form ions
Ions have an electrostatic attraction that holds them together in a
crystal lattice
The ions are in specific ratio, depending on how many electrons were
transferred
Ex. sodium chloride (NaCl), baking soda (NaHCO3)
Ionic compound properties:
• Solid at room temperature
• High melting points
• Tend to dissolve in water
• Solutions of ionic compounds almost always conduct electricity
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Naming Ionic Compounds
(1)
(2)
(3)
(4)
(5)
(6)
Name the cation using the elements name
Name the anion only using the first part of the anion name, add
the ending “ide”
NO PREFIXES ARE USED
If the element has multivalence, need to balance the charges to
determine which valence is used, and then use Roman
Numerals to denounce the cation
If the compound contains a polyatomic ion, use the name of
the ion from the table of polyatomic ions; do not change the
ending from “ide” , “ite” or “ate”
Use only lower case letters; no capitals
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Writing Formulas for Ionic
Compounds
(1)
(2)
(3)
(4)
(5)
Identify the ions and their charges
Determine the ratio of positive to negative charges needed
Use subscripts to write the formula
If multivalence elements are used, use Roman Numerals to
indicate which element is being referred to
If Polyatomic ions are used, use brackets around the ion, and
write the subscript on the outside of the brackets
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Molecular Compounds
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Bonds between non-metals to form molecules
Form as a result of sharing electrons; do not form ions
Do not form crystal lattices, form independent particles with
elements combined in fixed ratios
Ex. carbon dioxide, glucose
Properties of Molecular Substances:
• Can be solid, liquid or gas
• Tend to be poor conductors, even when in solution
• Many do not dissolve in water very well
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Molecular Elements
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Molecules that are made up of only one type of element are
called molecular elements
Form to increase stability
Ex. H2(g), N2(g), O2(g), F2(g), Cl2(g), Br2(g), I2(g), P4(g), S8(g)
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Naming Molecular Compounds – No
Hydrogen
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(2)
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Name the first element using the elements name
Name the second element only using the first part of the
element name, add the ending “ide”
USE PREFIXES TO INDICATE HOW MANY OF EACH ELEMENT
HAS BEEN USED
If there is only one atom of the first element, no prefix is use
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Prefixes
1
2
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– mono
– di
– tri
–tetra
– penta
6 – hexa
7 – hepta
8 – octa
9 – nona
10 - deca
***7 is NOT ‘septa’ ***
(Southeastern Pennsylvania Transportation Authority)
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Naming Molecular Compounds –
Hydrogen Containing
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Many compounds of hydrogen have just been given names
H2O(l) – water
H2O2(l) – hydrogen peroxide
NH3(g) – ammonia
C12H22O11(s) – sucrose
C6H12O6(s) – glucose
CH4(g) – methane
C3H8(g) – propane
CH3OH(l) – methanol
C2H5OH(l) – ethanol
H2S(g) – hydrogen sulfide
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Writing Formulas for Molecular
Compounds
(1)
(2)
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Write the symbol for the first element, followed by the subscript
which matches the prefixes
Write the symbol for the second element, followed by the
subscript which matches the prefix
Use only lower case letters
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2.3 Properties and Classification of
Ionic and Molecular Compounds
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Ionic compounds have unique properties from molecular
compounds
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Properties of Ionic Compounds
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High Melting Point
• Have high melting points which make them solid at room
temperature
• Large amount of energy must be added to break the bonds
between cations and anions
Retention of Crystal Shape
• Retain crystal shape regardless of size of piece resulting from
the positive and negative alignment of the ions
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Properties Continued..
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Solubility in Water
• All ionic compounds dissolve to a certain extent due to the
attraction of the anions and cations to water molecules
• Water molecules are polar, with slightly positive and negative
regions within the molecule, thus the attraction
Conductivity of Solution
• When ionic compounds dissolve in water, free floating ions
occur, creating an electrolyte
• This electrolyte will conduct electricity
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Determining the Solubility of an Ionic
Compound
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Use a solubility chart
Find the anion along the top of the chart
Go down the column to find the cation
Determine the solubility
Use subscript (aq) to symbolize highly soluble
Sometimes when ionic compounds are mixed, they will form a
precipitate, a solid with low solubility
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Properties of Molecular Compounds
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Low Melting Point
• Have low melting points
• The attraction between molecules is very weak and easily
broken using heat energy
• The compound does not separate, only the molecules
Crystal Shape
• When molecular compounds form crystals, they are easily
crumbled due to the weak attractive forces between the
bonds
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Properties Continued..
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Solubility in Water
• Recall, polar refers to slight separation of positive and
negative charges within a molecule, thus creating positive and
negative areas
• If the molecule is polar, it will dissolve in water, because
water is polar
• If the molecule is non-polar, it will not dissolve in water
Poor Conductivity of Solution
• Molecular compounds do not conduct electricity, even when
in solution
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2.4 Acids and Bases
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Acids have unique properties from bases
*Coke Classic*
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Properties of Acids
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Solutions that have a pH less than 7
Contain H+ ion
Taste Sour
Feel Wet
Corrosive
React with metals
React with litmus to turn red
Turn phenolphthalein clear
Turn bromthymol blue yellow
Conduct electricity
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Naming Acids
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Hydrogen _______ide  hydro _______ic acid
Hydrogen _______ate  _______ic acid
Hydrogen _______ite  _______ous acid
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Properties of Bases
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Solutions that have a pH greater than 7
May contain (OH)- ion
Taste bitter
Feel Slippery
Corrosive
Do not attack metals
React with litmus to turn blue
Turn phenolphthalein pink
Turn bromthymol blue blue
Conduct electricity
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Neutralization
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When acids and bases react together, the new substance
becomes more neutral, moving closer to a pH of 7, thus
neutralization has occurred
When an acid reacts with a base, water and a salt are formed
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Acids and Bases at Home
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Bases tend to be found in many chemical cleaners, especially to
clean off grease or oil
Acids tend to be found in our food, but can also be used as
cleaners
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2.5 Our Chemical Society
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Issues related to Chemicals
• Environmental effects and toxic effects related to humans
need to be considered
Health Concerns
• Damaging effects of alcohol and nicotine
Regulated Substances
• Benzene, due to its level of danger must be highly controlled
and regulated
Chemistry Related Careers
• Food Technologists, Cosmetic Formulator, Engineers
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3.0 Chemical Change
Enduring Understanding:
Chemical change is a process that involves recombining atoms and
energy flows
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Important Examples of Chemical Change
Writing Chemical Equations
Five Common Chemical Reactions
The Mole
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3.1 Important Examples of Chemical
Change
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In a chemical reaction, the chemicals reacting together are called
reactants
The chemicals produced are called the products
The reactants are written on the left hand side of a chemical
equation, and are separated by an arrow from the products,
which are written on the right hand side of the arrow
Recall that the products will have new and different properties
than the reactants
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Indicating State of Matter
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Indicate the state of matter of the chemical by using subscripts,
gas (g), liquid (l), solid (s) and aqueous (aq)
All ionic compounds are solid at room temperature
If added to solution, they may be aqueous; need to consult chart
Molecular states are hard to predict. Generally small molecular
compounds tend to be gases, large tend to be solids
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Energy Change and Chemical
Reactions
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Energy flow is an essential part to chemical reactions
Energy can be either released or absorbed
Exothermic describes reactions which release energy, usually in
the form of heat, light or electricity
Ex. A Battery, Combustion
Endothermic describes reactions which absorb energy
Ex. A Cold Pack, Cooking
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3.2 Writing Chemical Equations
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Two ways to represent chemical reactions is using a chemical
equation or a word equation
Chemical Equation:
• 6CO2(g) + 6H2O(l)  C6H12O6(s) + 6O2(g)
Word Equation:
• carbon dioxide reacts with water to produce glucose and
oxygen gas
• carbon dioxide + water  glucose + oxygen
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Balancing Chemical Equations
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Because of the Law of Conservation of Mass, the number of
atoms used in the reaction must be conserved, thus it is
necessary to balance the equation using whole number
coefficients
The chemical formula is not changed, only a coefficient is added
in front of the compound to indicate the number of compounds
reacting
The lowest possible combination of compounds is used
When Balancing, try balancing:
• Metals
• Polyatomic Ions
• Non-Metals
• Hydrogen
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• Oxygen
3.3 Five Common Chemical Reactions
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Formation
Decomposition
Single Replacement
Double Replacement
Hydrocarbon Combustion
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Formation, Simple Composition or
Synthesis
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A + B  AB
Element + element  compound
Na(s) + Cl2(g)  NaCl(s)
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Decomposition
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AB  A + B
Compound  element + element
NaCl(s)  Na(s) + Cl2(g)
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Single Replacement
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Element + compound  element + compound
A + BC  B + AC, where the metallic element replaces the
metal in the compound
Na(s) + MgBr2(s)  Mg(s) + NaBr(s)
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Double Replacement
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compound + compound  compound + compound
AB + CD  AD + CB, where the metallic element in the first
compound replaces the metallic element in the second
compound
NaI(s) + MgBr2(s)  MgI2(s) + NaBr(s)
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Hydrocarbon Combustion
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Hydrocarbon compound + oxygen  water + carbon dioxide
CxHx + O2(g)  H2O(l) + CO2(g)
Balance the following equation:
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__C3H8(g) + __O2(g)  __H2O(l) + __CO2(g)
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Check your work
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C3H8(g) + 5O2(g)  4H2O(l) + 3CO2(g)
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Predicting the Products of a Chemical
Reaction
(1)
(2)
(3)
(4)
Classify the reaction as one of the five reaction types
Predict the products resulting based on the reactions pattern
Re-write the chemical formulas for the products
Balance the equation
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3.4 The Mole
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Atoms are too small to measure using our metric system
Atoms must be grouped together when measuring their mass
This group is extremely large due to the small nature of atoms
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Avogadro’s Number and the Mole
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The grouping that chemists use is called the mole (mol)
There are 6.02 x 1023 particles in one mole
This many atoms is referred to as Avogadro’s number, named
after the Italian scientist Amedeo Avogadro
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Molar Mass of Elements
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To find the mass of one mole of any element, look at the atomic
mass
This is called the Molar Mass
Ex. 1 mole of hydrogen has a mass of 1.01 g, thus, 6.02 x 1023
hydrogen atoms have a mass of 1.01g
If you have a fraction of one mole, or more than one mole, you
can calculate the mass by using the formula:
m=nxM
m = mass (g)
n = number of moles (mol)
M = molar mass (g/mol)
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Molar Mass of Compounds
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To find the molar mass of compounds, simply add the molar
mass of the individual elements that make up the compound
In a balanced chemical equation, the number of moles of each
compound is indicated by the coefficients
• 6CO2(g) + 6H2O(l)  C6H12O6(s) + 6O2(g)
Ex. 6 moles of CO2(g) + 6 moles of H2O(l) 1 mole of C6H12O6(s)
+ 6 moles of O2(g)
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