TOPIC 1
STOICHIOMETRIC
RELATIONSHIPS
1.1
INTRODUCTION TO THE PARTICULATE
NATURE OF MATTER AND CHEMICAL
CHANGE
ESSENTIAL IDEA
Physical and chemical properties
depend on the ways in which
different atoms combine.
NATURE OF SCIENCE (3.1)
Making quantitative measurements with
replicates to ensure reliability – definite and
multiple proportions.
UNDERSTANDINGS/KEY IDEA
1.1.A
Atoms of different elements combine
in fixed ratios to form compounds,
which have different properties from
their component elements.
UNDERSTANDINGS/KEY IDEA
1.1.B
Mixtures contain more than one
element and/or compound that are
not chemically bonded together and
so retain their individual properties.
UNDERSTANDINGS/KEY IDEA
1.1.C
Mixtures are either homogeneous or
heterogeneous.
Chemistry:
Chemistry is the study of what
things are made up of, and the
changes that they undergo
MATTER
Anything that has mass
and takes up space
(Pure) Substances
Mixtures
Physical combinations of two or
more substances
Homogeneous Heterogeneous
Uniform throughout, Not uniform throughout,
aka “solution”;
distinct pieces;
Think: smoothie
Think: fruit salad
Pure Substances:
Elements & Compounds
 occur
naturally, same composition
throughout the substance and everywhere
in the world
MATTER
Stuff that has mass
and takes up space
(Pure) Substances
Have a specific or definite composition
(homogeneous)
Elements
Compounds
Mixtures
Physical combinations or two or
more substances
Homogeneous Heterogeneous
Uniform throughout, Not uniform throughout,
aka “solution”;
distinct pieces;
Think: smoothie
Think: fruit salad
Elements
 Elements:



The simplest form of matter
Cannot be broken down or separated into a
simpler substance
Building blocks for all other substances
Found on the periodic table of elements
MATTER
Anything that has mass
and takes up space
(Pure) Substances
Have a specific or definite composition
(homogeneous)
Elements
Examples: iron
sulfur, carbon,
Hydrogen, oxygen
Compounds
Mixtures
Physical combinations of two or
more substances
Homogeneous Heterogeneous
Uniform throughout, Not uniform throughout,
aka “solution”;
distinct pieces;
Think: smoothie
Think: fruit salad
Compounds
 Compounds:
Chemical combination of 2 or
more substances


Cannot be physically separated
Have properties different than the elements
that are combined
MATTER
Stuff that has mass
and takes up space
(Pure) Substances
Have a specific or definite composition
(homogeneous)
Elements
Examples: iron
sulfur, carbon,
Hydrogen, oxygen
Compounds
Examples: water,
salt, sugar
Mixtures
Physical combinations of two or
more substances
Homogeneous Heterogeneous
Uniform throughout, Not uniform throughout,
aka “solution”;
distinct pieces;
Think: smoothie
Think: fruit salad
APPLICATION/SKILLS
Be able to deduce chemical
equations when reactants and
products are specified.
 Atoms
cannot be created or destroyed in a
chemical reaction, they can only be
rearranged.
 The reactants (substances on the left side
of the arrow) are transformed into products
(substances on the right side of the arrow).
 All chemical reactions must be balanced –
the number of atoms of each element
must be the same on each side of the
equation.
 The
coefficients in an equation give the
molar ratios of the reactants and products.
2H2(g) + O2(g)  2H2O(l)
This tells us that 2 moles of hydrogen
react with 1 mole of oxygen to
produce 2 moles of water.
2H2(g) + O2(g)  2H2O(l)
 The
mole ratio is a ratio of the coefficients
in the balanced chemical equation.
 When working stoichiometry problems, the
coefficient for the unknown is always on
top.
 The mole ratio of hydrogen to oxygen is 2
to 1.
 The mole ratio of oxygen to water is 1 to 2.
APPLICATION/SKILLS
Be
able to apply the state
symbols (s), (l), (g) and (aq)
in equations.
2H2(g) + O2(g)  2H2O(l)







The states of substances are indicated in
parenthesis next to the formula.
Solid (s)
Liquid (l)
Gas (g)
Aqueous solution (aq) – indicates that the ions
are dissolved in water.
A single arrow  means the rxn essentially goes
to completion.
A double arrow
means equilibrium.
APPLICATION/SKILLS
Be able to explain the
observable changes in physical
properties and temperature
during changes of state.
Heating/Cooling Curve
www.gcps.desire2learn.com
APPLICATION/SKILLS
Be able to name the changes
of state – melting, freezing,
vaporization (evaporation and
boiling), condensation,
sublimation and deposition.
Melting: solid to liquid
Freezing: liquid to solid
Vaporization: liquid to gas
Condensation: gas to liquid
Sublimation: solid to gas
Deposition: gas to solid
APPLICATION/SKILLS
Be able to balance a variety of
reaction types.
5 Basic Types of Reactions
 1.
Combination or synthesis
 2. Decomposition
 3. Single Replacement
 4. Double Replacement
 5. Combustion
Combination
 Reaction
where 2 substances combine
into a single substance.
 A + B → AB
Decomposition
 Reaction
where 1 substance breaks into 2
or more substances.
 AB → A + B
Single Replacement
 Reaction
where an element replaces a
similarly charged ion in a compound.
 A + BC → B + AC
Double Replacement
 Reaction
where two compounds react to
produce two new compounds.
 AD + BC → BD + AC
Write the charges on top of the elements in
the reactants and exchange the positive ions
to make new compounds.
You must have a positive followed by a
negative to make a compound.
Combustion
 Reaction
where an element or
compound(usually a hydrocarbon) reacts
with oxygen.
 A + O2 → AO2
 CH2 + O2 → CO2 + H2O
The first example is simply a combination
reaction.
The second example with the hydrocarbon
always produces CO2 and H2O.
Citations
Brown, Catrin, and Mike Ford. Higher Level
Chemistry. 2nd ed. N.p.: Pearson Baccalaureate,
2014. Print.
Most of the information found in this power point
comes directly from this textbook.
The power point has been made to directly
complement the Higher Level Chemistry textbook by
Catrin and Brown and is used for direct instructional
purposes only.