Can you teach me about Introduction
for Reactions Identify evidence of chemical
and physical changes in
matter. A physical change occurs when a substance
undergoes a change in properties but not a
change in composition. Changes in the phase
of a substance (solid, liquid, gas) or formation/
separation of mixtures of substances are
common physical changes. A chemical change occurs when substances
are transformed into new substances, typically
with different compositions. Production of
heat or light, formation of a gas, formation
of a precipitate, and/or color change provide
possible evidence that a chemical change
has occurred. Net Ionic
Equations Represent changes in matter
with a balanced chemical or
net ionic equation:
a. For physical changes.
b. For given information
about the identity of the
reactants and/or product.
c. For ions in a given
chemical reaction. All physical and chemical processes can
be represented symbolically by balanced
equations.Chemical equations represent chemical
changes. These changes are the result
of a rearrangement of atoms into new
combinations; thus, any representation of a
chemical change must contain equal numbers
of atoms of every element before and after the
change occurred. Equations thus demonstrate
that mass is conserved in chemical reactions.Balanced molecular, complete ionic, and net
ionic equations are differing symbolic forms
used to represent a chemical reaction. The
form used to represent the reaction depends
on the context in which it is to be used.
Representations
of ReactionsRepresent a given chemical
reaction or physical
process with a consistent
particulate model.Balanced chemical equations in their various
forms can be translated into symbolic
particulate representations.Physical and
Chemical Changes Explain the relationship
between macroscopic
characteristics and bond
interactions for:
a. Chemical processes.
b. Physical processes Processes that involve the breaking and/or
formation of chemical bonds are typically
classified as chemical processes. Processes
that involve only changes in intermolecular
interactions, such as phase changes, are
typically classified as physical processes.Sometimes physical processes involve the
breaking of chemical bonds. For example,
plausible arguments could be made for
the dissolution of a salt in water, as either
a physical or chemical process, involves
breaking of ionic bonds, and the formation
of ion-dipole interactions between ions
and solvent.Stoichiometry Explain changes in the
amounts of reactants and
products based on the
balanced reaction equation
for a chemical process.Because atoms must be conserved during a
chemical process, it is possible to calculate
product amounts by using known reactant
amounts, or to calculate reactant amounts
given known product amounts.Coefficients of balanced chemical
equations contain information regarding the
proportionality of the amounts of substances
involved in the reaction. These values can be
used in chemical calculations involving the
mole concept.Stoichiometric calculations can be combined
with the ideal gas law and calculations involving
molarity to quantitatively study gases
and solutions. Introduction to Titration
Identify the equivalence
point in a titration based on
the amounts of the titrant
and analyte, assuming
the titration reaction goes
to completion. Titrations may be used to determine the
concentration of an analyte in solution. The
titrant has a known concentration of a species
that reacts specifically and quantitatively
with the analyte. The equivalence point of the
titration occurs when the analyte is totally
consumed by the reacting species in the
titrant. The equivalence point is often indicated
by a change in a property (such as color) that
occurs when the equivalence point is reached.
This observable event is called the endpoint of
the titration. Types of Chemical
Reactions Identify a reaction as acidbase, oxidation-reduction, or
precipitation.  Acid-base reactions involve transfer of one or
more protons between chemical species. Oxidation-reduction reactions involve transfer
of one or more electrons between chemical
species, as indicated by changes in oxidation
numbers of the involved species. Combustion
is an important subclass of oxidation-reduction
reactions, in which a species reacts with
oxygen gas. In the case of hydrocarbons,
carbon dioxide and water are products of
complete combustion. In a redox reaction, electrons are transferred
from the species that is oxidized to the species
that is reduced. Oxidation numbers may be assigned to each of
the atoms in the reactants and products; this is
often an effective way to identify the oxidized
and reduced species in a redox reaction. Precipitation reactions frequently involve
mixing ions in aqueous solution to produce an
insoluble or sparingly soluble ionic compound.
All sodium, potassium, ammonium, and nitrate
salts are soluble in water. Introduction to
Acid-Base Reactions Identify species as BrønstedLowry acids, bases, and/or
conjugate acid-base pairs,
based on proton-transfer
involving those species. By definition, a Brønsted-Lowry acid is a
proton donor and a Brønsted-Lowry base is a
proton acceptor.
 Only in aqueous solutions, water plays an
important role in many acid-base reactions,
as its molecular structure allows it to accept
protons from and donate protons to
dissolved species. When an acid or base ionizes in water, the
conjugate acid-base pairs can be identified and
their relative strengths compared. Oxidation-Reduction
(Redox) Reactions Represent a balanced redox
reaction equation using
half-reactions. Balanced chemical equations for redox
reactions can be constructed from
half-reactions.