Podcast 7.1 Chemical Reactions.mp4
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Describing Chemical Reactions
Evidence of Chemical Reactions
Chemical Sentences
Word Equations
Example
Other Symbols to know…
Other Symbols to know…
Catalyst
Writing Chemical Equations:
Law of Conservation of Matter: Matter Cannot be Created or Destroyed in a Chemical or Physical Process.
Examples
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CC
Describing
Chemical
Reactions Chemical
ReactionsOccur
every
day
all
the
time
iron
of
glucose
hydrogenHomeostasis
in
Living
Organisms 2
Evidence
of
Chemical
Reactions Color
changepH
changeEnergy
(gets
hotter
or
colder)
of
a
precipitateProduction
of
a
3
Chemical
Sentences
Names
of
elements
or
are
used
to
indicate
substances
and
the
amounts
used
in
a
reactionExample:2H2
+
O2
2H2OChemical
SentenceTwo
of
hydrogen
gas
reacts
with
molecule
of
oxygen
gas
to
produce
(yield)
two
molecules
of
. 5
Word
Equations Names
of
elements
or
compounds
are
used
to
indicate
substances
and
the
amounts
used
in
a
Example:2H2
+
O2
2H2OWord
Equation
gas
+
gas
6
Example
Fe(s)
+
O2(g)
Fe2O3(s)What
are
the
products?What
are
the
reactants?What
is
the
word
sentence?What
is
the
word
equation?
H2O 7
Other
Symbols
to
know… (s)
=
substance
is
in
a
solid
state(l)
=
substance
is
in
a
state(aq)
=
aqueous
solution
-
substance
is
dissolved
in
(g)
=
substance
is
in
a
gaseous
state 8
Other
Symbols
to
know… +
=
used
to
separate
two
reactants
or
two
products
=
separates
from
products
=
for
reactions
or
=
indicate
that
heat
is
used
in
the
reaction
=
A
formula
(could
be
any
–
in
this
case
platinum)
indicates
it
is
used
as
a
Pt
Heat 9
Catalyst A
substance
that
up
a
chemical
reaction
but
is
not
used
in
the
reactionExample:Fe(s)
+
O2(g)
Fe2O3(s)What
are
the
in
this
reaction?What
phase
state
is
each
substance
in
for
this
reaction?
H2O 10
Writing
Chemical
Equations: Reactants
→
ProductsWord
EquationsIron
+
Oxygen
→
Iron
(III)
oxideChemical
EquationsFe
+
O2
→
Fe2O3
Fe(s)
+
O2(g)
→
Fe2O3(s) 11
Law
of
Conservation
of
Matter:Matter
Cannot
be
Created
or
Destroyed
in
a
Chemical
or
Physical
Process. Balanced
Equations
–
both
sides
of
the
equation
must
have
the
number
of
atoms
for
each
element**only
coefficients
may
be
adjusted
to
balance
an
equation,
change
the
subscripts,
which
identify
the
substance
itself 12
Examples C(s)
+
O2(g)
→
CO2(g)Fe(s)
+
S8(s)
FeS
(s)**Look
out
for
BrINClHOF
elements!
They
are
diatomic
in
their
form..**You
can
change
the
,
but
not
the
Identity
of
a
substance! 13