Unit
1:
Stiochiometry
and
Partial
Pressure
Name:
____________________________
Date:
______________________________
2.7
Stiochiometry
of
Gases
eg.
1
Balancing
Equations
1]
____
N2
(g)
+
___
H2
(g)

___
NH3
(g)
2]
____
C3H8
(g)
+
___
O2
(g)

___
CO2
(g)
+
___
H2O
(g)
3]
____
C2H5OH
(g)
+
___
O2
(g)

___
CO2
(g)
+
___
H2O
(g)
4]
___
B2O3
(s)
+
___
H2O
(g)

___
B2H6
(g)
+
___
O2
(g)
eg.
2
Stiochiometric
Calculations
If
18
moles
of
N2
reacts
to
completion,
how
many
moles
of
NH3
(g)
will
be
produced?
20
moles
of
O2
reacts
with
sufficient
propane.
How
many
moles
of
carbon
dioxide
are
produced?
When
we
solve
problems
involving
gases
and
chemical
________________,
one
can
use
the
_______________,
__________________
and
__________________
gas
laws
to
determine
unknowns
for
the
initial
and
final
states.
Unknowns
such
as
____,
_____,
_____,
and
_____.
To
accomplish
this,
one
must
first
apply
stiochiometric
calculations
involving
mole
____________
to
identify
the
number
of
moles
in
either
the
products
or
the
reactants
depending
on
what
we
are
looking
for.
eg.
3
Gas
Stiochiometry
2.5
moles
of
methane
(CH4)
at
273
K
react
completely
with
5.0
moles
of
oxygen
(O2)
in
a
40
L
container
at
a
pressure
of
4
atm.
What
will
the
final
pressure
be
in
container
if
the
temperature
increases
to
350
K?
____
CH4
(g)
+
___
O2
(g)

___
H2O
(g)
+
___
CO2
(g)
Unit
1:
Stiochiometry
and
Partial
Pressure
2.8
Partial
Pressure
of
a
Gas
Dalton’s
Law
of
partial
pressures
states
that
the
____________
pressure
of
a
gas
mixture
is
the
__________
of
the
pressure
for
each
_________________
species
of
gas.
In
other
words….
Total
Pressure
Species
A
Species
B
Species
C
eg.
4
This
is
how
Dalton’s
law
works
in
practice.
+
_____
_____
_____
_____
To
determine
the
partial
pressure
of
a
specific
gas
in
the
mixture
given
the
total
pressure
of
the
mixture,
take
the
number
of
moles
of
this
species
divided
by
the
total
#
of
moles
in
the
mixture.
This
is
also
the
mole
____________________________.
Moles
of
Species
A
_____
Totals
in
Mixture
_____
Total
Pressure
Partial
Pressure
of
A
_____
_____
eg.
5
At
a
given
temperature
a
mixture
of
gas
contains
3.35
mol
of
neon
(Ne),
0.64
mol
of
argon
(Ar)
and
2.19
mol
of
xenon
(Xe).
What
is
the
partial
pressure
of
xenon
if
the
total
pressure
of
the
mixture
is
200.0
kPa?
Unit
1:
Stiochiometry
and
Partial
Pressure
1.
The
combustion
of
ammonia
(NH3)
by
oxygen
(O2)
produces
water
and
nitrogen
gas.
a)
Balance
the
equation.
b)
Determine
the
mass
of
oxygen
needed
to
completely
burn
16.0
mol
of
ammonia.
____
NH3
(g)
+
____
O2
(g)

____
N2
(g)
+
____
H2O
(g)
2.
Determine
the
mass
in
grams
of
nitrogen
(N2)
produced
when
2.72
mol
of
hydrazine
(N2H4)
are
consumed
after
having
balanced
the
equation
of
the
following
reaction:
____
N2H4
(l)
+
____
N2O4
(l)

____
N2
(g)
+
____
H2O
(g)
3.
In
a
barbecue,
35
g
of
propane
(C3H8)
gas
are
burned
according
to
the
following
equation:
a) What
is
the
volume
of
water
vapour
produced?
b) What
is
the
volume
of
oxygen
(O2)
used?
C3H8
(g)
+
5O2
(g)

3CO2
(g)
+
4H2O
(g)
Unit
1:
Stiochiometry
and
Partial
Pressure
4.
Nitrogen
monoxide
(NO)
is
one
of
the
gases
that
causes
smog.
It
is
produced
in
different
ways,
especially
during
the
combustion
of
ammonia
(NH3).
What
mass
of
nitrogen
monoxide
is
produced
if
25.0
L
of
ammonia
react
with
27.5
L
of
oxygen
(O2)
at
STP?
4
NH3
(g)
+
5
O2
(g)

4
NO
(g)
+
6
H2O
(g)
5.
To
accelerate
a
reaction
in
a
container
under
a
pressure
of
98
kPa,
a
chemist
adds
hydrogen
(H2)
gas
at
202.65
kPa.
What
is
the
resulting
pressure?
6.
A
mixture
of
neon
(Ne)
and
argon
(Ar)
is
collected
at
102.7
kPa.
If
the
partial
pressure
of
the
neon
is
52.5
kPa,
what
is
the
partial
pressure
of
the
argon?
7.
The
partial
pressure
of
argon
(Ar),
which
constitutes
40%
of
a
mixture,
is
325
mm
Hg.
What
is
the
total
pressure
of
the
mixture
in
kilopascals
(kPa)?
8.
What
is
the
volume
of
a
weather
balloon
if
it
contains
10
mol
of
air
at
75.5
kPa
and
‐45oC?