2-13: Creating a Solut i on of Known Molarity In this assignment, y o u will weigh out asa m p le of baking soda (NaHC O 3 ) and create a solution ofknown m o l arit y . 1.   Start VirtualChemLab, select Reactions and Stoichiometry, and then select Creating aSolut i on of Known M o larity from t he list of assig n m ents.The lab will open in the Ti t ration laborato r y . 2.   In the labora t o r y , a bot t le of baking soda (sodiumbicarbonate, NaHCO 3 ) will be next to thebalance, and an e m ptybeaker will be on the stir plate.  Drag the e m ptybeaker to the spot l ight next t o t h e balance, clickin the Ba l an c e area to zoomin, place aweigh paper on the balan c e, and tare the balance. 3.   Open the bot t le by clicking on the l i d ( Remove Li d ). Pick up the S c oo p and scoop out so m e sa m ple by first dragging the scoop tothe m outh of the bottle and then pull i ngthe scoop down the face of the bottle. As the scoop is dragged down t h e face of the bottle it will p i ckup different quantities ofsolid. Select the largest sa m ple possible and d r ag the scoop t othe weighing paper on th e balance until it snaps in place and then let go.  This will put app r oximately1 gofsa m ple on the balance.  Repeat with a second Scoop . Record the m a ss of the NaHCO 3 in the data table. 4.   Drag the we i gh paper to the beaker and add the NaHC O 3 sa m p le t othe beaker. Click on thegreen Zoom Out arrow to return t othe laborator y . 5.   Drag the beaker to the 50mL graduated c y l i nder (thelargest one) by the sink and e m ptythe sa m ple into the c y linder.  Hold thec y l i nder under the tap unt i l it fills withwater to m a k e an aqueous solution of NaHC O 3 . (When the graduated c y linder is full it will auto m at i ca l ly snap back into place.) Note that the solid is added and dissolved before the volu m e ismeasured when m aking a m ol ar solution. Che m ists normallyuse a volu m etric flask for m aking m o l ar solutions, but t his is not available in the s i m ulation. 6.   Determine the liters of solution i nthe c ylinder and r ecord the da t a in thedata t able. 7.   Determine the moles of NaHCO 3 in the sample and r e cord the datain the da t a table. Data T a ble ma s s N a HC O 3 m o l es N aH C O 3 liters solution 8.   The m olarityis calcula t ed using the fo r m u l a: mass solute molarity = =                   molarmasssolute moles solute L solution L solution 67 Virtual ChemLab: General Chemistry, Student Lab Manual/Workbook, v4.5 , Third Edition, by Brian F. Woodfield and Matthew C. Asplund. Published by Prentice Hall. Copyright © 2013 by Pearson Education, Inc. Rea c tionsandS t oichiom e t r y Calculate  the molarity of t h e NaHCO 3 solution  inun i ts of mol/ L . .

1. 2-13:
Creating
a
Solut
i
on
of
Known
Molarity
In this assignment,
y
o
u will weigh out asa
m
p
le of baking soda (NaHC
O
3
) and create a solution ofknown
m
o
l
arit
y
.
1.
Start
VirtualChemLab,
select
Reactions and Stoichiometry,
and then select

2. Creating aSolut
i
on of Known
M
o
larity
from
t
he list of assig
n
m
ents.The lab will open in the Ti
t
ration laborato
r
y
.
2.
In the labora
t
o
r
y
, a bot
t
le of baking soda (sodiumbicarbonate, NaHCO
3
) will be next to thebalance, and an e
m
ptybeaker will be on the stir plate. Drag the e
m
ptybeaker to the spot
l
ight next

3. t
o
t
h
e balance, clickin the
Ba
l
an
c
e
area to zoomin, place aweigh paper on the balan
c
e, and tare the
balance.
3.
Open the bot
t
le by clicking on the l
i
d (
Remove Li
d
). Pick up the
S
c
oo
p
and scoop out so
m
e sa
m
ple by first dragging the scoop tothe
m
outh of the bottle and then pull

4. i
ngthe scoop down the face of the
bottle. As the scoop is dragged down
t
h
e face of the bottle it will p
i
ckup different quantities ofsolid. Select the largest sa
m
ple possible and d
r
ag the scoop
t
othe weighing paper on
th
e balance until it
snaps in place and then let go. This will put app
r
oximately1 gofsa
m
ple on the balance. Repeat
with a second
Scoop
. Record the
m
a
ss of the NaHCO
3
in the data table.
4.
Drag the we
i
gh paper to the beaker and add the NaHC

5. O
3
sa
m
p
le
t
othe beaker. Click on thegreen
Zoom
Out
arrow to return
t
othe laborator
y
.
5.
Drag the beaker to the 50mL graduated c
y
l
i
nder (thelargest one) by the sink and e
m
ptythe sa
m
ple
into the
c
y
linder. Hold thec
y
l
i
nder under the tap unt

6. i
l it fills withwater to
m
a
k
e an aqueous solution
of NaHC
O
3
. (When the graduated c
y
linder is full it will auto
m
at
i
ca
l
ly snap back into place.) Note that the solid is added and
dissolved before the volu
m
e ismeasured when
m
aking a
m
ol
ar solution.
Che
m
ists normallyuse a volu
m
etric flask for
m
aking
m
o
l

7. ar solutions, but
t
his is not available in the s
i
m
ulation.
6.
Determine the liters of solution
i
nthe
c
ylinder and
r
ecord the da
t
a in thedata
t
able.
7.
Determine the moles of NaHCO
3
in
the sample and r
e
cord the datain the da
t
a table.
Data
T

8. a
ble
ma
s
s N
a
HC
O
3
m
o
l
es
N
aH
C
O
3
liters solution
8.
The
m
olarityis calcula
t
ed using the fo
r
m
u

9. l
a:
mass
solute
molarity
=
=
molarmasssolute
moles
solute
L
solution
L
solution
67
Virtual ChemLab: General Chemistry, Student Lab
Manual/Workbook, v4.5
, Third Edition, by Brian F. Woodfield and Matthew C.

10. Asplund. Published by Prentice Hall.
Copyright © 2013 by Pearson Education, Inc.
Rea
c
tionsandS
t
oichiom
e
t
r
y
Calculate
the molarity of
t
h
e NaHCO
3
solution
inun
i
ts of mol/
L
.