HOW TO Prepare titration in pysics/chemistry pratical

As 2013 WAEC May/Juneand
2013 NECO June/July are
approaching, we at
dollaplaza team have
decided to
expose students to information
that will make them
have better grades in their exam
We want to share a Titration
Guide we culledfrom
Wikihow.com to help 2013 WAEC
May/June candidates
learn about how to prepare a
simple titration.
What is Titration? A titration is a
technique used in chemistry to
help
determine the concentration of a
reactant mixed in
with an unknown.
When done correctly and
carefully,
a titration will yield veryprecise
results. Here is how
to perform one.
Steps/ Guides
1: Obtain the items listedin' the
Things You
Need in section below.
2: Rinse and purge your burette.
3: Clean and rinse all glassware
with tap water (DI H2O
if available is better), using some
detergent if
necessary. Be very careful with
burets, as they are very fragile.
Always hold them with two
hands.
4: Rinse all glassware with
distilled water to lower the
chances of contamination.
5: Measure out a preciseamount
of analyte (the
reactant mixed in with the
unknown).
6: Fill your beaker or Erlenmeyer
flask with a small amount of
distilled water.
7: Rinse the analyte into your
beaker or Erlenmeyer
flask, thus making sure all of the
analyte is in the
beaker.
8: Put a small amount (4-5
drops) of the appropriate
color indicator into the beaker.
9: Agitate the beaker s contents
by swirling the
beaker.
10: Fill the burette with an
excess amount of titrant
(chemical that reacts with the
analyte). The titrant
should be in an aqueousform.
11:Clamp the burette carefully to
a burette stand. The tip of the
burette should not be touching
any surfaces.
12 : Place the beaker under the
burette.
13: Record the initial volume of
the burette atthe
meniscus (the lowest part of the
dip in the liquid).
14: Turn the stopcock ofthe
burette (valve near the
tip) vertical, so that titrant is
added to the beaker.
Only let a small amount of the
titrant out. A colorchange
should occur. Agitate thebeaker
until the color
disappears.
15: Repeat the above step until
the color persists
slightly (you may barely notice it,
so be careful &go
extremely slowly).
16 : Record the volume of the
burette.
17: Add titrant drop by drop as
you near the endpoint.
18 :Agitate the beaker contents
after every drop.
19: Stop when you ve reached
endpoint, which is the
point when the reactant within
the analyte has been
completely neutralized. You can
tell you ve reached the endpoint
with a colour change, depending
on
which indicator you chosen to
use.
20: Record your final volume.
21: Past endpoint point of no
return. Add drops of
titrant until you pass endpoint.
At this point, the
beaker s contents should be
entirely the color of the color
indicator when titrant is added.
22: Clean up by wiping away all
standing water.
23: Dispose of the chemicals
used in a labeled waste
container.
24: Calculate the concentration
of the reactant within
the analyte using the data
gathered.
Important Tips Have your eyes at
the same level while reading the
volume from the burette if your
eyes are at a diff
level each time your readings will
not be as accurate.
Record the volume of the burette
to one digit past
what is given (ex: buret has
readings to the nearest
tenth;
take your observation down to
the nearest
hundredth).
Calculations of the concentration
should be done to the
appropriate number of sig figs.
Tips for better accuracy:put a
small beaker over the top of the
burette,
especially if you are titrating with
NaOH; if it is left in
contact with the air someof the
OH will bond w/
water molecules and it will
disturb the molarity of the NaOH
solution.
Endpoint is extremely easy to
overshoot, if you re
not careful and observant.
When you have the
slightest feeling you' re
approaching end point, start
counting drops, and go
extremely slowly.
keep a watchglass over the
flasks of water & the
unknown; the time they are left
sitting out while you are doing
your other titrations can change
the
molarity.
Handle the burette with care
they are easily broken.
Remember to take out the filter
funnel after you have
done filling the burette with the
titrant as it can
prevent your titration from being
perfectly accurate.
Precaution
Be sure to rinse all of the analyte
into the beaker.
Any
left in the weighing boat/
container will result in
mis calculations. Dont rinse any
of the chemicals
down the sink; put into an
appropriate, labeled waste
container.