VOLUME MEASUREMENTS Flashcards
are used for measuring
small volumes of liquid.
Pipets
TD
to deliver
This indicates that the
measurement of this
graduate will compensate
for the excess liquid that
adheres to the surface of
the graduate after
emptying.
“TD” - “to deliver”
TC
to contain
This indicates an accurate measurement of
volume but pouring into another container
will not necessarily deliver the indicated
volume.
“TC” - “to contain”
Reading must be done
at eye level To prevent
parallax error
convex meniscus is for
colored
concave meniscus is for
clear
The mark at the bottom
of the meniscus for
colorless liquids
At the top of the
meniscus for
colored
liquids
Analytical procedures require
accuracy and precision
Using at all times glasswares that are
clean
All _____ glassware that is used in
precise measuring of liquids should
have fully _____.
class A
wettable surfaces
Good cleaning practices should also be
accompanied by good _____ of the glass
surfaces for chips, cracks, or abrasions which
will cause mechanical failure.
inspection
Cleaning the burette
Make sure the _____ is in
close position
stopcock
Add a few milliliters of
_____, then tip
and roll the burette to allow
the detergent solution to
have contact with all the
inner surfaces
detergent solution
Open the stopcock and
allow the detergent
solution to _____.
drain
Repeat step 1 using
tap water to rinse off
the detergent
solution, then wash
_____ with
distilled water
three times
After draining the distilled
water, close the stopcock
and add about ____ of the
solution to be dispensed
from the burette
5 mL
MICROPIPETTE Procedures
- Place a fresh tip securely
on the barrel, carefully
avoiding direct contact
with the tip - Set the knob at the top
of the pipet to the
desired volume. - Depress the plunger to
the first stop to dispense
the selected volume. - Hold the pipet in an
upright position,
immerse it 3-5mm into
the reagent solution,
and slowly release the
plunger to suck up
liquid. - Withdraw the pipet tip
from the liquid by sliding
it along the container wall
to remove liquid from the
outside of the tip. - Lean the micropipette tip to the wall of
the receiver and gently depress the
plunger to the first stop to dispense the
liquid. - Allow the liquid to drain along the wall of
the pipette tip, then depress the plunger
farther to squirt out the last liquid. - Discard the tip.
Used for transferring liquid to another
container or to transfer a small amount of
reagent for use in procedures.
Beaker
They are generally
more accurate and
precise for this
purpose than flasks.
Graduated Cylinder
This is a semi-
accurate liquid
measuring vessels
Graduated Cylinder
Used for measuring
small volumes of
liquid
Pipettes
This will dispense
that exact volume
indicated
TD Pipette
This holds or contains a particular volume
but does not dispense that exact volume.
TC Pipette
This has a continuous etched ring, or two
small, close continuous rings located near
the top of the pipet
Blowout Pipette
- To contain or deliver
specific volumes of liquid
sample - Used in preparing
solutions of accurately
known concentrations
Volumetric Flask
are not
used for storage of
solutions
Volumetric Flask
A long, narrow tube
with a stopcock at its
base.
Burette
It is used for accurately
dispensing flexible
volumes of liquids or
solutions.
Burette
The procedure
of adjusting or
standardizing
equipment
before use.
Calibration
