an introduction to laboratory equipment. a chemist in any line of work, a professional is expected...
TRANSCRIPT
AN INTRODUCTION TO LABORATORY
EQUIPMENT
A CHEMIST
In any line of work, a professional is expected to know and understand how to use his or her “tools of the trade;” things are no different in a chemistry lab. This presentation will introduce you to the lab equipment you may be using during the duration of this course.
Without a doubt … THE MOST IMPORTANT PIECE OF “EQUIPMENT” YOU’LL USE IN LAB…
Safety Glasses…continued
They must have clear lenses and meet the ANSI Z87.1 standard which can be identified by the Z87.1 on the package label or embossed on the temple eye piece.
You are to wear your safety glass over your eyes; not on your head nor around your neck
Beaker
BEAKER…continued
Beakers, this type is formally called a Griffin beaker…
They are used for the containing, mixing, or transferring of chemicals.
They are NOT accurate; not used to measure
Bunsen Burner
Bunsen Burner…continued
•Care must be used properly; know how to use the gas valve; needle valve and air port
•Flame color indicates how hot the flame is
•Should not be used when flammable vapors are present; use a hot plate instead
WIRE GAUZE WIRE GAUZE can be used
to support a container (such as a beaker or flask) during heating. When the Bunsen burner flame is beneath it, the wire gauze helps to spread the flame (and heat) out evenly over the container.
Hot Plate
* Variable heat control but the settings are relative and not exact temperatures
* No open flame; safe when using volatile liquids
that are flammable
Beaker Tongs
BEAKER TONGS…continued
Used in removing a beaker from a heat source, such as, a Bunsen Burner or Hot Plate.
Be careful not to touch the flame or heated surface with the rubber coated portion- it will stink
Ring Stand
Ring Stand…ContinuedUsed for attaching a variety of
clampsThere are several different formsA solid white base one is used for
titrations (a procedure for adding small precise amounts of one solution to another watching for a color change)
Can use a white sheet of paper with a standard base
CLAMPS
Utility (Left)
Universal (Above)
Clamps…continued
Ring clamp (Right)
Buret clamp (Left)
Clamps…continuedUsed primarily to attach and hold
glassware and other laboratory equipment
Some examples are as follows* Distillation set-ups* Titration set-ups* Filtration set-ups* Heating crucibles
See the following pages
Distillation Set-up…
The condenser (shown)- changes vapor back to a liquid by absorbing heat energy from the gas
FANCY DISTILLATION SET-UP
Titration set-up…
Filtration set-up
Heating Crucible set-up…
Buret
Detail of stopcock (Above)
BURET A buret is an open ended tube with volume gradations on it. The other end has a stopcock which allows the chemist to regulate the flow thereby delivering a solution in precisely-measured, variable volumes. Burets are used primarily for titration, a procedure to deliver one reactant until the precise end point of the reaction is reached.
ERLENMEYER FLASKThese flasks are typically used to mix chemicals
and/or solutions … also not used
for accuracy!
FLASKS…Erlenmeyer
FLASKS…ErlenmeyerIdeal for mixing liquids or dissolving solids as the conical shape keeps liquids from splashing outside the glassware
Are NOT used to make solutions of a desired concentration as the gradations are merely estimates
FLASKS…Florence
FLASKS…Florence
FLASKS…Florence
Primarily used to heat solutions as its rounded bottom creates a more uniform heating surface than does a beaker or Erlenmeyer flask
Can be used for mixing solutions or dissolving solids
FLASKS…Volumetric
FLASKS…Volumetric…Continued
Close-up view of a volumetric flask used to make 100mL of solution of a known concentration
FLASKS…Volumetric
Used to prepare solutions of a given volume; consequently the volumetric flask can ONLY be used for its specified volume
These are extremely precise and are used in analytical laboratory work
FLASKS…Boiling
Almost identical to a Florence flask except that its bottom is rounded, not flat.
Requires a special cork ring holder on counter surface
Potential spill hazard as well as glass breakage
FLASKS…Filtration
FLASKS…Filtration When attached to an aspirator
via the nipple on the side of the flask, a vacuum suction is created that will increase filtering time
Aspirator on left
Graduated Cylinder
Graduated Cylinder…continued
Tall cylinder with a range of calibrated markings (gradations) used for measuring the volumes of liquids in milliliter (mL)
TEST TUBES
A tube of glass, closed at one end, used to
contain chemicals
during heating or other
reactions.
Test Tube Rack
Test Tube Rack…continued
Holds test tubes when not in use
Wooden racks are prone to tipping over therefore the metal ones are preferred
Can be used to hold test tubes while drying
Test Tube Clamp
Holds test tube while heating in a burner flame; do not confuse with utility clamp
TEST TUBE BRUSH
Used to clean test
tubes
SPATULA
Two types shown: Used when obtaining dry chemicals from a stock container
CRUCIBLE and LID
Crucible and Lid…Continued
Used when heating substances to very high temperatures...Caution it gets very hot and will cause a severe burn if handled improperly
Crucible Tongs
Curved tips are key identifier.. See next slide
Crucible Tongs…Continued
Used to carry crucible as well as lift crucible lid off
EVAPORATING DISHUsed for heating … usually when you want to evaporate a liquid from a solution.
WATCH GLASSTypically used as
a “beaker cover,” but can also be used to evaporate the liquid from a solution.
Can be used to extinguish small fires inside a beaker
Clay Triangle
Clay Triangle…Continued
Used to support a crucible when the ring clamp is too large
Clay Triangle…Continued
Can hold a funnel if the ring clamp diameter is too large; use your
imagination here
Pipettes (also spelled “pipet”)
Volumetric Pipette- dispenses a specific volume as specified on pipette
Measuring Pipette- dispenses measured volumes according to calibrated gradations on pipette
Dropping Pipette- used to transfer liquids or add drop by drop without regard for the volume
Pipette Pump
Used instead of sucking with our mouths on pipettes; Color coded to the volume of the pipette- must use the correct one for proper suction
BALANCES
Electronic Balance – For “weighing”
Balances…Continued
Harvard Pan Balance – Compares the known mass of “weights” to that of the substance being weighed
Wash Bottle
Wash Bottle…Continued
*Used to wash residue out of beakers and test tubes for analysis procedures*Wet filter paper *Wash a titrated solution into Erlenmeyer Flask
Mortar and PestleMortar (on far left) and Pestle (on immediate left)
* Use a grinding motion not pounding
*The idea is to catch the solid between the head of the pestle and wall of the mortar thereby crushing the solid into smaller particles
FUNNEL
Used in filtration- the separation of an insoluble substance from a liquid
SEPARATORY FUNNEL
*Tear-drop shaped with a ground-glass stopper at the top and a stopcock at the bottom
*Used to separate two immiscible liquids, that is two liquids that are insoluble in one another
*You draw off the lower liquid first stopping just before the boundary layer (the interface), set it aside, pour off the boundary layer plus a little of the top layer to avoid contamination, then pour the top liquid into a clean beaker or flask
FORCEPS
*Used to remove filter paper from a funnel without contaminating it
*Use to handle hot materials or those substances that may be a skin irritant