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…Continued Used for attaching a variety of clamps There are several different forms A 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…continued Used 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

F ANCY DISTILLATION S ET - 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 FLASK These flasks are typically used to mix chemicals and/or solutions … also not used for accuracy!

FLASKS… Erlenmeyer

Ideal 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

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

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)

T EST T UBES 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 DISH Used for heating … usually when you want to evaporate a liquid from a solution.

WATCH GLASS Typically 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 Pestle Mortar (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