today is monday, february (!) 2 nd, 2015 pre-class: name one piece of lab equipment you know and its...

Today is Monday,February (!) 2nd, 2015

Pre-Class:Name one piece of lab equipment

you know and its purpose.

In This Lesson:Lab Equipment(Lesson 2 of 2)

Today’s Agenda

• Lab equipment introduction and inventory.– (let me know if anything’s missing or broken)

• Bunsen Burner practice.– That’s right, all you pyromaniacs out there!

Beaker

• Beakers hold solids or liquids that will not release gases when reacted or are unlikely to splatter if stirred or heated.– 100 mL– 250 mL– 400 mL

Erlenmeyer Flask

• Erlenmeyer flasks hold solids or liquids that may release gases during a reaction or that are likely to splatter if stirred or heated.– 250 mL

Florence Flask

• Rarely used in first year chemistry, it is used for the mixing of chemicals. Narrow neck prevents splash exposure.– Not in your drawer.

Graduated Cylinder

• A graduated cylinder is used to measure volumes of liquids.

• A meniscus will occur for many liquids. Measure to the bottom of the curve.– 10 mL– 50 mL– 100 mL

Test Tubes (not in your drawer)13 x 100 mm test tubes

10 x 75 mm test tubes

Ignitiontube

Test Tube Racks

Test Tube Holder

• A test tube holder is useful for holding a test tube which is too hot to handle.

Test Tube Brushes

• Test tube brushes are used to clean test tubes and graduated cylinders.

• Forcing a large brush into a small test tube will often break the tube.– One large, one small

at your station.

Rubber Stoppers

• Rubber stoppers are used to close containers to avoid spillage or contamination.

• Containers should never be heated when there is a stopper in place.– Not at your station.

Watch Glass

• A watch glass is used to hold a small amount of solid, such as the product of a reaction.– Not at your station.

Glass Stirring Rod

• A glass rod is used to manually stir solutions. It can also be used to transfer a single drop of a solution.

Eye (or Medicine) Dropper

On top of each medicine dropper is a “rubber bulb.”Let’s try practicing proper eyedropper technique!

Forceps

• Forceps (or tweezers) are used to pick up small objects.– Not at your station.

Funnel

• A funnel is used to aid in the transfer of liquid from one vessel to another.

Wash Bottle

• A wash bottle has a spout that delivers a wash solution to a specific area. Distilled water is the only liquid that should be used in a wash bottle.– Not at your station.

Weigh Boat

• Weighing boats are used to weigh solids that will be transferred to another vessel.– Not at your

station.

Spatula

• Spatulas are used to dispense solid chemicals from their containers.

• Chemicals should never be transferred with your bare hands.– You have a similar piece

of equipment known as a “scoopula” or “scoop.”

Beaker Tongs

• Beaker tongs are used to move beakers containing hot liquids.

• Beaker tongs have rubberized (or plastic-y) ends for gripping beakers.

Crucible Tongs

• For handling hot crucibles; also used to pick up other hot objects.

• NOT to be used for picking up beakers!

Clay Triangle

• The clay triangle is used as a support for porcelain crucibles when being heated over a Bunsen burner.

Ring Stands and Their Components

• Ring stands are a safe and convenient way to perform reactions that require heating using a Bunsen burner.

• Don’t slide them on the lab table or they make a sound no human should ever hear.

Ring Stands and Their ComponentsIron Rings

• Iron rings connect to a ring stand and provide a stable, elevated platform for the reaction.

• If you like your ring stand, you should put a ring on it.

Ring Stands and Their ComponentsUtility Clamps

• Utility clamps are used to secure test tubes, distillation columns, and burets to the ring stand.

Ring Stands and Their ComponentsWire Mesh

• Wire mesh sits on the iron ring to provide a place to stand a beaker.

• On older wire mesh, the white material is asbestos!

Ring Stands and Their ComponentsDouble Buret Clamps

• Double Buret Clamps are used for burets – long graduated tubes used in titration.– Not at your station.

Striker

• Strikers are used to light Bunsen burners.

• The flints on strikers are expensive. Do not operate the striker repeatedly just to see the sparks!

Safety Glasses and Equipment

• Found in the cabinet by the big sink.• YOU MUST WEAR THESE UNLESS TOLD

OTHERWISE. FOR REALS.• Also take note of the emergency shower and

eyewash station.• Get some safety glasses now, by the way.

Bunsen Burner

• Bunsen burners are used for the heating of nonvolatile liquids and solids.

• [See demonstration]• “Plug in” the burner.• Hold the striker upside down above the burner.• Turn the gas on (valve should be even with the nozzle).• Strike and pull your hand away.– Lighting your hand on fire is not part of this.

• IMPORTANT:– Adjust the upper collar (air) for flame temperature.– Adjust the lower gear (gas) for flame height.

Lighting the Bunsen Burner

http://ch185.semo.edu/labsafe/bunsen.html

Bunsen Burner Flames

http://ch185.semo.edu/labsafe/bunsen2.html

Bunsen Burner Flames

http://www.mr-damon.com/experiments/bunsen/

Bunsen Burner Flames

• Safety Flame (300 °C)• 572 °F

• Medium Flame (500 °C)• 932 °F

• Roaring Blue Flame (700 °C)• 1292 °F

Crucible

• Crucibles are used for heating certain solids, particularly metals, to very high temperatures.– Not at your station.

Evaporating Dish

• The evaporating dish is used for the heating of stable solid compounds and elements.– Not at your station.

Mohr Pipet

• A Mohr pipet measures and delivers exact volumes of liquids.– Not at your

station.

Glass Plates

• Glass plates provide a surface for semi-micro scale experiments, such as drop reactions and testing of acids and bases.– Not at your station.

Triangular File

• Triangular files are used primarily to cut glass rod, a skill that your instructor will share with you when it becomes useful.– Not at your station.

Gas Collecting Bottle

• We use gas collecting bottles when large volumes of gases are produced, and must be collected by the displacement of water.– Not at your station.

Pressed Fiber Pad

• A 4” x 4” square of ceramic fiber, it provides a surface for hot beakers so that the beaker does not come in contact with a cold countertop and shatter.– Not at your station.

Litmus Paper

• Red litmus paper is used to identify bases.

• Blue litmus paper is used to identify acids.– Not at your

station.

Electronic Balance

http://static.coleparmer.com/large_images/1101050.jpg

• Measures mass (who knew?).• Take a moment to practice – measure out 18

grams of water (or as close as you can) in a 250 mL beaker.– Remember to use the Zero button!

Practice Lab Setup

• Using the materials in your lab station, setup your equipment and boil water. Keep the setup low!

• Materials needed:– Ring Stand– Ring– Wire Mesh– Beaker– Thermo-gloves

http://icn2.umeche.maine.edu/newnav/newnavigator/images/P7210103.JPG