It is this property of glass which makes glass working possible and, as such, allows for an incredible variety of lab ware. “Soft” soda-lime glassware is not heat-resistant because it has a low melting point (600-800 °C) and a high coefficient of expansion; when it is suddenly subjected to extreme temperature changes, it will break or crack.
However, it can be used for such equipment as volumetric flasks, glass tubing, stirring rods, graduated cylinders etc. “Hard” high-temperature-melting (750-1100 °C), heat-resistant borosilicate laboratory glassware (Pyrex or WIMAX brand glassware, for example) is used wherever sudden changes in temperature may occur, e.g., beakers or Erlenmeyer flasks which may suddenly be chilled, round-bottomed flasks, distillation columns and condensers -- in fact, just about everything in your equipment drawer.
This kind of glassware may be subjected to direct high heat, and can be worked only with an oxygen torch. If not, it may be available at the Chemistry Stockroom window if needed, and CS personnel will be happy to demonstrate the proper method of working with glass tubing.
Only make one single, straight cut with a smooth movement of the hand. Once the tubing (or thermometer) is snugly inside the stopper, it's not a good idea to try to remove it after use.
Pieces of glass tubing (and sometimes thermometers) are frequently inserted through rubber stoppers. This procedure, while seemingly a simple one, is responsible for a majority of student injuries incurred in the Chem labs.
The first number indicates the approximate diameter of the larger tube in millimeters; the second indicates the length of the ground surface. Ground-Glass Joint glassware is precision-ground to a specific taper, and this allows the snug fit when two corresponding pieces are joined.
Dust, dirt, chemical residue, and/or particulate matter may score the surface and cause leakage. It is kept in a small jar near the instructor's station in the teaching lab, with the rest of the stock reagents and supplies.
Note that the grease is hydrocarbon (petrolatum) based, and therefore is soluble in most organic solvents. This means that you will need to re-apply fresh grease every time you carry out a reaction, since it may dissolve somewhat during use.
Use a boiling stick to apply a small amount of grease to the upper part of the inner joint, taking care not to grease any part of the joint which may come in contact with vapor or liquid and cause contamination. A properly lubricated joint appears completely transparent, with no striations.
Use a boiling stick to apply two circular bands of grease around the stopcock, midway between the bore and the ends. Insert the stopcock into the barrel (of the separator funnel) and twist several times.
If this happens, come to the Chemistry Stockroom window and request a pipe cleaner to unplug the bore or ask Dan to help. The grease is hydrocarbon-based, so it is soluble in most of the organic solvents stocked in the teaching lab rooms.
Similarly, take apart (glass) stopcocks and store the piece assembled. It also helps to prevent glassware breakage, and therefore might save you from having to pay for a few costly items.
Plan your assembly so the working area will be uncluttered, with easy access to all components. Laboratory distillation glassware, separator funnels, and reagent bottles with glass-to-glass connections sometimes become “frozen,” or stuck.
To loosen stopcocks, stoppers, or ground-glass joints, you may use the following techniques at your own risk. If you would rather not attempt any of the following procedures, simply bring your frozen joint to the Chemistry Stockroom window and request that CS personnel assist you.
Always work directly over a bench top covered with soft cushioning material to prevent the falling stopper from breaking. Repeat several times, allowing the housing to expand and contract to break the frozen seal.
Washing and Cleaning Lab Glassware Most pieces of lab glassware can be cleaned by washing and brushing with a detergent or with a special laboratory cleaning product called Alcohol (the “SOAP” jugs in the lab rooms next to the sinks contain a dilute Alcohol and/or dish soap solution). If dirty glassware cannot be washed immediately, put it in water to soak.
Handle glassware carefully when cleaning it, as the soap and water will make it slippery. Be sure to rinse off all soap or detergent residue after washing glassware to prevent any possible contamination later.
Another method of drying glassware is to use the dryer oven located in the organic lab. Sometimes the residue on your glassware won't come clean with just soap and water and scrubbing, although most of the time it will.
The following tips should cover most of the eventualities you will encounter in the Chem teaching labs: Stopcock grease and most oily residues are usually soluble in petroleum ether (either high-boiling or low-boiling) or humane.
Although inorganic in nature, these stains are difficult to remove with just soap and water. A dilute aqueous solution of italic acid (available from the OCS window on request), however, is guaranteed to remove the residue.
If you really, really can't get a stain or residue off your glassware, we may allow you to exchange it for a clean piece. Handling Broken Glass Broken lab glassware, in addition to having sharp and jagged edges which can cause serious injury, you also have the added element of danger in that there is most likely chemical residue on the glass itself.
Cutting yourself on a piece of broken glass with chemical residue on it could seriously mess things up, especially in an organic chemistry lab. So if you have broken a piece of glassware holding any chemicals--a reaction, or simply a reagent waiting to be used --alert your instructor and/or TA.
Your instructor will advise you in the proper method of cleaning up a chemical spill. Discard them in the white cardboard box marked “BROKEN GLASS” in the lab.
Please do not carry a piece of broken glassware down the hallway to show the Chemistry Stockroom. Only place it in the Glass Trash, and do not carry it down the hallway to show the CS.
Knowing the proper use will help ensure safe laboratory practices. Bunsen Burner Frequently used as a heat source in the absence of flammable materials.
Crucible Used for holding chemicals during heating to very high temperatures. Funnel Used to transfer liquids or fine-grained materials into containers with small openings.
Graduated Cylinder Used to measure a precise volume of a liquid. Ring Stand Used to hold or clamp laboratory glassware and other equipment in place, so it does not fall down or come apart.
Thermometer (digital or alcohol, not mercury) Used to measure temperature in Celsius. Utility Clamp Used to secure glassware to a ring stand.
Volumetric Pipe Used to measure small amounts of liquid very accurately. Wash Bottle Used to rinse pieces of glassware and to add small quantities of water.
Watch Glass Used to hold solids while they are being weighed or to cover a beaker. Wire Gauze Used to support a container, such as a beaker, on a ring stand while it is being heated.
From tumblers to champagne flutes, glassware is used to serve water, cocktails, beer, liquor, wine, coffee, tea and other beverages. Alcoholic drinks are often served in specific types of glassware.
Dance highball glass : A blue glass used to serve a variety of mixed drinks, like the screwdriver, piña colada and Long Island iced tea. Earline highball glass : Available in azure light blue, amethyst purple, dark ruby red, cobalt blue and emerald green hand-cut glasses.
Marsala Collins glass excelsior : Available in six colors and used to serve alcoholic drinks. Stemware is a type of glassware that sits on a base and is typically used for formal family gatherings and holidays; the most well-known is the wine glass.
Red wine is typically served in stemware that has a wide, open bowl, and white wine is served in stemware with a narrower bowl. Common types of glassware include beakers, flasks, pipettes, and test tubes.
Magi Studio / Getty Images Beakers are the workhorse glassware of any chemistry lab. The spout makes it easy to pour liquids into other containers.
Finally, the wide opening makes it easy to add materials to the beaker. Bogdan Drama / Eye / Getty Images There are multiple types of flasks.
For some situations, either a beaker or an Erlenmeyer flask is a good choice, but if you need to seal a container, it's much easier to put a stopper in an Erlenmeyer flask or cover it with para film than it is to cover a beaker. Stuart Money / Getty Images Test tubes are good for collecting and holding small samples.
Thanakorn Srabubpha / Eye / Getty Images Pipettes are used to deliver small volumes of liquids reliably and repeatedly. This type of glassware isn't intended to be exposed to flames or extreme temperatures.
Pipettes can be deformed by heat and lose their measurement accuracy under extreme temperatures. It's almost always made of borosilicate glass so that it can withstand heating under a direct flame.
ElementalImaging / Getty Images Volumetric flasks are used to prepare solutions. Each features a narrow neck with a marking, usually for a single precise volume.
Because temperature changes cause materials, including glass, to expand or shrink, volumetric flasks aren't meant for heating. These flasks can be stoppered or sealed so that evaporation won't change the concentration of a stored solution.