what is the proper technique to: smell a chemical, dispose of waste, heat a test tube, chemical storage?

Answer 1

Proper way to smell a chemical is to waft your hand above the container towards your face. Never smell or sniff a chemical straight on with your nose... hazardous chemicals can burn your nose and lungs. So just waft the air up towards your face to smell a chemical.

Hazardous waste disposal
Under no circumstance is any person to dispose of a hazardous substance down the
drain or in the trash. Waste chemicals should be collected in separate containers by
categories segregated such that spills or leaks would remain isolated from other
containers of wastes or chemicals. These categories include but are not necessarily
limited to:
1. Acids
2. Bases
3. Solids
4. Halogenated solvents
5. Non-Halogenated solvents
6. Mercury wastes
7. Reactive chemicals wastes with high heavy metal contamination

To heat a test tube you use tongs to hold the test tube over the source of heat. Never point the open end of the test tube towards you or any one else. Never look into the containter as it is being heated. Allow the glass to cool in a rack before handling. Use tongs or heat-resistant gloves. Don't sit the hot tube on lab surfaces. The glass can remain hot for a long time.

Chemical storage- 1. Do not store excessive quantities of chemicals in research laboratory.
Purchase the minimum amount required and disposes of unneeded chemicals
in a timely fashion.
2. Date bottles of chemicals when they are opened. Peroxidizable chemicals such
as isopropyl ether should be tested periodically or discarded according to the
time limits. Discard any chemical of dubious purity (by the usual waste
disposal procedures) if it cannot be purified safely.
3. Store reagents on shelves or in cabinets. Store large bottles of chemicals on
the lowest shelves of any chemical storage area. Do not allow bottles to
extend over the edge of a shelf.
4. Do not store chemicals on bench tops. They are more readily knocked over
and are unprotected from potential exposure to fire.
5. Hoods should not be used for chemical storage. Hood storage interferes with
air flow in the hood, causes clutter, and increases the fuel load in the event of
a hood fire. If small quantities of chemicals are stored in the hood, they should
be placed on an elevated shelf.
6. No chemicals (either reagents or waste chemicals) should be stored on the
floor. Floor storage presents a major safety hazard because bottles can break if
knocked over or struck together.
7. Chemicals requiring refrigerated storage should be properly labeled and
sealed to prevent escape of any vapors. Use only refrigerators designated for
chemical storage. Flammable liquids MUST be stored only in explosion-safe
refrigerators. Do not refrigerate chemicals unnecessarily.
8. Seal caps of open bottles of volatile chemicals using Parafilm. This will
prevent odor problems and deterioration of air/moisture sensitive reagents.
9. Inspect storage areas periodically for damaged containers such as cracked
bottles or caps or rusted cans. Replace loose or deteriorating labels.
Laboratory Chemicals Storage
Laboratories are not storerooms. This applies to the storage of chemicals, solvents and
equipment. For success in chemicals storage, use these criteria.
1. Small amounts, not stockpiled.
2. Ordering the 1 kilogram (kg) size, because it is cheaper than the 100 gram size, is
often false economy in the long run. The result is:
a. It takes up more valuable space.
b. It presents a greater potential hazard.
c. It may eventually be a disposal problem.
3. Secured
a. Do not overcrowd shelves.
b. Do not store too high; provide a proper kick stool or ladder where
necessary.
c. Chain compressed gas cylinders.
d. Store lecture bottles upright and chain or secure in a proper holder.
e. Store solvents in a proper flammable liquids cabinet, and keep door closed.
f. Use appropriate containers for solvents and waste.
g. Store highly toxic or controlled materials in a secure or locked cupboard.
4. Labeled properly
a. Label contents clearly.
b. Labels must be intact and legible.
c. Do not overwrite labels.
d. Label solvent stills.
e. Label and regularly check peroxidizable materials (e.g. isopropyl ether).
5. Sealed
a. Keep solvent containers closed.
b. Ensure chemical containers are intact.
c. Ensure container lids are intact and closed.
d. Regularly vent materials capable of building up pressure; e.g. formic acid.
6. Segregated
a. Know what is in storage; separate incompatible materials.
b. Be aware of nomenclature problems (e.g. PHENOL is also known as:
carbolic acid; hydroxy benzene; oxybenzene; phenic acid; phenyl
hydroxide; phenylic acid or phenylic alcohol).
c. The Merck Index can be a useful reference for checking confusing or
equivalent names.

Answer 2

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Answer 3

Assuming your teacher has asked this question and wouldn't give a chemical that was unsafe to heat: a) wear your safety glasses and lab coat b) tie back any long hair, tuck in your tie etc. c) check your testube is pyrex and not soda d) heat on a clear flame (I'm assuming you will be using a Bunsen here!) while inclining the tube at a slight angle and point the open end away from your self and those around you. Hope that helps.

Answer 4

To smell a chemical you hold the sample up, away from your nose, and then you pass our hand over the sample pushing the fumes toward you. If the fumes are dangerous or noxious then this small sample won't harm you. If you can't smell anything then you get closer to the sample and waft the fumes toward your nose, you continue to do this until you smell the sample or determine it has no order. Chemical reactions that produce noxious fumes should be performed in a hood. A hood is a 3-walled container, shielded against most chemical reactions with a glass door on the open side. The hood has a fan and vent that forces the chemical fumes outside. If the reaction gets out of hand then the hood can be closed and the fumes vented. Of course if you are using something really hazardous then you will need filters and screens to contain the hazardous fumes.

There are proper means of disposing of chemical waste, and this is one of the first things that any lab will tell you. Pouring chemicals down the drain won't cut it. The possible chemical reactions could interact dangerously or even rupture or corrode the pipes. If you are doing the experiments at home then you need to find some company that is willing to accept your waste, before you start to experiment, and they will need to know your creation’s chemical components, your waste and any byproducts you might produce. Until then you will have to store it in a proper container. The container could be glass or metal depending on the chemicals involved. Usually glass is the more stable container though. Don’t use a jar with a metal lid; use something with a glass lid like a mason jar. Of course you still have to worry about the rubber seal, and might want to remove it first. There is no hard and fast rule of how to store chemicals, it depends on what they are and what reactions they can create. Red Phosphorus has to be stored in an airtight container, Sodium must be stored in a container that isolates it from water, most acids can be safely stored in glass containers, but rubber gaskets have to be considered. Normally the chemicals themselves are sold in stable containers so the original container is the best storage medium. The problem is with the waste and byproducts; the proper container depends on the possible reactions. Again glass is usually the most stable. The waste and the raw chemicals should be stored in a locked cabinet away from anything flammable, and in an area with a good airflow to prevent the chemical vapors from accumulating. The garage may not be the best place for this, but rather an outdoor shed, preferably one that is built out of concrete block. It doesn’t have to be a walk in blockhouse, just one the can hold your chemicals and any waste (max sure to vent it and filter or contain any hazardous wastes).

Never, never add water to an acid; always add the acid to water. Water and acids create an exothermic (heat producing) reaction that can rupture the container. I have seen a teacher trying to add water to acid; he had it in the hood, and was using a thick walled reagent bottle. Still the bottle cracked and he had to run to the sink or risk spilling the sulfuric acid all over the floor.

Heating a chemical sample or mix requires an evenly controlled flame like a Bunsen Burner or an alcohol lamp. The sample is heated slowly and evenly. It is best to not try and hold a test tube over a flame, instead use an experiment test stand with a ring to support the sample container. A metal screen will prevent the flame from directly contacting the actual container. This makes it easier to control the heat and stop the container or its contents from getting burned.

Never force a glass pipe through a rubber stopper; I have seen a person accidentally push the pipe through their own hand doing this. Always use glycerin to lubricate the stopper first. You don’t want to use a more complex chemical like a petrochemical that you would find in Vaseline, because it introduces more reaction possibilities if your chemicals should escape.

You will want to conduct your experiments on a stable workbench like a granite or marble bench.

Just what precautions you have to take depend on the chemicals and the wastes involved. Most home lab kits are pretty safe chemicals and they should come with instructions on how to handle the chemicals and the resulting waste. If you use mercury then you must avoid touching it or breathing in its fumes. Iron filings and baking soda are pretty safe. You can buy ammonia over and bleach over the counter, but if you add chlorine then you will get chlorine gas; one of the most hazardous chemicals you can deal with. You can buy Hydrogen Peroxide over the counter as well, but it is in very diluted quantities; not enough to make explosives or to fuel your own jetpack. You can make nitroglycerin or nitrocellos at home as well, but any error in temperature control can cause it to explode. Then there are state and local laws you have to consider. In California you need a license to explode black gunpowder. Several counties require a license to store or transport hazardous waste.

For the home experimenter the best rule is KISS (keep it simple silly). For more complicated experiments you need to perform them in a lab. For the professional inventor, I still recommend some lab time to learn the proper procedures and practices.

A good cheap resource for your own chemical experiment equipment and some other gear is American Scientific Surplus: http://www.sciplus.com/ Since it is surplus it is cheap, and you never know just what they have in stock until you visit their website.

Answer 5

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(A) MAKE SURE YOU KNOW WHAT COMPOUND YOU ARE DEALING WITH. IF YOU ARE NOT SURE PLEASE READ MSDS (MATERIAL SAFETY DATA SHEET ). THESE ARE EITHER SUPPLIED WITH THE COMPOUNDS OR ARE AVAILABLE IN LAB. ASK FOR IT IF YOU DO NOT KNOW. THEY ARE AVAILABLE ON LINE ALSO. NEVER TRY TO HEAT ANY COMPOUND IF YOU DO NOT KNOW. (B) SECONDLY, IF THE COMPOUND IS " UNKNOWN" PROCEED WITH UTMOST CARE. (C) WEAR SAFETY GOGGLE, (D) HEAT THE COMPOUND VERY VERY SLOWLY. (E) KEEP TEST TUBE AWAY FROM YOURSELF. (F) MAKE ALL THE OBSERVATION AND WRITE THEM DOWN IN AS MUCH DETAILS AS YOU CAN. (G) SUCH AS THE COMPOUND EITHER MELTS FIRST OR DOES IT SUBLIME OR IT BURNS IMMEDIATELY OR DOES IT DEPOSIT ON COOLER PARTS OF TUBE ETC ETC. GOOD LUCK. BEAR IN MIND " SAFETY IS NUMBER ONE IN A CHEMICAL LAB." BECAUSE SOME COMPOUNDS ARE VERY EXPLOSIVE AND WE DO NOT NEED ANY ACCIDENTS. I HOPE THIS WILL HELP. [e-mail]