Guide to Purchasing Chemicals
Knowing which chemical to buy and where to purchase it can be a confusing part of preparing for your science fair project. This guide will help you navigate some of those challenges.
Grades of Chemicals
Most, but not all, chemicals are labeled with a grade. The grade indicates how pure the chemical is. The greater the quantity of other chemicals, metals, water, or other impurities in the chemical, the lower the grade. There are many different grading standards, but the three you are most likely to encounter are: reagent grade, laboratory grade, and technical grade. Of these, reagent grade is the most pure and technical grade is the least pure. See the table below for more details. Manufacturing pure chemicals can be time-consuming and expensive; for this reason, higher-grade chemicals cost more than lower-grade chemicals. For the purposes of most science fair projects, laboratory- or technical-grade chemicals are of sufficient purity. When in doubt, purchase laboratory-grade. If a Science Buddies project requires reagent-grade chemicals this will always be specifically stated in the Materials and Equipment section of the project. If you are ordering chemicals from an online distributor and do not know which grade to purchase, consult the customer-service representative or your chemistry teacher.
|Chemistry Grade||Alternative Name for Grade||Purity||Uses|
|Reagent||ACS||Highest purity available; meets or exceeds standards set by the American Chemical Society (ACS)|| |
|Laboratory||Lab||Relatively high purity, but may contain small amounts of impurities|| |
Local Resources for Purchasing Common Chemicals
Some chemicals have common household uses either in beauty and hygiene, laundry and cleaning, building maintenance, or gardening. These chemicals can be bought from local stores rather than ordered from specialty companies. The table below lists a variety of common chemicals and what you need to know to purchase them locally. Unlike chemicals bought from chemical supply companies, when bought locally these common chemicals are unlikely to come with Material Safety Data Sheets (MSDS). For general information about handling chemicals, see the Chemical Safety Guide. For specific information about how to handle and dispose of these chemicals, consult the "student-friendly" Chemical Database maintained by Oxford University.
|Chemical Name||Chemical Formula||Common Name||Where to Buy||Notes||Hazards|
|Acetic acid, ethanoic acid||CH3COOH + H2O||White vinegar||Grocery store||Contains approximately 5%-8% acetic acid in water|
|Acetone, propanone||CH3COCH3||Acetone and nail polish remover||Hardware or drug store||Acetone is commonly used as a paint thinner and can be bought at hardware stores. It is also the main ingredient in most nail polish removers, but check labels carefully because some nail polish removers include other chemicals.||Flammable|
|Ammonium hydroxide||NH4OH + H2O||Household ammonia||Grocery store||Contains approximately 10% ammonium hydroxide in water||Corrosive|
|Boric acid, boracic acid||H3BO3||Boric acid||Drug store|
|Calcium carbonate||CaCO3||Precipitated chalk (powder)||Drug store|
|Calcium chloride||CaCl2||Road salt||Hardware store||Read the label to make sure it is pure calcium chloride; sometimes other chemicals are added to help melt snow.|
|Calcium hydroxide||Ca(OH)2||Slaked lime, garden lime, or hydrated lime||Hardware store and garden center||Avoid breathing powder. Avoid eye contact.|
|Calcium oxide||CaO||Quicklime||Builder's supply store||Corrosive|
|Calcium sulfate||CaSO4 + H2O||Plaster of Paris, or gypsum||Hardware store|
|Glucose||C6H12O6 + H2O||Solution of corn syrup||Grocery store||Most chemistry uses will call for a diluted solution of corn syrup and water, the exact ratio depends on the application.|
|Hydrochloric acid||HCl + H2O||Muriatic acid||Hardware or pool supply store||Contains approximately 25% hydrochloric acid in water||Toxic and corrosive|
|Magnesium sulfate||MgSO4 + 7H2O||Epsom salt||Grocery or drug store|
|Manganese dioxide||MnO2||Pyrolusite||Hardware store|
|Naphthalene||C10H8||Moth balls||Hardware store|
|Oxalic acid||H2C2O4 + 2H2O||Non-chlorine bleach powder cleanser||Grocery or hardware store||A commonly available brand is Bar Keepers Friend®|
|Potassium nitrate||KNO3||Saltpeter||Garden center or hardware store||Oxidizing|
|Sodium bicarbonate||NaHCO3||Baking soda||Grocery store||Do not substitute with baking powder; baking powder contains additional chemicals.|
|Sodium chloride||NaCl||Table salt||Grocery store||Read the label carefully to make sure you are buying pure salt and not iodized salt.|
|Sodium hydroxide||NaOH||Caustic soda or lye||Grocery store||A commonly available brand is Drano®. Caution: keep out of eyes, can cause blindness.||Corrosive|
|Sodium tetraborate||Na2B4O7 + 10H2O||Borax||Drug or grocery store||A commonly available brand is 20 Mule Team® borax.|
|Sucrose||C12H22O11||Cane sugar||Grocery store|
|Zinc chloride||ZnCl2 + H2O||Tinner's fluid||Hardware store||Corrosive|
Corrosive chemicals can harm living tissue on contact. Diluted solutions of these chemicals may not be corrosive.
Oxidizing chemicals can cause other materials to combust more readily or make fires burn more fiercely. Always store oxidizers away from flammable or combustible materials, as well as sources of heat, flame, or sparks. Be sure to carefully examine the MSDS label, or a chemical database to determine which materials are incompatible.
Toxic chemicals can cause bodily harm if ingested, inhaled, or if they come in contact with your skin.
Purchasing Chemicals Online
If you need a chemical for your science fair project that cannot be bought locally (see table above), you will need to purchase it from a chemical supply company. For more information about online distributors of chemicals see: Science Buddies Approved Supplier Program.
Wikipedia Contributors. (2008, February 29). Common chemicals. Wikipedia: The Free Encyclopedia. Retrieved April 23, 2008 from http://en.wikipedia.org/w/index.php?title=Common_chemicals&oldid=194817053