Setting Up a Home Science Laboratory Part III – Chemicals on the Cheap

MAKE_sci_GEN_190px.gif

This article is based on material originally published in Illustrated Guide to Home Chemistry Experiments: All Lab, No Lecture, by Robert Bruce Thompson, and the not-yet-published Illustrated Guide to Forensics Investigations: Uncover Evidence in Your Home, Lab, or Basement, by Robert Bruce Thompson and Barbara Fritchman Thompson.

 

Laboratory chemicals are expensive, at least if you buy them from specialty lab supply vendors. Fortunately, there are many alternative sources for good quality, useful chemicals at reasonable prices. In fact, it’s possible to stock a home lab pretty comprehensively while buying only a few chemicals from specialty sources.

These alternative sources are many and varied, including the drugstore, supermarket, hardware store, or home improvement center, auto parts store, lawn and garden store, and pottery supply store. The following image shows just the first dozen or so chemicals that came to hand when I did a quick pillage of my lab to set up this shot. There are literally dozens more like them in my lab.

local chemicals

The purity of these chemicals ranges from very high (USP or FCC grades, intended for human consumption) to the lower practical and technical grades. For routine use, even practical or technical grade chemicals often suffice, and many of the impure chemicals can be purified to very high standards using ordinary lab procedures such as recrystallization and distillation, which we’ll cover in later articles.

Furthermore, you’re not limited to the chemicals offered for sale. You can use these readily-available chemicals to synthesize other chemicals. For example, in one of our videos, Dr. Mary Chervenak reacts copper(II) sulfate (root killer) with sodium bicarbonate (baking soda) to form pure copper(II) carbonate. In a later lab session, we react a portion of that copper(II) carbonate with acetic acid (distilled white vinegar) to produce copper(II) acetate, another portion with hydrochloric acid (muriatic acid from the hardware store) to produce copper(II) chloride, and a third portion with nitric acid to produce copper(II) nitrate. In yet another lab session, we react muriatic acid with steel wool to produce iron(II) chloride (ferrous chloride) and iron(III) chloride (ferric chloride). In still another, we convert a pound of barium carbonate purchased for about three bucks from a pottery supplies vendor into about $50 worth of barium chloride, barium nitrate, and barium hydroxide. And so on.

Pottery supply stores in particular are an excellent inexpensive source for many hard-to-find chemicals, used mostly in glazes. Most chemicals are sold in one-pound and larger packages (often sealed paper or plastic bags), although most vendors also offer half-pound, quarter-pound, or smaller quantities. Although the chemicals are technical grade, they’re often of surprisingly high purity. (Potters will not tolerate impure chemicals ruining a finished piece, which pottery supply stores are well aware of.) Carbonates are the most useful form of these chemicals, because the only byproducts of their reactions with acids are water and carbon dioxide. For example, reacting barium carbonate with hydrochloric (muriatic) acid yields only barium chloride (the desired product), water, and carbon dioxide, making it easy to purify the product.

The image below shows some of the “building block” chemicals I bought from Seattle Pottery Supply. From these, I can synthesize literally dozens of other useful chemicals. I paid about $60 for these chemicals, which with a few hours work, I can convert to several hundred dollars’ worth of other useful chemicals.

pottery chemicals

For many home chemists, it’s a point of pride to synthesize and purify their own chemicals. It is immensely satisfying to look to a bottle on the shelf and know that you made what’s in that bottle, that it’s just as pure as the expensive commercial ACS Reagent grade chemical sold by specialty vendors, and that making it cost a tenth of what it would have cost to buy it.

Darkrooms and Pyrotechnics

Before digital cameras pretty much killed hobbyist film photography, camera stores were one of the best alternative sources for laboratory chemicals. Most towns had at least one camera store that stocked dozens of pure chemicals that are now available only from specialty chemical suppliers. Silver nitrate, potassium bromide, potassium iodide, nitric acid, iodine, various organics–the list went on and on. Such camera stores are pretty much history now, and those that remain no longer stock much in the way of darkroom chemicals other than prepackaged developers and so on.

There are still several on-line darkroom supply vendors that sell individual chemicals. These chemicals are invariably “photo grade,” which may range from reagent-grade purity to practical grade, depending on the specific chemical. Package quantities vary widely, from a gram or less for some very expensive chemicals (usually silver- or platinum-based), through five pounds or more for inexpensive chemicals that are used in large amounts (such as sodium thiosulfate for fixer). Prices are all over the map. For some chemicals, prices are as low or lower (sometimes, much lower) than those of specialty vendors; for others, the prices are outrageously high. Buyer beware. Here are some darkroom supply vendors you may want to check out (note: we have not purchased from any of them):

Pyrotechnic suppliers are another good source for chemicals, but there’s a catch. Many hobbyists steer clear of pyrotechnic suppliers because they don’t want to draw government attention to themselves. Various government agencies, including the Department of Homeland Security (DHS) and the Consumer Product Safety Commission, take a strong interest in anyone who buys chemicals that can be used to make explosives or fireworks. We’ve never bought chemicals from any of these vendors for that reason, but if you’re comfortable doing so, here are a couple of pyrotechnic vendors:

Key Chemicals

Here are some chemicals you’ll need to stock up your lab, both for general use and for use in synthesizing other chemicals. Those in bold are high-priority chemicals that you’ll probably want to stock in reasonable quantities, say a pound (~ 500 g) for solid chemicals, and a pint to a gallon (500 mL to 4 L) for liquid chemicals, particularly if you plan to do any syntheses. Recommended quantities are shown in parentheses.

  • Acetic acid – You may need glacial (~ 99%) acetic acid for some purposes, but often a dilute solution suffices. Distilled white vinegar is very pure (FCC grade) acetic acid in 5% concentration (about 0.83 M). If necessary, you can concentrate it further by distillation. The low molarity makes vinegar less than ideal for synthesizing chemicals in bulk because so much is required and so much water must be removed to isolate the product, but it is suitable for making up dilute solutions (~ 0.1 M) of various acetate salts. (one pint or more)
  • Acetone – Technical grade acetone, available by the pint, quart, or gallon in the paint section of any hardware store or home improvement center, is more than pure enough for routine lab use. It’s useful as a general solvent, a chromatography solvent, as a final rinse when you synthesize a water-soluble chemical, and as a final rinse when you wash up your glassware (one pint or more).
  • Aluminum – Ordinary kitchen aluminum foil is fine for most purposes, as are aluminum beverage cans. (Both of these are coated with plastic on at least one side, which usually presents no problem.) You can also use any form of aluminum hardware or scrap. We picked up several aluminum window screen frames that had been put to the curb in our neighborhood for bulky-item pickup day. The frames are pure aluminum and we even recycled part of the plastic screen for use as sifters in our lab.
  • Aluminum oxide (~ $3/pound as alumina from a pottery supplies store) is useful primarily for making your own thin-layer chromatography plates, at a cost of a few cents each versus a couple dollars each for commercial TLC plates. (If you want to make TLC plates, order a few ounces of alumina in the finest powder available.)
  • Ammonia – The clear, non-sudsy household ammonia sold in supermarkets is actually reasonably pure 10% aqueous ammonia (~ 5.8 M), which is concentrated enough for most purposes, including syntheses. (Because ammonia is so extremely soluble even in boiling water, household ammonia cannot be concentrated by distillation. If you need a higher concentration, you’ll need to buy it.) Buy the cheapest generic household ammonia and make sure it doesn’t contain soap. Ammonia is used as-is in many experiments, and can be reacted with mineral acids or organic acids to form numerous salts, such as ammonium acetate, ammonium chloride, ammonium oxalate, ammonium phosphate, ammonium sulfate, and so on (one quart).

For example, here’s how to make up dilute bench solutions of two ammonium compounds.

  • Ammonium acetate solution, 0.1 M – To make up 100 mL of this solution, add household ammonia dropwise (about 1.7 mL) to 12.0 mL of distilled white vinegar until the solution just turns red litmus paper blue and then dilute to 100 mL.
  • Ammonium chloride solution, 0.1 M – To make up 100 mL of this solution, add 31.45% muriatic acid dropwise (about 1.0 mL) to 1.7 mL of household ammonia until the solution just turns blue litmus paper red and then dilute to 100 mL.
  • Ammonium nitrate – Although you can make ammonium nitrate by reacting ammonia with nitric acid, it’s much cheaper to buy ammonium nitrate at a lawn and garden store, where it’s sold in pure form in 1-pound to 50-pound bags as 33-0-0 or 34-0-0 fertilizer. Store separately from all other chemicals (four ounces or more).
  • Barium carbonate – (~ $3/pound from a pottery supplies store) can be reacted with mineral acids, organic acids, or sodium hydroxide to produce barium chloride, barium nitrate, barium hydroxide, and other barium salts, for which you might otherwise have to pay several dollars for a 5 g to 25 g bottle (four ounces or more, if you want to synthesize barium salts).
  • Calcium carbonate – (~ $2/pound as whiting, from a pottery supplies store) can be reacted with mineral acids or organic acids to produce calcium acetate, calcium chloride, calcium nitrate, and other calcium salts. Ordinary blackboard chalk is also primarily calcium carbonate, as are some antacids (four ounces or more, if you want to synthesize calcium salts).
  • Calcium chloride – is used in some experiments. It is the primary or sole chemical present in some “ice melt” products, and is also available from brewing/winemaking suppliers and from some garden supply stores as a trace nutrient fertilizers. You can also make up calcium chloride yourself by reacting calcium carbonate with hydrochloric (muriatic) acid. (one ounce, if you need it)
  • Calcium hydroxide – is available from garden supply stores, usually as “hydrated lime”, “slaked lime”, or simply “lime” (which may also contain calcium oxide and/or calcium carbonate). The primary use of calcium hydroxide in a home lab is as lime water, a saturated solution of calcium hydroxide that forms a precipitate of calcium carbonate if carbon dioxide gas is passed through it. (one ounce, if you need it)
  • Carbon – you can buy carbon in the form of activated charcoal in some drugstores and the aquarium section of some pet stores. (one ounce or more)
  • Cobalt carbonate (~ $50/pound or $4/ounce from a pottery supplies store) can be reacted with hydrochloric acid to produce cobalt(II) chloride, or with nitric acid to produce cobalt(II) nitrate. We bought 1 ounce of cobalt carbonate and converted half an ounce each to cobalt chloride and cobalt nitrate. Because cobalt itself is quite expensive, the cost savings in making your own cobalt salts are less compelling than with most other syntheses. (one ounce or more, if you want to synthesize cobalt salts)
  • Copper carbonate (~ $7/pound from a pottery supplies store) can be reacted with various acids to produce copper(II) acetate, copper(II) chloride, copper(II) nitrate, or even copper(II) sulfate. However, in this instance the pottery chemical price is actually more than it costs to buy copper(II) sulfate at the hardware store and react it with baking soda to make your own copper(II) carbonate. Buy copper(II) carbonate only if the convenience outweighs the higher price.
  • Copper(II) sulfate – you can buy this chemical in very pure form in the plumbing section of hardware stores and home improvement centers as root killer. (Make sure the bottle lists copper(II) sulfate as the only ingredient). We bought a 2-pound bottle of Enforcer Drain Care Root Kill for about $8 at Lowes. It lists an assay on the label as 99% pure copper(II) sulfate, which is near reagent grade. Also available in pure form from pottery supply stores for ~$3.50/pound. Copper(II) sulfate is used as is in many experiments, and is also a useful precursor for making your own copper(II) carbonate, copper(II) chloride, copper(II) nitrate, and other copper salts. (four ounces or more)
  • Citric acid – you can buy citric acid inexpensively and in very pure form (FCC) as “sour salt” in supermarkets. Citric acid is used in several common experiments and is also useful for making up buffer solutions and for synthesizing citrate salts. (one ounce or more)
  • Distilled water – Water is a chemical just like any other. You’ll need distilled water for general lab use, including making up solutions, rinsing glassware, and so on. You can buy it cheaply by the gallon at the supermarket. Make sure the label says “distilled” rather than “spring water” or something similar. (gallon or more)
  • Ethanol – Ethanol is available in drugstores by the pint or quart in concentrations from 70% to 95%, under that name or as ethyl alcohol or rubbing alcohol. Note that most drugstore “rubbing alcohol” is actually isopropanol rather than ethanol. Drugstore ethanol is USP grade, which is extremely pure. Ethanol is useful as a general solvent, chromatography solvent, reactant, and as fuel for an alcohol burner. (Buy at least a pint of the 95% concentration, if available)
  • Glycerol – sold under that name or as glycerin or glycerine (not glycin, which is an entirely different chemical) in drugstores, glycerin is used in some experiments and syntheses, but its primary uses in a home lab are for lubricating rubber stoppers and as a temporary mounting medium for microscope slides. (smallest available bottle)
  • Hydrochloric acid – sold in hardware stores and home improvement centers as muriatic acid, and is generally quite pure. Concentrated hydrochloric acid from a lab supplier is about 37% (~ 12 M). Muriatic acid is available in several concentrations, from 14.5% (4.7 M, for lowering swimming pool pH) up to 29% (9.4 M) or 31.25% (10 M), for cleaning or etching concrete. The 29% or 31.45% concentrations typically cost a couple bucks a quart or five bucks a gallon. Either can be substituted for 37% hydrochloric acid for most purposes. (one quart to one gallon)
  • Hydrogen peroxide – the 3% hydrogen peroxide sold in drugstores is useful for many experiments. You can also buy more concentrated hydrogen peroxide at a beautician’s supply store. A pint of 12% H2O2 (called “40 volume”) costs about $3. The 12%/40-volume stuff is concentrated enough to work in many experiments that specify 30% hydrogen peroxide; simply use about 2.5 times as much 12% as is specified for the 30% concentration. Higher concentrations, as much as 30% to 35%, are sometimes available in pool supplies stores, often under the name Liquid Oxygen. (one pint of 3% or higher concentration)
  • Iodine – formerly widely available in crystal form for water purification, iodine is now a DEA List I chemical, which means it’s harder to find. Iodine is used in many experiments, as a reactant, indicator, test reagent, or microscope slide staining solution. For most purposes you can substitute iodine tincture (a dilute solution of iodine and potassium iodide in ethanol) or Lugol’s solution (the same, but uses water as a solvent instead of ethanol). Although less used than formerly, iodine tincture and Lugol’s solution are still widely available in one-ounce bottles (the DEA limit) in drugstores. We picked up a one-ounce bottle of 2% iodine tincture at Walgreens for $3. Be careful. Many vendors sell iodine tincture and/or Lugol’s solution at outrageous prices. We’ve seen prices of $20 and even $30 for a small bottle. (for use as an indicator, test reagent, or slide stain, one one-ounce bottle; if you need iodine in larger amounts, you can easily synthesize it yourself from potassium iodide.)
  • Iron – used in many common experiments and syntheses, usually in the form of iron filings. You can substitute soapless steel wool, which is available inexpensively in the form of steel wool pads in the paint section of hardware stores and home improvement centers. You can synthesize various iron(II) (ferrous) and iron(III) (ferric) salts by reacting steel wool pads with various acids such as hydrochloric, nitric, or sulfuric. These syntheses can be tuned to favor the ferrous or ferric salts by keeping either the steel wool or the acid in excess. You can also produce various double salts, such as ferric ammonium sulfate, by using a calculated excess of the acid and neutralizing the solution with ammonia. (one or two pads)
  • Isopropanol – sold in drugstores under that name or as isopropyl alcohol or rubbing alcohol (some rubbing alcohol is ethanol rather than isopropanol). Common concentrations run from 70% to 99%, with 70%, 91%, 95%, and 99% most common. Isopropanol is used in many experiments as a general solvent, chromatography solvent, or reactant, and is also useful as fuel for an alcohol burner. (one pint of 91% or 99% isopropanol)
  • Lead carbonate (~ $3/pound from a pottery supplies store) is infrequently used in pottery nowadays because of lead toxicity, so not all pottery supply stores carry it. Lead carbonate can be reacted with acetic acid to produce lead(II) acetate or nitric acid to produce lead(II) nitrate. (four ounces or more, if you want to synthesize lead salts)
  • Lithium carbonate (~ $7/pound from a pottery supplies store) can be used to synthesize lithium acetate, lithium chloride, lithium hydroxide, and other lithium salts. (four ounces or more, if you want to synthesize lithium salts)
  • Magnesium sulfate – is used in several common experiments. The heptahydrate form is sold in drugstores as Epsom salts for about a buck a pound, and is of very high purity. (a few ounces to a pound)
  • Magnesium carbonate (~ $3/pound from a pottery supplies store) can be reacted with mineral acids or organic acids to produce magnesium acetate, magnesium chloride, magnesium nitrate, and other magnesium salts. (four ounces or more, if you want to synthesize magnesium salts)
  • Manganese carbonate (~ $4/pound from a pottery supplies store) can be reacted with hydrochloric acid to produce manganese chloride, with nitric acid to produce manganese nitrate, or with sulfuric acid to produce manganese sulfate. (four ounces, if you want to synthesize manganese salts)
  • Methanol – is useful as a general laboratory solvent, as a chromatography solvent, and as a precursor in several common syntheses. Methanol is sometimes used as fuel in alcohol lamps, although its invisible flame presents an obvious hazard. Methanol is available in the paint section of some hardware stores and home improvement centers, under that name or as wood alcohol, but many do not carry it. Auto parts stores sell 99% methanol in 12-ounce bottles for a buck or so as a fuel additive under the brand name HEET. (Make sure to get original HEET, rather than ISO-HEET, which is isopropanol.) Methanol-based fuel additives contain about 1% rust inhibitors and other additives, which usually present no problem for routine use. If you want purer methanol, you can distill HEET (carefully; it’s extremely flammable). (one 12-ounce bottle)
  • Nickel carbonate (~ $30/pound or $3/ounce from a pottery supplies store) can be reacted with acetic acid to produce nickel acetate, with hydrochloric acid to produce nickel chloride, or with nitric acid to produce nickel nitrate. (one ounce or more, if you want to synthesize nickel salts)

The Special Case of Nitric Acid

Concentrated nitric acid is difficult to find locally, and is expensive to ship because shipping it in any quantity requires a hazardous material shipping surcharge. If you can find it locally, buy it. Otherwise, one good source of concentrated nitric acid is Elemental Scientific (www.elementalscientific.net), which offers ACS Reagent grade concentrated (68%) nitric acid in one-ounce, eight-ounce, and sixteen-ounce bottles at a good price. There is a $20 hazardous materials shipping surcharge, but Elemental can ship up to eight one-pint bottles for that one surcharge. If you can get together with other like-minded DIY science enthusiasts or home school families, you can combine your orders and obtain a pint or more of concentrated nitric acid for a reasonable price. In particular if you plan to synthesize your own chemicals and/or do qualitative/quantitative analysis experiments, you’ll want at least a pint of concentrated nitric acid on hand. Store separately from all other chemicals.

  • Oxalic acid – is commonly found in relatively pure (95% to 100%) form in hardware stores as wood bleach. (Not all wood bleaches are oxalic acid based; some use hydrogen peroxide or chlorine bleach. Check the label.) Oxalic acid is used as-is in some experiments, but is primarily useful for synthesizing oxalate salts such as ammonium oxalate. (an ounce or more, if you need it)
  • Petroleum ether – also known as ligroin, benzine (not benzene), and under several other names, petroleum ether is an ill-defined mixture of various alkanes, primarily pentanes and hexanes. In introductory chemistry lab sessions, it is useful primarily as a non-polar chromatography solvent. For most purposes, you can substitute toluene or xylene from the paint section of the hardware store. (small can, if you will be doing chromatography experiments)
  • Phosphoric acid – is sold in hardware stores as a rust remover (Naval Jelly) or for etching/cleaning concrete. It is also available in various concentrations and degrees of purity from some brewing/winemaking suppliers and hydroponics suppliers. Its primary use in a home lab is for synthesis of phosphate salts by reacting it with carbonates. (a few ounces, if you need it)
  • Potassium chloride – is sometimes sold in very pure (FCC) form as sodium-free salt in supermarkets (check the label). It is also available at some garden-supply stores in 1-pound and larger bags as potassium fertilizer. The pure form is sometimes useful as a source of potassium ions in various experiments. Fertilizer-grade potassium chloride can be purified by recrystallization or can be used as-is in synthesizing potassium chlorate from chlorine laundry bleach. (one ounce or more, if you need it)
  • Potassium dichromate – in relatively pure form is sold by pottery supply stores, either under that name or as potassium bichromate. Potassium dichromate is used in many experiments and some syntheses. (one ounce or more, if you need it)
  • Potassium nitrate – is available in relatively pure form from garden stores as fertilizer (under that name or as saltpeter) and from some pottery supply vendors. It is used as-is in some experiments, and is also a component of some test reagents. (a few ounces, if you need it)
  • Potassium permanganate – is used as-is in some experiments, and is a component of some test reagents. You can buy it from some aquarium suppliers, either in crystal form or as an aqueous solution. It’s also sold by Sears, Tractor Supply, and other vendors for use in treating water to remove iron. (one ounce)
  • Silver nitrate – is used in many experiments as a test reagent, usually as a 1% to 10% aqueous solution. It’s available in relatively pure form from some pottery suppliers. (a few grams)
  • Sodium bicarbonate – sold inexpensively and in extremely pure form in supermarkets as baking soda, sodium bicarbonate is used in many experiments as is and is also useful as a precursor chemical in synthesizing other chemicals and to precipitate toxic heavy metal ions and neutralize acid wastes before disposal. Finally, sodium bicarbonate can be used to neutralize acid spills and to extinguish fires. We bought a 12-pound resealable bag at Costco for $5. (large box or bag)
  • Sodium borate – better known by its common name borax, is readily available in supermarkets. It’s used directly in some experiments, but its primary use in a home lab is the qualitative borax-bead test for various metal ions. (an ounce, if you need it)
  • Sodium bromide – available at some swimming pool supply vendors, either by name or as “bromine base”. Can usually be substituted if an experiment calls for potassium bromide. (one ounce)
  • Sodium carbonate – For noncritical use, you can buy reasonably pure sodium carbonate in supermarkets as washing soda or from pottery supply stores as soda ash, but it’s easy to make very pure anhydrous sodium carbonate simply by spreading a pound or so of USP sodium bicarbonate (baking soda) in a thin layer on a baking pan and heating it in the oven for an hour or so to drive off water and carbon dioxide. Heating 500 g of sodium bicarbonate yields about 315 g of anhydrous sodium carbonate. (if you buy it, one pound or more)
  • Sodium chloride – ordinary iodized table salt is almost pure sodium chloride, with potassium iodide added (the “iodized” part of the name) as well as anti-caking agents. Popcorn salt and kosher salt lack the potassium iodide. For most purposes, either of those can be used as is. (one container of popcorn salt)
  • Sodium hydroxide – is the most commonly-used base in a home science lab. You can buy sodium hydroxide in pure form in some hardware stores as “crystal drain opener” (make sure the label says 100% sodium hydroxide). (several ounces to a pound or more)
  • Sodium hypochlorite – is used in many experiments and is useful as a general-purpose strong oxidizer. Ordinary chlorine laundry bleach is a 5.25% to 6.5% solution of sodium hypochlorite, mixed with sodium hydroxide and other contaminants, and is generally usable in any experiment that calls for sodium hypochlorite. Oddly, the cheapest generic chlorine laundry bleach is usually the purest. Name brand products include whiteners, scents, and other contaminants. (a few ounces)
  • Strontium carbonate (~ $4/pound from a pottery supplies store) can be reacted with mineral acids or organic acids to produce strontium acetate, strontium chloride, strontium nitrate, and other strontium salts. (four ounces or more, if you want to synthesize strontium salts)
  • Sulfur – you can buy sulfur of variable purity at garden supply stores, where it’s sold as a fertilizer, fungicide, and soil additive. The label may list an assay. We have seen bags of sulfur from garden supply stores with assays as high as 99%.
  • Sulfuric acid – battery acid sold by auto parts stores is typically 35% (~ 30% to 40%; ~ 5 M to ~7.5 M) sulfuric acid of reasonably high purity (contaminants can easily “poison” a lead-acid battery). Some drain cleaners are technical grade concentrated sulfuric acid, although they often contain significant amounts of various contaminants. Sulfuric acid in reasonably pure form is available from some art and craft suppliers, as well as metal/jewelry-making suppliers. (several ounces to one pint or more)
  • Toluene – formerly widely available in the paint section of hardware stores and home improvement centers, but is now harder to find. We found it at a Sherwin-Williams paint store. Toluene (methylbenzene) is useful as a general solvent and for chromatography. Xylenes (mixed dimethylbenzene isomers), which are still widely available in hardware and paint stores, can often be substituted as a solvent. (one pint)
  • Zinc – you can obtain very pure zinc by carefully opening an unused zinc-carbon battery (cell), removing the casing, and washing it thoroughly. The casing is 99%+ zinc. US cent coins minted in 1983 or later are almost pure zinc with extremely thin copper plating, which can be removed chemically or by sanding or tumbling. Zinc is a reactive metal, and combines readily with mineral acids to form zinc chloride, zinc nitrate, or zinc sulfate, or with sodium hydroxide to form sodium zincate. (a few ounces)

Get ’em while you can

If you plan to synthesize chemicals, you’ll need storage containers for them. One excellent solution is to use plastic 35mm film cans, which for now are usually free for the asking at most drugstores. These cans are made of chemical-resistant plastic, have tight-fitting lids, and are large enough to hold 25 mL of liquid or 50 to 100 grams of most solid chemicals. Get them while you can. The woman at the photo counter at our local Walgreen’s told me that they used to get 100 to 200 film cans a day. That’s now down to maybe five per day, as digital cameras kill 35mm film. I have a garbage bag full of them, which I use for my own purposes and to make up science sets for local kids.

film cans

Specialty Chemicals

For some laboratory chemicals, the most practical source is a specialty supplier. For example, such commonly used laboratory chemicals as phenolphthalein, potassium bromide, potassium ferricyanide, potassium ferrocyanide, potassium iodide, potassium thiocyanate, sodium thiosulfate, and many others may be difficult to obtain locally or to synthesize. You can buy these specialty chemicals individually from specialty laboratory supplies vendors, including Maker Shed.

August 28, 2009