14 DIY Science: Illustrated Guide to Home Chemistry Experiments
When Robert built his first home chemistry lab in the early
1960s, some laboratory glassware was still made from ordinary
flint glass. Nowadays, with the exception of glass tubing, some
volumetric (measuring) glassware, and similar items, nearly all
laboratory glassware is made from Pyrex or other heat-resistant
borosilicate glasses like Kimax, Endural, or Bomex. Still, it’s
worth checking. Flint-glass labware is ill-suited for any task
that involves heat, whether that heat is applied externally or
produced by a reaction.
Nowadays, a lot of “glassware” is actually made of plastic. Plastic
has some advantages over glass; notably, that it usually doesn’t
break if you drop it. Plastic labware is often (but not always)
less expensive than glass equivalents. Because plasticware
is produced by injection molding, it’s easy and inexpensive to
produce complex shapes that are expensive to produce in glass.
Against these advantages, plasticware has several disadvantages.
Obviously, plasticware is less heat-resistant than glassware.
Although good plasticware stands up to autoclaving, it cannot
be heated over a flame or used for reactions that produce high
temperatures. Plasticware may be damaged by organic solvents,
oxidants, and some other chemicals. Because plasticware
does not possess the vitreous surface of glassware, it is more
difficult to clean thoroughly and may be permanently stained or
otherwise contaminated by some chemicals, as Figure 3-1 shows.On balance, we prefer to use glassware for most purposes.
We suggest that you devote most of your glassware budget to
actual glassware, and buy plasticware only for tasks where its
advantages outweigh its disadvantages.Labware, whether glass or plastic, is commonly available in
at least two quality grades. Laboratory-grade glassware—also
called professional-grade—is more expensive, better finished,
often more precisely graduated, of heavier construction, better
annealed, and is usually made in the United States, Europe,
or Japan from Pyrex or other name-brand borosilicate glass.
Student-grade glassware—also called economy-grade or
educational-grade—is less expensive (sometimes much less),
cruder in appearance, often less precisely graduated, may use
thinner glass, often has annealing of questionable quality, and
is usually made in China from Bomex or other inexpensive
borosilicate glass. There are similar differences in grades
of plasticware.GENERAL pURpoSE GLASSwARE ANd pLASTICwARE
Any chemistry lab requires a good assortment of glassware to mix, store, measure, and
dispense solutions. All of it needn’t be actual labware. To some extent, you can substitute
ordinary household items such as drinking glasses, measuring cups, empty soft drink bottles,
and so on. But you’ll also need at least some formal labware for tasks that require it.
FIGURE 3-1:
A plastic graduated cylinder damaged by chemicals
DHEOPR T FLASK AnD
TURn AROUnD SLOWLY
Before you order any laboratory glassware, make sure that
it’s legal for you to possess it. We know that sounds strange,
but legislators in some jurisdictions—in an attempt to
eliminate underground meth labs—have passed laws that
make it illegal to possess some pretty innocuous items.
For example, in Texas it’s illegal to possess an Erlenmeyer
flask, unless you have a permit for it.
We are not making this up.z