Laboratory apparatus and reagents
A good grade of laboratory apparatus is adequate for all practical uses. Pyrex or a similar glassware of low solubility of low solubility and low coefficient of expansion is highly recommended. Reagents should be of analytical-reagent grade or known to meet the specification of purify established by the American chemical society. Lower grade of chemicals, even technical grade, may be used for some purposes, but the analyst must make sure that such grades do not contain undesirable amounts of certain impurities. It is not practical to buy a reagent grade of sodium hydroxide for purposes that require a high-purify sodium hydroxide. The best grades obtainable are too impure. It is just as easy to purify a cheaper grade in the laboratory, and it serve the purpose just as well, at a much lower cost. As an alternative, purified sodium hydroxide solutions may be purchased.