94 DIY Science: Illustrated Guide to Home Chemistry Experiments
EvdRE y Ay SEpARATIoNS
Mixtures are the starting points for many of the
materials we use every day.- Refineries use distillation and other separation
methods to process crude oil—a complex mixture
of hydrocarbons—into gasoline, diesel fuel, and
hundreds of other useful organic compounds. - Industrial chemists synthesize thousands of
valuable compounds, from pharmaceuticals and
plastics to dyes, which must be extracted from
complex mixtures of by-products. These compounds
are often purified using one or more
of the separation methods that we’ll examine in
this chapter. - Mining companies extract, crush, and treat tons
of rock to obtain only a few grams of a precious
metal ore. For example, typical gold ore contains less
than 50 grams of gold per 1,000 kilograms of ore
(0.005%).
LABORATORY 6 .1:
dIffERENTIAL SoLUBILITy: SEpARATE SANd ANd SUCRoSE
Differential solubility was one of the earliest
methods developed for separating mixtures.
Differential solubility depends on the fact that
different substances have different solubility
in different solvents. In this lab, we’ll examine
the simplest example of differential solubility:
separating a mixture of two compounds, one
of which is freely soluble in water and one of
which is insoluble in water.
SBSTITUTIU oNS ANd modIfICATIoNS- You may substitute any convenient heat-resistant
containers of similar size for the beakers. - You may substitute an ordinary kitchen funnel for the
filter funnel, and a coffee filter for the filter paper. - If the sand is not completely dry, spread it in a thin
layer and dry it in a microwave or conventional oven. - You may substitute ordinary table sugar for the sucrose.
RIREEqU d EqUIpmENT ANd SUppLIES£ goggles, gloves, and protective clothing£ balance and weighing papers£ hotplate£ microwave or conventional oven£ beaker, 150 mL (2)£ watch glass£ filter funnel£ filter paper£ stirring rod£ wash bottle (water)£ dry sand (10.0 g)£ sucrose (10.0 g)£ water