A pycnometer is a device for measuring the density of liquids. It is a glass flask with a close fitting ground glass stopper having a
capillary hole through it. (a) The
volume of the pycnometer is determined by using distilled water
at 20°C with a known density of
0.99820 g/mL. First, the water is
filled to the rim. With the stopper
in place, the fine hole allows the excess liquid to escape. The pycnometer is then carefully dried with
filter paper. Given that the masses of the empty pycnometer and the same one filled with water are
32.0764 g and 43.1195 g, respectively, calculate the
volume of the pycnometer. (b) If the mass of the
pycnometer filled with ethanol at 20°C is 40.8051 g,
calculate the density of ethanol. (c) Pycnometers can
also be used to measure the density of solids. First,
small zinc granules weighing 22.8476 g are placed
in the pycnometer, which is then filled with water. If
the combined mass of the pycnometer plus the zinc granules and water is 62.7728g, what is the density of zinc?