- Those that are soluble in water form electrolytic solutions that are good
conductors of electricity. There is, however, a wide range in the solubilities
of ionic compounds. For example, at 25°C, 92 grams of sodium nitrate
(NaNO 3 ) dissolves in 100 grams of water, while only 0.0002 grams of
barium sulfate (BaSO 4 ) dissolves in the same mass of water.
PROPERTIES OF MOLECULAR CRYSTALS AND LIQUIDS
Experiments have shown that these substances have the following general
properties:
- Neither the liquids nor the solids conduct electric current appreciably.
- Many exist as gases at room temperature and atmospheric pressure, and
many solids and liquids are relatively volatile. - The melting points of solid crystals are relatively low.
- The boiling points of the liquids are relatively low.
- The solids are generally soft and have a waxy consistency.
- A large amount of energy is often required to decompose the substance
chemically into simpler substances.
CHAPTER SUMMARY
The following terms summarize all the concepts and ideas that were introduced in
this chapter. You should be able to explain their meaning and how you would use
them in chemistry. They appear in boldface type in this chapter to draw your
attention to them. The boldface type also makes it easier for you to look them up if
you need to. You could also use Internet search engines like google.com on your
computer to get a quick and expanded explanation of these terms, laws, and
formulas.
covalent bond
dipole-dipole attraction
electrostatic repulsion
hybridization
hydrogen bond
ionic bond
London dispersion forces
metallic bond
pi bond
resonance structure
stable octet