1. _Binary acids._ Acids containing only one element in addition to hydrogen are called _binary acids_. They are given names consisting of the prefix _hydro-_, the name of the second element present, and the termination _-ic_. Examples: hydrochloric acid (HCl); hydrosulphuric acid (H_{2}S). 2. _Ternary acids._ In addition to the two elements present in binary acids, the great majority of acids also contain oxygen. They therefore consist of three elements and are called _ternary acids_. It usually happens that the same three elements can unite in different proportions to make several different acids. The most familiar one of these is given a name ending in the suffix _-ic_, while the one with less oxygen is given a similar name, but ending in the suffix _-ous_. Examples: nitric acid (HNO_{3}); nitrous acid (HNO_{2}). In cases where more than two acids are known, use is made of prefixes in addition to the two suffixes _-ic_ and _-ous_. Thus the prefix _per-_ signifies an acid still richer in oxygen; the prefix _hypo-_ signifies one with less oxygen. ~Naming of salts.~ A salt derived from a binary acid is given a name consisting of the names of the two elements composing it, with the termination _-ide_. Example: sodium chloride (NaCl). All other binary compounds are named in the same way. A salt of a ternary acid is named in accordance with the acid from which it is derived. A ternary acid with the termination _-ic_ gives a salt with the name ending in _-ate_, while an acid with termination _-ous_ gives a salt with the name ending in _-ite_. The following table will make the application of these principles clear: ACIDS SYMBOL SALTS SYMBOL Hydrochloric HCl Sodium chloride NaCl Hypochlorous HClO Sodium hypochlorite NaClO Chlorous HClO_{2} Sodium chlorite NaClO_{2} Chloric HClO_{3} Sodium chlorate NaClO_{3} Perchloric HClO_{4} Sodium perchlorate NaClO_{4} EXERCISES 1. 25 cc. of a solution containing 40 g. of sodium hydroxide per liter was found to neutralize 25 cc. of a solution of hydrochloric acid. What was the strength of the acid solution? 2. After neutralizing a solution of sodium hydroxide with nitric acid, there remained after evaporation 100 g. of sodium nitrate. How much of each substance had been used? 3. A solution contains 18 g. of hydrochloric acid per 100 cc. It required 25 cc. of this solution to neutralize 30 cc. of a solution of sodium hydroxide. What was the strength of the sodium hydroxide solution in parts per hundred? 4. When perfectly dry sulphuric acid is treated with perfectly dry sodium hydroxide, no chemical change takes place. Explain. 5. When cold, concentrated sulphuric acid is added to zinc, no change takes place. Recall the action of dilute sulphuric acid on the same metal. How do you account for the difference?