5 Steps to a 5 AP Chemistry 2019

Reactions and Periodicity ‹ 79

Acids and bases may be strong, dissociating completely, or weak, partially dissociat-

ing and forming an equilibrium system.(See Chapter 15 for the details on weak acids and

bases.) Strong acids include:

1. Hydrochloric, HCl


2. Hydrobromic, HBr


3. Hydroiodic, HI


4. Nitric, HNO 3


5. Chloric, HClO 3


6. Perchloric, HClO 4


7. Sulfuric, H 2 SO 4
   The strong acids above are all compounds that ionize completely in aqueous solution,
   yielding hydrogen ions and the anions from the acid.
   Strong bases include:


8. Alkali metal (Group IA) hydroxides (LiOH, NaOH, KOH, RbOH, CsOH)


9. Ca(OH) 2 , Sr(OH) 2 , and Ba(OH) 2
   The strong bases listed above are all compounds that dissociate completely, yielding the
   hydroxide ion (which is really the base, not the compound).
   Unless told otherwise, assume that acids and bases not on the lists above are weak and
   will establish an equilibrium system when placed into water.
   Some salts have acid–base properties. For example, ammonium chloride, NH 4 Cl, when
   dissolved in water will dissociate and the ammonium ion will act as a weak acid, donating
   a proton. We will examine these acid–base properties in more detail in the next section.
   Certain oxides can have acidic or basic properties. These properties often become
   evident when the oxides are dissolved in water. In most case, reactions of this type are not
   redox reactions.
   Many oxides of metals that have a +1 or +2 charge are called basic oxides (basic
   anhydrides), because they will react with acids.

+→ +

+→+++

FeO(s)6HCl(aq)2FeCl(aq) 3HO(l)

FeO(s)6H(aq)2Fe (aq) 3HO(l)

23 32

23

3

2

Many times they react with water to form a basic solution:

+→

+→+−+

NaO(s)HO(l) 2NaOH(aq)

NaO(s)HO(l) 2Na(aq)2OH(aq)

22

22

Many nonmetal oxides are called acidic oxides (acidic anhydrides), because they react

with water to form an acidic solution:

CO 22 (g)H+→O(l) HC 23 O(aq)

H 2 CO 3 (aq) is named carbonic acid and is the reason that most carbonated beverages

are slightly acidic. It is also the reason that soft drinks have fizz, because carbonic acid will

decompose to form carbon dioxide and water.

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