A supplementary document on the properties and theories of acids and bases.

1. xxxxxxxxxxxxxxxxxxxxxxx February 17, 2017
XI- Aristotle Friday- 9:00-10:00am
Reference:
Acids & Bases. (n.d.). Retrieved February 16, 2017, from
http://moodle.sd74.bc.ca/mod/book/tool/print/index.php?id=735
Three Acid-Base Theories
A. The Arrhenius Theory
• The Arrhenius theory defines an acid as a compound that can separated into atoms or ions in
water to yield hydrogen ions, H+ ; such that: HA H+
+ A-
• Thus, accordingly, a base is a compound that can dissociate in water to yield hydroxide ions,
OH - ; such that: MOH M+
+ OH-
• Simply, when an acid or base dissolves in water, a certain percentage of the acid or base
particles will break up, or separate into oppositely charged ions.
Table 1: Basic Properties of Acids and Bases

2. • Furthermore, acids and bases will neutralize each other when mixed. They produce water and
an ionic salt, neither of which are acidic or basic; such that: HA + MOH H2
0 + MA
B. The Brönsted-Lowry Theory
• The theory provides a more general definition of acids and bases that can be used to deal both
with solutions that contain no water and solutions that contain water.
• An acid is a substance from which a proton (H+ ion) can be removed.
• A base is a substance to which a proton (H+) can be added.
• Essentially, it defines an acid as a proton donor and a base as a proton acceptor.
◦ “When an acid loses a proton, the remaining species can be a proton acceptor and is called
the conjugate base of the acid. Similarly when a base accepts a proton, the resulting species
can be a proton donor and is called the conjugate acid of that base.”
• On the other hand, water, H2O, can be considered an acid or a base since it can lose a proton to
form a hydroxide ion, OH - , or accept a proton to form a hydronium ion, H3O+.
C. The Lewis Theory
• Accordingly, the Lewis definition is the most general theory, having no requirements for
solubility or protons.
• In this theory, an acid as a compound that can accept a pair of electrons and a base as a
compound that can donate a pair of electrons.
◦ “Lewis acids and bases react to create an adduct, a compound in which the acid and base
have bonded by sharing the electron pair.”
References:
Acid-Base Theories. (2012). Retrieved February 16, 2017, from
http://www.infoplease.com/encyclopedia/science/acids-bases-acid-base-theories.html
Brown, Theodore L. ... et al, Brown, T. L., LeMay, J. H., Bursten, B. E., Murphy, C. J., &
Woodward, P. -. (2009). Chemistry: the central science. - 11th Edition. Upper Saddle River, NJ:
Pearson Prentice Hall.