101 / 912
93
Copyright © 2017 Pearson Education, Inc.
CHAPTER 2
Acids and Bases: Central to Understanding Organic Chemistry
Important Terms
acid (Brønsted acid)
a species that loses a proton.
acid–base reaction
a reaction of an acid with a base.
acid dissociation constant
a measure of the degree to which an acid dissociates.
acidity
a measure of how easily a compound gives up a proton.
base (Brønsted base)
a species that gains a proton.
basicity
a measure of the tendency of a compound to share its electrons with a proton.
Brønsted acid
a species that loses a proton.
Brønsted base
a species that gains a proton.
buffer solution
solution of a weak acid and its conjugate base.
conjugate acid
the species formed when a base gains a proton.
conjugate base
the species formed when an acid loses a proton.
delocalized electrons
electrons that are shared by three or more atoms (that is, do not belong to a single
atom nor are they shared in a bond between two atoms).
equilibrium constant
the ratio of products to reactants at equilibrium.
Henderson–Hasselbalch
p
K
a
=
pH
+
log
3
HA
4 > 3
A
-
4
equation
inductive electron
the pull of electrons through sigma bonds by an atom or by a group of atoms.
withdrawal
Lewis acid
a species that accepts a share in an electron pair.
Lewis base
a species that donates a share in an electron pair.
pH
the pH scale used to describe the acidity of a solution
1
pH
=
-
log
3
H
+
42
.
p
K
a
a measure of the tendency of a compound to lose a proton (
p
K
a
=
-
log
K
a
,
where
K
a
is the acid dissociation constant).
proton
a positively charged hydrogen ion.
proton transfer reaction
a reaction in which a proton is transferred from an acid to a base.
resonance
delocalized electrons.
resonance contributors
structures with localized electrons that together approximate the true structure of a
compound with delocalized electrons.
resonance hybrid
the actual structure of a compound with delocalized electrons.