pH Calculations
Terms
Acid
-
A substance that has the potential to donate a proton or accept an electron
pair.
Acidic
-
Having a pH less than 7 or a pOH greater than 7.
Base
-
A substance that can accept a proton, release OH-, or donate an
electron pair.
Basic
-
Having a pH greater than 7 or a pOH less than 7.
Buffer
-
A solution composed of an acid and its conjugate base that serves to
moderate the pH of the
solution.
Conjugate Acid
-
A molecule that can be described as a base that has gained one proton.
Conjugate Base
-
A molecule that can be described as an acid that has lost one proton.
Dissociate
-
Separate into its ion constituents.
Hydrolysis
-
A reaction that modifies a water molecule. In acid-base chemistry this
usually
refers to the reaction of
a solute which changes the pH of an aqueous solution.
pH
-
A measure of the hydrogen ion concentration, it is equal to - log
[H+].
pK
a
-
A measure of the strength of an acid, it is equal to - log
K
a, where K
a is the acid dissociation
constant
in water.
pK
b
-
A measure of the strength of a base, it is equal to log
K
b, where K
b is the base dissociation
constant
in water.
pOH
-
A measure of the hydroxide ion concentration, it is equal to - log [OH-
].
Polyprotic Acid
-
An acid that can donate more than one proton.
Strong Acid
-
An acid with a pK
a less than zero. Strong acids
completely
dissociate in water.
Strong Base
-
A base with a pK
b less than zero. Strong bases completely
dissociate in water.
Weak Acid
-
An acid with a pK
a greater than zero. Weak acids do not
completely dissociate in water.
Weak Base
-
A basewith a pK
b greater than zero. Weak bases do not
completely dissociate in water.
