The pH Scale and Indicators
Notes
The pH Scale
pH
The _____
scale is a measure of the
hydronium
________________
ion concentration
in a solution. The pH value for a solution
negative
is the ________________
value of the
exponent
________________
that represents the
concentration
actual hydronium ion _______________.
Since hydronium ion concentrations are
small
numbers so ____________ that they
are expressed as negative powers of
negative
ten
____________,
a small ___________
higher
exponent means a ____________
hydronium ion concentration.
Concentrations can range from greater
100
10-14
than _______
down to ________.
Therefore the pH scale ranges from
14
0
7
______
to ______.
A pH of _____
is
a neutral solution.
Concentration of H30+
as a POWER
Concentration of H30+
as a DECIMAL
pH Value
0
1
2
3
…………………………………………
…………………………………………
…………………………………………
6
7
8
…………………………………………
…………………………………………
…………………………………………
14
If the pH is below 7, this means that there
hydronium
is a large concentration of ____________
acidic
ions, and therefore is ______________.
above
Bases have pH values __________
7.
stronger
The further away from 7, the ____________
the acid or base. Strong acids have pH
below
values _____________
2. Strong bases
above
have pH values _______________
12.
Indicators
Indicators
____________
are substances that produce
color
____________
changes in acids and bases.
They are used to identify whether a solution
acid
base
is an___________
or ___________.
Litmus
______________
is the most common
red
indicator. Litmus will be __________
in
blue
an acid and ___________
in a base.
Phenolphthalein
____________________
is also a common
indicator. Phenolphthalein is clear in acid,
pink
but turns a distinct ___________
color in
bases
____________.
Some indicators even change color at
ranges
Universal
different pH __________.
___________
indicator is a mixture of many indicators
color
and turns a different ____________
for
pH
almost every _____
value.