ACIDS BASES
AND SALTS
ACID + BASE --> SALT + HOH
H-anion + cation-OH --> cation-anion + HOH
Neutralization
Acids release
H+ ions in
solution with water
Bases release OH- ions
in solution with water
The word “acidity”
refers to the concentration of
Hydrogen ions
H+ in solution. If there are more H+
Ions, then
the solution is more acidic!
The word “basic”
refers to the concentration of
Hydroxide ions
or OH- in solution. If there are
more
OH- ions,
the solution is more basic!
Acids
absorb hydroxides to neutralize a base
Bases
absorb hydrogens to neutralize an acid.
pH SCALE
A pH scale
is a way of measuring the
Concentration
of hydrogen ions in solution.
The scale
goes from 1 to 14
1 2
3 4 5
6 7 8 9
10 11 12 13
14
very neutral very
acidic basic
Acids have a pH of less than 7
Bases have a pH
of more than 7
pH 7 is H+ = OH-
every stage on the pH scale is a 10fold increase
so pH 7 has 102 more Hydrogens than pH 9.
Pure water is pH
7
Milk is pH 6
Lemons are pH2
or 3
Bleach is pH 12
Baking soda is pH
9
pH indicators
Some things change colour in the presence
Of an acid or a base
For example
Cabbage juice will turn pink for acid, blue for base
Litmus paper will turn pink for acid, blue for base
Phenolphthalein will turn pink for base and clear for
Acid
Bromothymol blue will turn blue for base and
yellow for acid
Universal indicator will turn many different colours
