pH scale &
Neutralization
Acidic, Basic or Neutral? The
answer may just save your
life!
pH
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The pH of a solution is a measure of
the concentration of H+ ions in it.
The greater the H+ concentration is,
the lower the pH is and the more
acidic the solution is
The pH measures how acidic or basic
a solution is.
pH scale
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To indicate pH, a scale ranging from 0 to
14 has been devised.
Solutions with a pH lower than 7 are
described as acidic.
pH scale: Basic
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Solutions with a pH greater than 7 are
basic
A solution with a pH of exactly 7 indicates
that the concentrations of H+ ions and
OH¯ ions are equal. These solutions are
considered neutral.
Neutralization Reactions
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Neutralization is a chemical
reaction between an acid and a base
that takes place in a water solution.
For example, when HCI is neutralized
by NaOH, hydronium ions from the
acid combine with hydroxide ions
from the base to produce neutral
water.
Salts!
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A salt is a compound formed when
the negative ions from an acid
combine with the positive ions from a
base.
In the reaction between HCl and
NaOH the salt formed in water
solution is sodium chloride.
Salts!
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The following general equation
represents acid-base reactions in
water.
Another neutralization reaction
occurs between HCI, an acid, and
Ca(OH)2, a base producing water
and the salt CaCl2.
Neutral!

Another neutralization reaction
occurs between HCI, an acid, and
Ca(OH)2, a base producing water
and the salt CaCl2