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Transcript
Phosphates

A phosphate, an inorganic
chemical, is a salt of
phosphoric acid. In organic
chemistry, a phosphate, or
organophosphate, is an
ester of phosphoric acid.
Organic phosphates are
important in biochemistry
and biogeochemistry or
ecology. Inorganic
phosphates are mined to
obtain phosphorus for use
in agriculture and industry.
At elevated temperatures
in the solid state,
phosphates can condense
to form pyrophosphates.
History of Phosphates
 According to author Arthur Toy,
elemental phosphorus was
discovered accidentally in 1669
while an impoverished German
chemist was trying to make gold.
Today phosphorus is an important
part of many of the products that
are indispensable to modern living
and good health.
Geochemistry of Phosphates


Phosphates are the naturally occurring form of the element
phosphorus, found in many phosphate minerals. In
mineralogy and geology, phosphate refers to a rock or ore
containing phosphate ions. Inorganic phosphates are mined
to obtain phosphorus for use in agriculture and industry.
The largest phosphorite or rock phosphate deposits in North
America lie in the Bone Valley region of central Florida, United
States, the Soda Springs region of Idaho, and the coast of
North Carolina. Smaller deposits are located in Montana,
Tennessee, Georgia and South Carolina near Charleston along
Ashley Phosphate road. The small island nation of Nauru and
its neighbor Banaba Island, which used to have massive
phosphate deposits of the best quality, have been mined
excessively. Rock phosphate can also be found in Egypt,
Israel, Morocco, Navassa Island, Tunisia, Togo and Jordan,
countries that have large phosphate mining industries.
Ecology of Phosphates

In ecological terms, because of its important role in
biological systems, phosphate is a highly sought after
resource. Once used, it is often a limiting nutrient in
environments, and its availability may govern the rate
of growth of organisms. This is generally true of
freshwater environments, whereas nitrogen is more
often the limiting nutrient in marine (seawater)
environments. Addition of high levels of phosphate to
environments and to micro-environments in which it is
typically rare can have significant ecological
consequences. For example, blooms in the populations
of some organisms at the expense of others, and the
collapse of populations deprived of resources such as
oxygen can occur. In the context of pollution,
phosphates are one component of total dissolved
solids, a major indicator of water quality.
Ecology of Phosphates
Although phosphorus is a naturally occurring
nutrient, human impacts have increased its
availability
Most waste water treatment plants cannot take
phosphorus out of the water
Chemical Properties
The phosphate ion is a polyatomic ion with the empirical formula
PO3−4 and a molar mass of 94.973 g/mol. It consists of one central
phosphorus atom surrounded by four oxygen atoms in a tetrahedral
arrangement. The phosphate ion carries a negative three formal
charge and is the conjugate base of the hydrogen phosphate ion,
HPO2−4, which is the conjugate base of H2PO−4, the dihydrogen
phosphate ion, which in turn is the conjugate base of H3PO4,
phosphoric acid. It is a hypervalent molecule (the phosphorus atom
has 10 electrons in its valence shell). Phosphate is also an
organophosphorus compound with the formula OP(OR)3. A phosphate
salt forms when a positively-charged ion attaches to the negativelycharged oxygen atoms of the ion, forming an ionic compound. Many
phosphates are not soluble in water at standard temperature and
pressure. The sodium, potassium, rubidium, caesium and ammonium
phosphates are all water soluble. Most other phosphates are only
slightly soluble or are insoluble in water. As a rule, the hydrogen and
dihydrogen phosphates are slightly more soluble than the
corresponding phosphates. The pyrophosphates are mostly water
soluble.

PHOSPHATES IN EVERYDAY LIVING
Phosphorus is a nutrient vital to
human, animal, and plant life. It
is one of the most common
substances in our environment,
naturally occurring in our food,
our water and our bodies. In your
body, phosphorus is present in
your genes, your teeth, and your
bones -- even your muscles work
because of the phosphorus in
adenosine triphosphate.
1. Phosphoric acid-based chemical polishes are used primarily
to chemically polish (brighten) aluminum and aluminum
alloys.
2. Many phosphorus-containing materials are used as flameretardants for textiles, plastics, coatings, paper, sealants and
mastics.
3. "Phosphates and phosphoric acid have many uses in the
treatment of potable (drinking) water.
4. Cleaning solutions with phosphates help clean mildew and
stubborn stains on vinyl siding.
There are a few characteristics that define phosphate properties,
mainly molecular structure and pH (generally in a 1% solution). These
determine the functionality of phosphates that in turn determine how
the phosphates are used. They contribute buffering strength,
sequestering (or chelating) power, dispersion and absorptive
capabilities, and solubility. Phosphates are usually used as compounds
of phosphate ions in combination with one or more common elements,
such as sodium, calcium, potassium, and aluminum. They also offer
benefits as nutrient sources.
Phosphates are classified into several primary groups based on the number of
phosphorus (P) atoms. Each of these groups have functional properties ideal for
many applications.
Orthophosphates
Buffering - detergents, baking
Pyrophosphates
Sequestering - water treatment, metal cleaning
Tripolyphosphates
Dispersant - meat processing, dish detergent
Polyphosphates
Dispersant - kaolin production, processed cheese
Number of P Atoms
Ion
Usual Name
1
PO4-3
Orthophosphates
2
P2O7-4
Pyrophosphates
3
p3O10-5
Tripolyphosphates
>3
PnO(3n+1)-(n+2)
Polyphosphates
Phosphate products are a significant part of everyday living. In addition to their
versatility, government authorities also recognize them as safe for worker
exposure and handling and for use in the home. In addition to their versatility,
phosphates are recognized by government authorities as safe for worker
exposure and handling and for use in the home.
In many water bodies, phosphorus is the limiting nutrient and controlling its
level is an important step in preventing eutrophication. In most areas, most of
the phosphorus comes from the environment itself, and only a fraction (about a
third) from consumer products.
Phosphates are important in our daily lives, as well as in
Geology, Chemistry, etc. We should use it properly, don’t
abuse the use of it for it will cause us more than the money we
used to get it