Oxides and oxyacids of phosphorous

Phosphorus forms a number of oxoacids as given in below table.

Oxoacids of phosphorus

NameFormulaOxidation state of P
Hypophosphorus acidH3PO2+1
Phosphorus acidH3PO3+3
Hypophosphoric acidH4P2O6+4
Orthophosphoric acidH3PO4-
Diphosphoric acid (Pyrophosphoric acid)H4P2O7+5
Metaphosphoric acidHPO3+5
Peroxophosphoric acidH3PO5+7

Among the oxoacids of phosphorus, orthophosphoric acid is the most important and is used in the manufacture of phosphate fertilizers.

The structures of oxoacids of phosphorus are systematically given ahead:

structure of oxoacids of phosphorus

The formulae of oxoacids of P can be remembered as:

The prefix

a) meta acid is used for the acid obtained by the loss of one water molecule.

b) pyro acid is used for the acid obtained by heating two molecules with loss of one water molecule.

c) hypo is generally used for the acid having lower oxygen content than the parent acid.

However. it may be noted that metaphosphoric acid does not exist as simple monomer; it exists are cyclometaphosphoric acid or polymetaphosphoric acid.

trimetaphosphoric acid
polymetaphosphoric acid

15 comments:

Anonymous said...

THIS WAS SO HELPFUL! Thank you so much!

Unknown said...

Thanks this i a good way to learn and understand

is there any same type of method to learn sulfur acids also

Unknown said...

Thanks this i a good way to learn and understand

is there any same type of method to learn sulfur acids also

Unknown said...

thank you so much this is easy to take as short notes

Shrey said...

Ar u mad how can u say O.S of phosphorus as +7 in H3PO5
Here P has +5 O.S due to peroxide

Shrey said...

Ar u mad how can u say O.S of phosphorus as +7 in H3PO5
Here P has +5 O.S due to peroxide

Shrey said...

Ar u mad how can u say O.S of phosphorus as +7 in H3PO5
Here P has +5 O.S due to peroxide

Shrey said...

Ar u mad how can u say O.S of phosphorus as +7 in H3PO5
Here P has +5 O.S due to peroxide

Shrey said...

Ar u mad how can u say O.S of phosphorus as +7 in H3PO5
Here P has +5 O.S due to peroxide

Piyumi Jayawardana said...

Thank you so much. This is so clearly presented ����

Anonymous said...

How can Phosphorus have +7 oxidation state when phosphorus belongs to VA?

Unknown said...

No it is +7 only
3(1)+x+5(-2)=0
3+x-10=0
X+3=10
X=10-3=+7

Unknown said...

No it's +7
3(1)+x+5(-2)=0
3+x-10=0
X=10-3
X=+7

Unknown said...

It is chemistry and not simple maths. There are concepts behind o.s . The max o.s of phosphorus can only be +5. And iy can never be +7. Due to formation of peroxide bond. +5 o.s is right.

Unknown said...

This is chrmistry and not just maths. Use your brains. How is it even possible for phosphorous to have a +7 o.s. it can attain a max value of +5. And here your maths fails because of peroxide bond formation.