Suffix – “ic-acids” , ‘us-acids” :

The preffix “us” use for the those oxy acids which have one of the lower common oxidatation state while preffix “ic” use for those oxy acid have one of the higher oxidation state for example the common positive oxidation state of  nitrogen is its oxy acid HNO₂ is (+3) and HNO₃ is (+5) so  HNO₂ named as nitrous acid while HNO₃ is named as nitric acid. And  other example of Sulphurous acid H₂SO₃(+4) and sulphuric acid H₂SO₄(+6).

 Related Questions:

What are "pyro" oxy acids?
Why SF6 behave inert towards hydrolysis?
What are the SESQUI OXIDES ? give the examples.
Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].
Although Sulphur contain vacant d-orbital but SF6 does not under go hydrolysis. Why ?
CCl4 can not be hydrolysed but SiCl4 can be. Why?
Silianol (SiH3OH) is more acidic than methanol (CH3OH) why?

Pyro-oxy acids:

The term "Pyro" use for those oxy acid which are formed by removal of one water molecule from two molecules of same oxy acid and resulting product is also an oxy acid then the product acid is named with prefix "Pyro"

For Examples:

H3BO3 (√), H2CO3 (√), H4SiO4 (√), HNO3 (×), HPO3 (√), HPO4 (√), H2SO4 (√), HCl4 (×)

(×) "Pyro" form not possible.

(√) "Pyro" form possible.

(1) In general those oxy acids are formed “pyro” acid which contains atleast two hydrogen atoms.

(2) In general all the “pyro” oxy acids contain oxy-linkage except "pyro sulphurous acid"

 Related Questions:

What are "pyro" oxy acids?

What are "Ortho" or "Meta" oxyacids?

Why SF6 behave inert towards hydrolysis?

What are the SESQUI OXIDES ? give the examples.

Arrange in increasing order of extent of hydrolysis [ CCI4, MgCI2, AICI3, PCl5, SiCI4].

Although Sulphur contain vacant d-orbital but SF6 does not under go hydrolysis. Why ?

CCl4 can not be hydrolysed but SiCl4 can be. Why?

Silianol (SiH3OH) is more acidic than methanol (CH3OH) why?