Nature of Hydroxides :
According to Gallis if electronegativity of `A` in a hydroxide (`AOH`) is more than `1.7` then it will be acidic in nature whereas it will be basic in nature if electronegativity is less than `1.7`. See Table.
If the value is more than `X_O - X_H`, then that hydroxide will be basic otherwise it will be acidic.
`[text(Polarity of covalent bond) prop text(Difference of electronegativities)]`
`text(Exception :)` Negative `N` is written first in `NH_3` because it became very common from the very beginning. There is no scientific basis for that. Otherwise according to rule it should have been written as `H_3N` in the form of trihydrogen nitride.
`text(Acidic and Basic Nature of Hydroxides of Elements:)` Acidic and basic nature of hydroxide of an element `AOH` depends on ionisation potential of `A`. If ionisation potential of `A` is low then it will give its electron to oxygen easily thus `AOH` will be basic.
`text(Basic Character)`
`ast` `text(Basic Character of element)` `prop` `1/(text(Effective nuclear charge))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Ionisation potential of metal))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Electronegativity of metal))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Oxidation number of metal))`
`ast` `text(Basic Character of element)` `prop` `text(Metallic property)`
`ast` `text(Basic Character of element)` `prop` `1/(text(Size of atom which forms anion (nonmetal))`
`text(Acidic Character)`
`ast` `text(Acidic character of element)` `prop` `1/(text(Atomic size))`
`ast` `text(Acidic character of element)` `prop` `text(Effective nuclear charge)`
`ast` `text(Acidic character of element)` `prop` `text(Electronegativity of metal)`
`ast` `text(Acidic character of element)` `prop` `text(Oxidation number of metal)`
`ast` `text(Acidic character of element)` `prop` `1/(text(Metallic Character))`
`ast` `text(Acidic character of element)` `prop` `text(size of atoms which forms anion)`
If the value is more than `X_O - X_H`, then that hydroxide will be basic otherwise it will be acidic.
`[text(Polarity of covalent bond) prop text(Difference of electronegativities)]`
`text(Exception :)` Negative `N` is written first in `NH_3` because it became very common from the very beginning. There is no scientific basis for that. Otherwise according to rule it should have been written as `H_3N` in the form of trihydrogen nitride.
`text(Acidic and Basic Nature of Hydroxides of Elements:)` Acidic and basic nature of hydroxide of an element `AOH` depends on ionisation potential of `A`. If ionisation potential of `A` is low then it will give its electron to oxygen easily thus `AOH` will be basic.
`text(Basic Character)`
`ast` `text(Basic Character of element)` `prop` `1/(text(Effective nuclear charge))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Ionisation potential of metal))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Electronegativity of metal))`
`ast` `text(Basic Character of element)` `prop` `1/(text(Oxidation number of metal))`
`ast` `text(Basic Character of element)` `prop` `text(Metallic property)`
`ast` `text(Basic Character of element)` `prop` `1/(text(Size of atom which forms anion (nonmetal))`
`text(Acidic Character)`
`ast` `text(Acidic character of element)` `prop` `1/(text(Atomic size))`
`ast` `text(Acidic character of element)` `prop` `text(Effective nuclear charge)`
`ast` `text(Acidic character of element)` `prop` `text(Electronegativity of metal)`
`ast` `text(Acidic character of element)` `prop` `text(Oxidation number of metal)`
`ast` `text(Acidic character of element)` `prop` `1/(text(Metallic Character))`
`ast` `text(Acidic character of element)` `prop` `text(size of atoms which forms anion)`
