Sesqui Oxides

The oxides in which number of oxygen atoms pet central atoms is found to be 3/2 .And it may be ionic, covalent or missed oxides.Mostly M₂O₃ type Oxides (Corundum structure) are sesqui Oxides.  Where M⁺²= Al, Ga, Ti, V, Cr, Fe, The etc.

Examples , B₂O₃, N₂O₃, Al₂O₃ ( covalent oxide) Fe₂O₃ (ionic oxide) Pb₂O₃ (mixed oxide)

Super Oxides

The oxides in which oxidati state of oxygen atom always -1/2, and super oxides are always ionic and paramagnetic.

For examples KO₂ , PbO₂, (NH₄)O₂ etc.

KO₂ => k+[O-O]-. Have following character

Bond pair -2

Lone pair -2

Hybri- sp2, linear non planner and bond angle not applicable.

Neutral Oxides

The are  oxides of non metals which are neither acidic nor basic in nature or these are not  react  with acids or bases for examples.

                                 CO, NO, N₂O, H₂O and OF₂ etc.

The Usanovich Acid- Base Concept

 According to this concept  acids are any chemical species which react with bases and gives cations or accept anions or electrons.

Similarly Bases are a chemical species which react with acids and gives anions or electrons or cations

Hard and Soft  acids and bases:

Lux- Flood Acid-Base Concept:

The Lux-Flood concept is given by Lux in 1929 and supported by Flood in 1947. Lux-Flood concept is based on oxide ion acceptor and donor tendency.

Lux-Flood bases:  According to this concept bases are those species which can donate oxide ions examples.

Lux-Flood Acids:  According to this concept Acids are those species which can accept oxide ions.

Chemical Reactions according Lewis acid-base concept:

Acid-base reaction in term Lux-Flood acid and base is a specific reactions in which oxide ions are mainly use in molten form or at high temperature.

Amphoteric Nature of Oxides as per Lux-Flood Concept:

Acidic Nature of Xenon fluoride as per Lux-Flood Concept:

According to Lux –Flood concept Xenon fluorides accept oxide ions from other compounds and insert fluorides ions in its place.

For examples

The Order of decreasing Lux-Flood acidity of Xenon Fluorides is given as:

Limitations of Lux-Flood Acid –base Concept:

(1) It is dealing with anhydrous reaction in fused molten oxides and  other high temperature reactions found in metallurgy and ceramics.

(2) When Lux-Flood, acidic and basic of oxide react with water gives corresponding acid and base.

Limitations of Lux-Flood Acid –base Concept:

(1) Base must contain oxide ion and acid must have accept oxide ions.

(2)It fails to explain reaction without  metal ions