Oxides and their classification

In this slide you can get about ,what are oxides and how they classify. In this slides I classify the oxides with respect to nature of oxides as well as the oxygen content in it.

1. Oxides are the binary compounds of Oxygen with other element or group of elements . For Example: H2O, N2O2, SiO2, Al2O3, ZnO, CO2 etc. Oxides: Fe2O3

2. Classification of Oxides Depending upon nature and the properties exhibited by compounds, they are classified into: Acidic oxides Basic oxides Amphoteric oxides Neutral oxides

3. Acidic Oxides An acidic oxide is an oxide which when combined with water gives off an acid . SO 3  + H 2 O → H 2 SO 4 B 2 O 3  + H 2 O → 2H 3 BO 3 Non-metals react with oxygen to form acidic compounds of oxides which are held together by covalent bonds . Examples : NO, CO 2

4. Properties & Preparation Of Acidic Oxides C +4 HNO3 → CO2 +4 NO2 +2 H2O Acidic Oxides formed acids when reacts with water. They produce salts when reacting with a base. They are covalent in nature. They work as an oxidizing agent.

5. Basic Oxides A basic oxide is an oxide which when combined with water gives off a base Na 2 O + H 2 O → 2NaOH Metals react with oxygen to give basic compounds of oxygen . These compounds are usually ionic in nature.  Examples : M 2 O 3 , MO 2 , ThO 2

6. CaCO3 −Δ→ CaO+CO2 Basic Oxides formed bases when reacts with water. They produce salts when reacting with an acid. They are ionic in nature. They work as an oxidizing agent. Properties & Preparation Of Basic Oxides

7. Amphoteric Oxides Amphoteric  oxides  are compounds of oxygen which exhibits both acidic as well as basic characteristics.   Acidic characteristics : AL 2 O 3  + 6HCl → AlCl 3 + 3H 2 O Basic characteristics : Al 2 O 3  +2OH– + 3H 2 O → 2[Al (OH) 4 ]–

8. ZnCO3 ___________ >ZnO+CO3 They exhibits both acidic as well as basic characteristics. These oxides when reacting with acid undergoes a neutralization reaction to form water and salt.  Similarly reacts with the alkali to form salt and water. Properties & Preparation Of Amphoteric Oxides

9. Some compounds react with oxygen to form oxides which do not exhibit acidic nor basic characteristics. Such compounds are called as neutral compounds of oxygen . Example : NO, CO. Neutral Oxides

10. Properties & Preparation Of Neutral Oxides  8 HNO3  + 3 Cu → 3 Cu(NO3)2 + 3 H2O + 2 NO They shows neither basic nor acidic properties. They are neutral toward litmus. Under certain condition some neutral oxides do react with acids and bases.

11. Classification of Oxides They are further classified into: Acidic Oxides Basic Oxides Amphoteric Oxides Neutral Oxides They are further classified into: Peroxides Superoxides Dioxides Sub Oxides Compound Oxides Depending upon the oxygen content in the compound ,these oxides are classified into: Normal Oxides: Polyoxides:

12. Normal Oxides: “It is that oxide of oxygen in which the oxidation state of oxygen is normal i.e. -2” For Example: SO 2 CO 2 CaO AL 2O3

13. 4Li+O 2 → 2 Li2O S+O →SO 2 2Ca+O 2 →2CaO It can be acidic It can be basic It can be amphoteric It can be neutral Properties & Preparation Of Normal Oxides

14. It is that oxide of oxygen in which the oxidation state of oxygen is not normal i.e. -2 it contains O-O bond They are further divided into: Peroxide Superoxides Dioxides Sub oxides Compound oxides PolyOxides:

15. “ They are those poly oxides in which the oxidation state of Oxygen is -1” For Example: Na2O2 Structure: Na + O - O- Na + Preparation:  4 Na + O 2  → 2 Na 2 O. 2 Na 2 O + O 2  → 2 Na 2 O 2 Per Oxides (-1) :

16. They have more proportion of Oxygen than normal oxide. They contain peroxide (O-O) -2 bond. On reacting with water or dilute acid they produce H2O2. Na2O2+ 2 H2O → H2O2+ 2 NaOH Properties Of Per Oxides (-1) :

17. “ They are those poly oxides in which the oxidation state of Oxygen is -1/2” For Example: KO 2 Preparation: K + O 2  → KO 2 Super Oxides (-1/2) :

18. They are ionic in nature. They contain superoxide (O-O) -1 bond. They don’t produce H 2 O 2 with acids ,only with water. KO 2 +H 2 O → H 2 O 2 +KOH Properties Of Super Oxides (-1/2) :

19. “These are those oxides which contain two oxygen atoms in it in such a way that each oxygen is directly attached to the central atom”. For Example: MnO 2 , PbO 2 Structure: O=Mn=O , O=Pb=O Dioxides :

20. Properties & Preparation Of Dio xides : Mn+O 2 → MnO 2 They have more proportion of oxygen. They are used as an oxidizing agent. They are most common oxides. They are relatively stable oxides.

21. “These are the oxides that containing the lowest or an unusually small proportion of oxygen.” For Example: Na 2 O Preparation: 2 NaOH + 2 Na → 2 Na 2 O + H 2 Sub oxides :

22. They have the normal oxidation state of Oxygen. Suboxides typically feature extensive bonding between the electropositive element. They often leads to cluster. Properties Of Suboxides :

23. “Compound oxides are metallic oxides that behave as if they are made up of two oxides, one that has a lower oxidation and one with a higher oxidation of the same metal.” For Example: Red lead:  Pb3O4=PbO2+2PbO Ferro-ferric oxide:   Fe3O4=Fe2O3+FeO Compound Oxides :

24. Fe 2+ + 2 Fe 3+ + 8 OH- →Fe3O4 + 4 H2O On treatment with an acid, compound oxides give a mixture of salts. Fe 3 O 4 +8HCl→2FeCl 3 + FeCl 2 +4H 2 O Properties & Preparation Of Compound O xides :