Oxygen Family-properties & some important compounds

1. OXYGEN FAMILY
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 1
Dr Bincy Joseph
ASSISTANT PROFESSOR
DEPARTMENT OF CHEMISTRY
ST. MARY’S COLLEGE, THRISSUR

2. OXYGEN FAMILY(Chalcogens) –GENERAL PROPERTIES
Property O S Se Te Po
Atomic
Size(pm)
66 104 117 137 146
IE(Kjmol-1) 1310 999 941 869 813
Electronegativi
ty
3.5 2.5 2.4 2.1 2.0
Metallic
Character
Non metal Non metal metalloid metalloid Metal
Oxidation State -2,-1,+1,+2 -2,+2,+4,+6 -2,+2,+4,+6 -2,+2,+4,+6 +2,+4
Allotropy Ozone(03),d
ioxide(O2)
Rhombic,Mi
noclinic,Pla
stic
Rhombic,Mo
noclinic,grey
Crystalline
Atomicity
B.P(oC)
O2
-163
S8
445
217 452 247
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur
2

3. Some compounds
1.Binary Hydrides(H2E)
Binary
Hydrides
H2O H2S H2Se H2Te H2Po
Bond Angle 104.5 92.1 91 90 88
B.P 100 -60 -41 -2.3 -
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 3

4. 2.Oxides
S Se Te Po
S2O SeO2
SeO3
TeO2
TeO3
PoO
PoO2
SO
SO2
SO3
S2O7
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 4

5. Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 5
Structure of SO2 Molecule-Angular Sp2
Hybridisation
Structure of SO3 Molecule-Triagonal
Planar Sp2 Hybridisation

6. Oxoacids and Peroxoacids
 Sulphurous Acid, H2SO3 pk1=1.79
 Sulphuric Acid, H2SO4 pk1=-2
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 6

7. Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 7
 Pyrosulphuric Acid/Disulphuric acid/Oleum
H2S2O7
 Thiosulfuric acid, H2S2O3 pk1=0.6

8. Peroxoacids
 Caro’s Acid-H2SO5 (peroxomonosulphuric Acid)
 Marshalls Acid-H2S2O8 (peroxodisulphuric Acid)
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 8

9. Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 9
Oxoacids of S containing S-S linkage
 Dithionous Acid (H2S2O4)
 Dithionic Acid(H2S2O6)

10. Ozone(Stratosphere)
 3O2 2O3 , H = +284 KJ (silent electric discharge)
Properties
 Pale blue gas, slightly soluble in water, more soluble in non polar solvents like
CCl4
 Chemical properties
 Decomposition
2O3 3O2 H = -284 KJ
 Oxidizing Action
O3 O2+O
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 10

11. Action with metals, non metals &
metalloids
 2Hg + O3 Hg2O + O2 (Ag)
 S8 + 24O3 + 8H20 H2SO4 + 24O2
 2As + 5O3 + 3H2O 2H3AsO4
 PbS + 4O3 PbSO4 + 4O2
 2FeSO4 + H2SO4 + O3 Fe2(SO4)3 + H2O + O2
 2KI + H2O + O3 2KOH + I2+ O2
 2HCl + O3 Cl2 + H2O + O2
 Action with compounds without evolution of O2 (SO2 SO3)
 Bleaching Action
 With Peroxides (H2O2 + O3 H2O + O2
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 11

12. Addition to unsaturated Compounds-Ozonide
Formation
 CH3-CH=CH2 + O3 CH3CHO + HCHO
 Propyne
Uses
 Germicide and disinfectant
 Bleaching agent
 Oxidising agent (manufacture of Pot Permanganate & silk)
 Ozonolysis
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 12

13. Hydrogen Peroxide
 Preparation from sodium peroxide and dil sulphuric acid (Merck’s process)
 Na2O2 + H2SO4 Na2SO4 + H2O2
Manufacture
 Electrolysis (sulphuric acid to oleum + water )
 H2S2O8 + 2H2O H2O2 + 2 H2SO4
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 13

14. Chemical Properties
1.Decomposition
 2H2O2 2H20 + O
2.Acidic nature-weak dibasic acid
 NaOH + H2O2 NaHO2+ H2O
 2NaOH + H2O2 Na2O2 + 2H2O
3.Oxidizing Action(Acidic and Alkaline media)
H2O2 + 2H+ +2e- 2H2O
H2O2 +OH- +2e- 3OH-
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 14

15. Acidic Medium
 Ferrous to ferric (FeSO4 + H2SO4 +H2O2 Fe2(SO4)3 + H2O
 Lead sulphide to lead sulphate (Pbs + 4H2O2 PbSO4
 Pot iodide to iodine
Basic Medium
Ferrous to ferric
Nitrite to nitrate
Formaldehyde to formic acid
Benzene to phenol
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 15

16. Reducing Properties(acidic and basic medium)
 Addition reaction
Uses
 Disinfectant
 Antiseptic
 Bleaching agent
 Antichlor
 Propellant
 Green chemistry
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 16

17. Sulphuric Acid
 Manufacture- Contact Process
High Boiling Point-intermolecular Hydrogen Bonding
Chemical Properties
1.Strong dibasic acid
2.Dehydrating Action
3.Oxidising Action
4.Action with salts
5.Action with PCl5
6.With Aromatic Compounds
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 17

18. Uses
 Manufacture of Fertilizers
 Manufacture of Pigments
 Manufacture of pharmaceuticals
 Detergent industry
 Metallurgical applications
 Electroplating
 Cellulose products
 Important lab reagent
 Manufacture of various chemicals-nitric acid, phosphoric acid, metal sulphates etc
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 18

19. References
 B.R Puri,L.R Sharma & K C Kalia – Principles of Inorganic Chemistry
 J D Lee ,Concise Inorganic Chemistry.
Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 19

20. Oxygen Family,Dr.Bincy Joseph,St.Marys college,Thrissur 20
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