GENERAL METHODS OF PREPARATION OF CARBONYL COMPOUNDS

GENERAL PROPERTIES OF CARBONYL COMPOUNDS

GENERAL PROPERTIES OF CARBONYL COMPOUNDS

Sl. No.	ALDEHYDES ( HCHO, CH3CHO, C6H5CHO )	KETONES ( CH3COCH3, C6H5COCH3, C6H5COC6 H5 )
1	Strong and even mild oxidising agents oxidise them to mono carboxylic acids having the same number of carbon atoms.	Strong oxidising agents only oxidise them to mono carboxylic acids having lesser number of carbon atoms.
2	Restores the original colour of the Schiff’s reagent.	Does not restore the colour of Schiff‘s reagent.
3	Reduces Tollen’s reagent to metallic silver (i.e Gives Silver Mirror)	Does not reduce.
4	Aliphatic aldehydes alone reduce Fehling’s solution to red Cu2O.	Do not reduce.
5	Na / Hg + H2O or LiAlH4 or NaBH4 or H2 / Pt reduce them to 1o alcohols.	Na / Hg + H2O or LiAlH4 or NaBH4 or H2 / Pt reduce them to 2o alcohols.
6	Aldehydes not having α –H atom alone with base undergo Cannizzaro reaction.	Do not undergo
7	Aldehydes having α –H atom alone with base undergo Aldol condensation.	Ketones having α –H atoms alone with base undergo Aldol type condensation.
8	With Grignard reagent HCHO gives 1o alcohol and other aldehydes give 2o alcohols.	Gives 3o alcohols.
9	Forms addition products with NaHSO3	Acetone forms addition products with NaHSO3 while others does not form.
10	HCHO and C6H5CHO forms condensation products with NH3 while CH3CHO forms addition products with NH3	Acetone alone forms condensation products with NH3
11	Aromatic aldehydes alone form Schiff 's base with 1o amines	Do not form Schiff ’s base (or Anils)
12	The aldehydes having CH3CO- group (CH3CHO) undergo Haloform reaction	The Ketones having CH3CO - group (CH3COCH3 and C6 H5COCH3 ) undergo Haloform reaction.
13	Aromatic Aldehydes alone undergo electrophilic substitution reaction at meta-position	Aromatic Ketones alone undergo electrophilic substitution reaction at meta-position
14	Aromatic aldehydes alone undergo Benzoin condensation, Perkin’s reaction, Claisen or Claisen-Schimidt reaction, Knoevenagal reation.	Do not undergo
15	Aliphatic aldehydes alone undergo polymerization	Do not undergo

Aldehydes and Ketones:

1) React with HCN to form cyanohydrin.

2)  Undergo condensation (addition followed by elimination) reaction with ammonia derivatives which contain primary amino group (NH₂OH, NH₂NH₂, NH₂NHC₆H₅, NH₂NHCONH₂) to form compounds containing carbon-nitrogen double bonds.     

                                         OH

                                           |

> C = O +  H₂N - Z ⇆    - C -    → > C = N - Z + H₂O

                                           |

                                          NH-Z
                                        Unstable

Where, Z = -H, Alkyl (-R), Aryl (Ar), -OH, -NH₂, -NH C₆H₅, -NHCONH₂, etc.

3) Clemmenson reduction (or) Wolff-Kishner reduction converts them to hydrocarbons (> C = O group is reduced to – CH₂ – group)

GENERAL METHODS OF PREPARATION OF CARBONYL COMPOUNDS

Extraction of the Metals

S. No.	Metal	Extraction of the Metal / Metallurgy
1	Copper,       Cu	1) Chief ore : Copper pyrites, CuFeS2 2) Concentration : By Froth floatation process 3) Roasting : Volatile impurities S, P, As and Sb are removed as their oxides             S + O2 → SO2            P4 + 5O2 → 2P2O5            4As + 3O2 → 2AsO3    Copper pyrites are partly converted into Sulphides of Cu & Fe        2CuFeS2 + O2 → Cu2S + 2FeS + SO2 (Major Reaction)         2FeS + O2 → 2 FeO + 2SO2  (Minor Reaction) 4) Smelting :           2FeS + 3O2     → 2FeO + 2FeO + 2SO2           FeO + SiO2      → FeSiO3 (slag)           2Cu2S + 3O2   → 2 Cu2O + 2SO2           Cu2O + FeS    → Cu2S + FeO           FeO + SiO2    → FeSiO3 (slag) 5) Bessemerisation :           2 Cu2S + 3O2    → 2 Cu2O + 2 SO2           2 Cu2O + Cu2S  → 6 Cu + SO2           Blister copper contains 98 % Copper 6) Purification : Electrolytic Refining           Anode (+)    : Impure Cu           Cathode (–) : Pure Cu           Electrolyte   : CuSO4 + dil. H2SO4        On passing current, pure Cu is deposited at the Cathode.
2	Chromium,      Cr	1) Chief ore : Chromite (or) Chrome ore, FeO.Cr2O3 2) Concentration : By Gravity separation process 3) Conversion of concentrated Chromite ore into Na2CrO4 (Roasting)                                                      900 – 1000oC      4(FeO.Cr2O3) + 8Na2CO3 + 7O2 (from air) ------------>                                           8Na2CO3 + 2Fe2O3 + 8CO2                                           Soluble       Insoluble 4) Conversion of Na2CrO4 into Na2Cr2O7        2Na2CrO4 + H2SO4 → Na2Cr2O7 + Na2SO4 + H2O 5) Conversion of Na2Cr2O7 into Cr2O3 (Reduction of the dichromate)        Na2Cr2O7 + 3C →  Na2Cr2O4 + 3CO↓        Na2Cr2O4 + H2O → 2NaOH + Cr2O3↓ 6) Reduction of Cr2O3 into Cr : Alumino thermic process         Diagram with labels      Cr2O3 is reduced with Al powder (3:1)      Ignition mixture : BaO2 + Mg powder       The mixture is ignited by a piece of Mg ribbon      Cr2O3 + 2Al → 2Cr + Al2O3 + 468.6 kJ                                          (slag)
3	Zinc,    Zn	1) Chief ore : Zinc blende, ZnS 2) Concentration : By Froth Floatation process 3) Roasting : 2ZnS + 3O2 1200 K→ 2ZnO + 2SO2 4) Reduction : ZnO + C 1673 K→ Zn + CO 5) Purification : Electrolytic Refining      Anode (+)    : Impure Zn      Cathode (–) : Pure Zn      Electrolyte  : ZnSO4 + dil. H2SO4        On passing current pure Zn gets deposited on the Cathode
4	Silver,      Ag	1) Chief ore : Argentite (or) Silver glance, Ag2S 2) Concentration : By Froth floatation process 3) Treatment of the concentrated ore with NaCN: Mac Arthur Forrest’s Cyanide process       Ag2S + 4NaCN → 2 Na[Ag(CN)2] + Na2S 4) Precipitation of Silver      2Na[Ag(CN)2] + Zn → 2Ag↓ + Na2[ Zn(CN)4 ] 5) Purification : Electrolytic Refining      Anode (+)   : Impure Ag      Cathode (–) : Pure Ag       Electrolyte : AgNO3 + 1% HNO3     On passing electricity pure Ag gets deposited at the Cathode.
5	Gold,        Au	1) Chief ore : Sulphide (or) Telluride ore. 2) Concentration : By Froth floatation process 3) Roasting : Volatile impurities S, As and Te are removed as their oxides. 4) Treatment of the concentrated ore with KCN: Mac Arthur Forrest Cyanide process      4 Au + 8KCN + 2H2O + O2 → 4K[Au(CN)2] + 4KOH 5) Precipitation of Gold :       2K[Au(CN)2] + Zn → K2[Zn(CN)4] + 2Au↓ 6) Purification : Electrolytic Refining      Anode (+)    : Impure Au      Cathode (–) : Pure Au       Electrolyte : AuCl3 + 10 – 12% HCℓ     On passing current pure Au gets deposited at the Cathode.

USES OF LOGARITHAMIC TABLE

1. The Periodic table giving Atomic Number &

Chemical Symbols for each element

1. Position of the element in the periodic table ( Group No.____ & period No.____ )

2. Atomic number of the element      \

3. Chemical symbol of the element   /Nuclear Chemistry

4. s-Block elements

5. p-Block elements

6. d-Block elements

7. f-Block elements

8. Lanthanides / Lanthanones / 4f-block elements

9. Actinides / Actinones / 5f-block elements

 10. Atomic weight of the elements for the calculation of  M. Wt & F. Wt

 11. E, Z – Nomenclature

2. The Arrangement of electrons in atoms

1. To write the Electron Dot Formula / Electron Structure

2. Molecular orbital theory – Electronic configuration

3. Comparison of IE using Electronic configuration   \

4. Comparison of EA using Electronic configuration /Periodic Properties

5. Calculation of µ (Paramagnetic moment)

6. Colour of the metal / ion / complex

[d⁰, d¹⁰ – Colourless, d^1-9 – Coloured]

7. Magnetic property of the metal / ion / complex

[d⁰, d¹⁰ – Diamagnetic, d^1-9 – Paramagnetic]

8. Calculation of Effective Nuclear Charge (Z*)

3. Properties of the elements

1. Comparison of IE using values   \

2. Comparison of EA using values   |

3. Comparison of EN using values   |Periodic Properties

4. Comparison of IR using values     |

5. Comparison of CR using values  /

6. To know the oxidation number(s) of  the elements

7. Equivalent weight calculation – Electrochemistry – II

8. Formula Weight & molecular Weight calculation