For unsaturation -C=C-
A)
1)
Discharges bromine solution to colourless without evolving HBr
By adding one molecule of Br/ double bond.
2)
Discharges alkaline potassium permanganate colour (Baeyer?s reagent).
® (Purple to colorless)
B) Adds hydrogen
ALCHOHOLS
A)
1) Forms esters with acid, acid chlorides and acid anhydrides.
2) Red colour with ceric ammonium nitrate.
3) Evolves brisk effervescence of H2
B) 1) Give alkyl halides with hydrogen halides.
2) Give alkyl halides along with Hcl gas and POCl3 with Pcl5 or Hcl and SO2 with SOCl2.
3) On dehydration gives ethers and olefins (alkenes)
Also alcohols dissolve in cold sulphuric acid (by this it is distinguished from alkanes and alkyl halides). Alcohols do not decolorize Br in CCl4. hence show that they are saturated comp?s.
Alcohols are distinguished from every other compound by--------
Their oxidation by chromic anhydride CrO3.® It turns the clear orange sol green.
R-OH + HCrO4- ® opaque, blue-green
(1* or 2*) (Clear orange)
Its one of their exclusive rxn.
Primary secondary and tertiary alcohols are distinguished to each other by the Lucas test. Lucas reagent is (anhydrous ZnCl2 and conc. Hcl)
----Tertiary alcohols give turbidity immediately.
----Secondary alcohols react within 5 mins.
----Primary alcohols don?t react at all.
PHENOLS
Soluble in alkali
Turns blue litmus red
No effervescences of CO2 with NaHCO3 sol.
Undergo Riemer tiemann reaction.
Gives red color with Ceric ammonium nitrate.
------Phenols are also distinguished by their acidity. They are more acidic than water and other alcohols.
ACIDS
Turns blue litmus red
Gives effervescence of CO2 with sodium bicarbonate solution
Form esters with alcohols in the presence of conc. sulphuric acid.
On decarboxylation loses CO2 and forms hydrocarbon.
Distillation of their calcium salts gives ketones.
Distillation of their calcium salts with calcium formate gives aldehydes.
ALDEHYDES AND KETONES
They form crystalline precipitate of 2,4-dinitro phenylhydrazines with 2,4-dinitrophenyl hydrazine sols. Its exclusive for aldehydes and ketones.
Similarly they form oximes with hydroxylamine?s (NH2-OH) semicarbazones and semicarbazide (NH2-NH-CO-NH2) and phenyl hydrazones with phenylhydrazines (C6H5-NH-NH2).
For aldehydes only
Reduces red color of fehlings sol to give® red ppt of copper oxide.
Reduces tollen?s reagent to give® black ppt of metallic silver (silver mirror).
Restore pink color of Schiff?s reagent.
Give red ppt with benedicts solution.
Aromatic aldehydes and also formaldehyde undergo CANNIZARO rxn with strong alkali ® alcohol and acid.
Also undergo CLEMMENSEN reduction.(By means of amalgated Zn and Hcl converts ?CHO to ?CH3).
For ketones only
They don?t respond to Fehling?s, tollen?s Schiff?s and Benedict?s tests.
They are oxidized to acids containing fewer carbon atoms than the original ketone.
Methyl ketones undergo iodoform rxn. (CH3-C=0 grp)
AMINES
Carbylamine?s rxn®
It?s given exclusively by primary amines. the mix of primary amine.
R-NH2 + CHCL3 + Alc (KOH) ® R ¾NºC + KCl + H20
(Isocyanides)®Foul smell
Reaction with nitrous acid®
Aliphatic primary amines in Hcl form alcohols with nitrous acid (NaNO2 + Hcl) and evolve N2 gas.
Tertiary amines do not react with nitrous acid.
Primary, secondary and tertiary amines can be distinguished by HINSBERG?S test.
3) Aromatic primary amines undergo diazotisation while secondary and tertiary don?t.
It?s a Summary of some?analytical rxn?s of organic chemistry?which may be used to solve problems based on chemical rxn?s
Hope it?s useful...
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