Scheme Of Formaldehyde
HCHO
Physical Characters :-
1. Condition → Liquid , Mobile
2. Color → Colorless
3. Odor → Formaline Odor
4. Miscibility :
- H2O → Miscible with H2O
- Litmus Paper → Change from blue to red Comment : Acidic compound due to atmospheric oxidation
- Anhydrous CuSO4 → Change from white to blue Comment : Aqueous solution
General Reactions :-
1. Dry Heat :
- Change in appearance → Boil , Evaporate
- Degree Of Inflammability → Non-inflammable , Non-Smoky So it maybe : Lower aliphatic comp.
- Nitration Test → Not applied
- Odor produced → No change
- Residual Ash → Absent Comment : Non me tallic comp.
2. Action Of Sodalime →
-on cold Not applied
-on hot Not applied
3. Action Of 30% NaOH →
-on cold :No Characteristic Observation
-on hot :No Characteristic Observation (canizaro reaction)
4. Action Of NaHCO3 → No effervescence Comment : Not strong acidic compound
5. Action Of FeCl3 → No Characteristic Observation
6. Action Of C.H2SO4 → No Characteristic Observation
7. Element test : X ( absent ) N( absent ) S( absent )
Special Tests :-
1-Reduction:-
a)reduction of ammonical silver nitrate:- 3 ml of silver nitrate solution + few drops of dil. NaOH solution + Add dil. ammonia solution drop by drop until the formed ppt. of silver oxide is almost redissolved. → add few drops of the aldehyde →heat on a water bath → A silver mirror or black ppt. is formed.
b)Fehling test:-- Reagent : Fehling A + Fehling B ( equal amounts ) → deep blue color
- sample + Na2CO3 solution + drops of Fehling solution → boil in W.B → green solution turns to red ppt
2- Salicylic acid test:-- sample + Salicylic acid+ 2 drops of C.H2SO4 on the wall of the test tube → Crimson red
Scheme Of Acetaldehyde
CH3CHO
Physical Characters :-
1. Condition → Liquid , Mobile
2. Color → Colorless
3. Odor → Disagreeable Odor
4. Miscibility :
- H2O → Miscible with H2O
- Litmus Paper → Change from blue to red Comment : Acidic compound due to atmospheric oxidation
- Anhydrous CuSO4 → change from white to blue Comment : aqueous solution
General Reactions :-
1. Dry Heat :
- Change in appearance → Boil , Evaporate
- Degree Of Inflammability → Non-inflammable , Non-Smoky So it maybe : Lower aliphatic comp.
- Nitration Test → Not applied
- Odor produced → No change
- Residual Ash → Absent Comment : Non me tallic comp.
2. Action Of Sodalime →
-on cold Not applied
-on hot Not applied
3. Action Of 30% NaOH →
-on cold :No Characteristic Observation
-on hot :yellow resin +bad odor Comment : may be aldehyde containing alpha hydrogen (acetaldehyde)
4. Action Of NaHCO3 → No effervescence Comment : Not strong acidic compound
5. Action Of FeCl3 → No Characteristic Observation
6. Action Of C.H2SO4 → No Characteristic Observation
7. Element test : X ( absent ) N( absent ) S( absent )
Special Tests :-
▐ 1-Reduction:-
a)reduction of ammonical silver nitrate:- t 3 ml of silver nitrate solution + few drops of dil. NaOH solution + Add dil. ammonia solution drop by drop until the formed ppt. of silver oxide is almost redissolved. → add few drops of the aldehyde →heat on a water bath → A silver mirror or black ppt. is formed.
b) Fehling test:-- Reagent : Fehling A + Fehling B ( equal amounts ) → deep blue color - sample + Na2CO3 solution + drops of Fehling solution → boil in W.B → green solution turns to red ppt.
2- Na-Nitroprusside test:-- sample + 2 drops of Na-Nitroprusside +10 ml dil NaOH → reddish violet color
3- Iodoform test :- -1 ml sample + 5 ml dil NaOH + iodine solution. ( drop by drop ) → Shake till persistent yellow color → warm in W.B → yellow crystals of iodoform
Scheme Of benzaldehyde
Physical Characters :-
1. Condition → Liquid , Mobile
2. Color → Colorless
3. Odor → bitter almond Odor
4. miscibility
H2O → Immiscible with H2O -heavier
10%NaOH → Immiscible
- NaHCO3 → Immiscible
- dil. HCl → Immiscible
- C.H2SO4 → Immiscible Comment : Neutral comp
general reactions :-
1. Dry Heat :-
- Change in appearance → Boil , Evaporate
- Degree Of Inflammability → Inflammable , Smoky So it maybe : may be aromatic compound or highly unsaturated aliphatic compound
- Nitration Test → sample +conc H2SO4 +conc HNO3 → yellow oily solution with bitter almond odor Comment :-aromatic compound
- Odor produced → No change
- Residual Ash → Absent Comment : Non me tallic compound
2. Action Of Sodalime →
-on cold Not applied
-on hot Not applied
3. Action Of 30% NaOH →
-on cold :No Characteristic Observation
-on hot :white ppt (canizaro reaction)
4. Action Of NaHCO3 → No effervescence. Comment : Not strong acidic compound
5. Action Of FeCl3 → No Characteristic Observation
6. Action Of C.H2SO4 → No Characteristic Observation
7. Element test : X absent S absent N absent
Special Tests :-
1-Reduction:-
a)reduction of ammonical silver nitrate:- t 3 ml of silver nitrate solution + few drops of dil. NaOH solution + Add dil. ammonia solution drop by drop until the formed ppt. of silver oxide is almost redissolved. → add few drops of the aldehyde →heat on a water bath → A silver mirror or black ppt. is formed.
b) Fehling test:-- Reagent : Fehling A + Fehling B ( equal amounts ) → deep blue color - sample + Na2CO3 solution + drops of Fehling solution → boil in W.B → green solution turns to red ppt.
2- Formation Of Phenyl hydrazone :-- sample + Phenylhydrazine solution→ Shake for 2 minutes → white ppt. of phenyl hydrazone
3- Addition Of Na-bisulphite
- sample + Na-bisulpite solution → shake and scratch with glass rod → white ppt
4-oxidation
-0.5 ml of benzaldehyde and 15 ml of saturated KMnO4 solution and 0.5g. of Na2CO3 + conc.HCl+25% sodium sulphite → on cooling benzoic acid crystallies