Benzaldehyde gives a positive test with Tollen's reagent but not with Benedict's and Fehling's solution. Comment why?

Benedict's solution (Cu⁺² citric acid + base) and Fehling's solution (Cu⁺²  tartaric acid + base) are weaker oxidising agents than Tollen's reagent [Ag(NH3)2]⁺, they oxidise alipharic aldehydes only, but are not capable of oxidising aromatic aldehydes.

Related Questions:

Both glucose and fructose are reducing sugars but sucrose is non-reducing in nature. Why?
Fructose contains a keto group, yet it reduces Fehling solution and Tollen's reagent. Why ?
What is Dunstan's test , How can it use for test Glycerol ?
What is luca's reagent and where is luca's reagent uses ?
What is Victory-Meyer's test and how can distinction between 1°, 2° and 3° alcohols by this ?
Benzaldehyde gives a positive test with Tollen's reagent but not with Benedict's and Fehling's solution. Comment why?
Aromatic amines are lesser basic than aliphatic amines.why ?
Which are the compounds gives positive Tollen's test?
What is Tollen's reagent?
What is Carbylamine test or Isocyanide test ?
What is Hinsberg's reagent and where Hinsberg's test use?
N-Ethyl-N-methyl propanamine does not show optical activity why?

Aromatic amines are lesser basic than aliphatic amines.why ?

Aliphatic amines are more basic in nature than aromatic amines because In aliphatic amines the electron density around N atom increases due to - I effect of alky  group and thus chance for proton attack also Increases.

On the other hand in aromatic amines the electron density around N atom decreases due to withdrawing nature of aromatic ring hence thus chance for proton attack on nitrogen atom decreases.

Related Questions:

Both glucose and fructose are reducing sugars but sucrose is non-reducing in nature. Why?
Fructose contains a keto group, yet it reduces Fehling solution and Tollen's reagent. Why ?
What is Dunstan's test , How can it use for test Glycerol ?
What is luca's reagent and where is luca's reagent uses ?
What is Victory-Meyer's test and how can distinction between 1°, 2° and 3° alcohols by this ?
Benzaldehyde gives a positive test with Tollen's reagent but not with Benedict's and Fehling's solution. Comment why?
Aromatic amines are lesser basic than aliphatic amines.why ?
Which are the compounds gives positive Tollen's test?
What is Tollen's reagent?
What is Carbylamine test or Isocyanide test ?
What is Hinsberg's reagent and where Hinsberg's test use?
N-Ethyl-N-methyl propanamine does not show optical activity why?

What is relative basic strength order 1° amines , 2°amines and 3° amines ? Explain:

Amines are more basic in nature than ammonia because in amines alkyl groups are present, which have +I effect, therefore. They increase electron density on nitrogen atom; therefore, amines can donate electron pair more easy than ammonia. On the basis above conclusion the expected order of basic nature of amines is 3°amine > 2°amine > 1° amine (basis of Inductive effect) in gaseous state) 

But actual order is 2° amine > 1°amine > 3°amine this anomalous behavior of amines is explained as follows:

 Actually basic nature of amines not only depends upon electron density available on nitrogen atom, but also depends upon stability of conjugate acid (Solvation effect) that amines form in aqueous solutions. The stability of conjugate acid in turn depends upon the extent of hydrogen bonding. Greater the extent of hydrogen bonding stronger is the conjugate acid and more is the basic nature of amines. on the basis of stability of conjugate acid (Solvation effect) the expected order of basic nature of amines is 1° amine > 2°amine 3°amine 

But net result of the two opposing factors (Inductive and Solvation effect) the net  basic strength order is as 2°amime > 1° amine > 3°amine.

Related Questions:

(1) Arrange the following in the increasing order of their acid strength : Methyl amine, Dimethyl amine, Aniline, N-methyl aniline (I.I.T, 1988).

(2) What is Carbylamine test or Isocyanide test ?

(3) What is Hinsberg's reagent and where Hinsberg's test use?

(4) Can we prepare aniline by Gabriel – phthalimide reaction?

(5) N-Ethyl-N-methyl propanamine does not show optical activity why?

(6) What is relative basic strength order 1° amines , 2°amines and 3° amines ? Explain:

(7) Amines are more basic than ammonia why?

(8) Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

(9) Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

(10) What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

(11) Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

(12) Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

(13) What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

(14) Why pyridine is more basic than Pyrrole?

(15) Why pyrimidine is less basic than pyridine?

(16) Imidazole is more basic than pyridine? Why?

(17) Biological Important of Imidazole and structure:

(18) Pyridine is almost 1 million times less basic than piperidine? Why?

(19) Cyclohexylamine amine is the stronger base than Aniline? Why?

(20) Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Amines are more basic than ammonia why?

Amines are more basic in nature than ammonia because in amines alkyl groups are present, which have -I effect, therefore. They increase electron density on nitrogen atom, therefore, amines can donate electron pair more easy than ammonia.

Related Questions:

1. What is relative basic strength order 1° amines , 2°amines and 3° amines ? 
2. Explain:Arrange the following in the increasing order of their acid strength : Methyl amine, Dimethyl amine, Aniline, N-methyl aniline (I.I.T, 1988).
3. What is Carbylamine test or Isocyanide test ?
4. What is Hinsberg's reagent and where Hinsberg's test use?
5. Can we prepare aniline by Gabriel – phthalimide reaction?
6. N-Ethyl-N-methyl propanamine does not show optical activity why?
7. What is relative basic strength order 1° amines , 2°amines and 3° amines ? Explain:
8. Amines are more basic than ammonia why?
9. Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?
10. Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?
11. What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?
12. Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?
13. Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?
14. What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?
15. Why pyridine is more basic than Pyrrole?
16. Why pyrimidine is less basic than pyridine?
17. Imidazole is more basic than pyridine? Why?
18. Biological Important of Imidazole and structure:
19. Pyridine is almost 1 million times less basic than piperidine? Why?
20. Cyclohexylamine amine is the stronger base than Aniline? Why?
21. Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Which ketones gives a positive Tollen's test ?

Alpha hydroxy ketones are gives positive Tollen's test because tauotomerise into aldehyde .

Related Questions:

Penta-1,3-diene is more stable than penta-1,4 -diene. Why?

Phenoxide ion is more stable than an alkaoxide. why?

Why does aqueous sodium bicarbonate solution dissolve carboxylic acids but not phenol though they are also acidic ?

Why enol form of Beta Dicarbonyl compound more stable than those of monocarbonyl compounds?

Why enol form of phenol is more stable than its keto isomers?

Reactivity order of Pyrrole, Furan and Thiophene towards Electrophilic substitution :

Phenyl group is known to extract negative inductive effect, but each phenyl ring in biphenyl is more reactive than benzene towards Electrophilic substation. Why?

Chloroform is more acidic than fluoroform why?

Fluorine is more electronegative than chlorine even then, p-flurobenzoic acid is weaker acid than p-chlorobenzoic acid explain ? 

Trifluoroethyl carbocation is less stable than trifluromethyl carbocation why ?

Why is the Tropylium carbocation less stable than the tricyclopropylmethyl carbocation?