Tag: amines

Quizzes (2) Questions (25)

Questions Related to amines

Multiple choice chemistry amines chemical reactions of diazonium salts chemical properties of diazonium salts diazonium salts

Sandmeyer reaction is better than Gattermann reaction because:

  1. sandmeyer reaction uses salt of copper while Gattermann reaction uses copper powder.

  2. only one salt is produced in Sandmeyer reaction while Gattermann reaction produces two salts.

  3. sandmeyer reaction gives better yield than Gattermann reaction.

  4. all of the above.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sandmeyer gives a higher yield.So,it is better than Gattermann reaction.

Multiple choice chemistry amines chemical reactions of diazonium salts chemical properties of diazonium salts diazonium salts

Which of the reaction would you choose for the most beneficial conversion shown below?
$ArN _2^+X \rightarrow ArCl$

  1. Sandmeyer Reaction

  2. Gattermann Reaction
  3. Directly reacting with $HCl$

  4. Both A and B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Sandmeyer and Gattermann reactions are two processes used mostly for the above conversion.But Sandmeyer is more beneficial as it gives a higher yield.

Multiple choice chemistry amines chemical reactions of diazonium salts chemical properties of diazonium salts diazonium salts

3- Amino-2, 3-dimethyl butan-2-ol when treated with $ NaNO _{2}/HCl$ gives product (X). (X) on treatment with $LiAlH _{4}$ forms (Y). (Y) on heating with $conc. H _{2}SO _{4}$ forms (Z). The molecular weight of (Z) is :

  1. 81

  2. 82

  3. 83

  4. 84
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

3- Amino-2, 3-dimethyl butan-2-ol is diazotized with sodium nitrite in presence of HCl at low temperature to obtain 3,3-dimethylbutan-2-one (compound X).
The carbonyl group is then reduced to obtain 3,3-dimethylbutan-2-ol (compound Y). This is followed by dehydration to obtain 2,3-dimethylbut-2-ene (compound Z).

Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

Which of the following compounds will not undergo azo coupling reaction with benzene diazonium chloride?

  1. Aniline

  2. Phenol

  3. Anisole

  4. Nitrobenzene
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Diazonium cation is weak electrophile and hence it reacts with electron rich compounds containing electron donating groups such as $-OH$, $-NH _2$ and $OCH _3$ groups and not with compounds containing electron withdrawing groups such as $-NO _2$ etc.


Hence,option D is correct.

Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

Which of the following diazonium salt is relatively stable at $0-{ 5^0 }^{ }C$?

  1. ${ CH } _{ 3 }-N\equiv N{ \} }^{ \oplus }C{ l }^{ - }$
  2. ${ \left( { CH } _{ 3 } \right) } _{ 2 }CH-N\equiv N{ \} }^{ \oplus }{ Cl }^{ - }$
  3. ${ C } _{ 6 }{ H } _{ 5 }-N\equiv N{ \} }^{ \oplus }{ Cl }^{ - }$
  4. ${ \left( { CH } _{ 3 } \right) } _{ 3 }C-N\equiv N{ \} }^{ \oplus }{ Cl }^{ - }$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The $+I$ effect which stabilizes the ${ N }^{ + }$ion is in the following order ${ C } _{ 6 }{ H } _{ 5 }-<{ CH } _{ 3 }-<{ \left( { CH } _{ 3 } \right)  } _{ 2 }-<{ \left( { CH } _{ 3 } \right)  } _{ 3 }$

$\therefore $ The ${ \left{ { \left( { CH } _{ 3 } \right)  } _{ 3 }C-N\equiv N \right}  }^{ + }{ Cl }^{ - }$ is most stable

Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

Which of the following is an Incorrect statement about benzenediazonium chloride?

  1. It is prepared by the reaction of aniline with nitrous acid at 273-278 K

  2. It is a colourless crystalline solid

  3. Alkyl diazonium salts are more stable than arenediazonium salts

  4. Benzene diazonium fluoroborate is water insoluble & stable at room temperature
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Arenediazonium salts are much more stable than alkyl diazonium salts due to the dispersal of the positive charge over the benzene ring via resonance. Alkyl diazonium salts, lacking this resonance stabilization, decompose readily even at low temperatures.

Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

For the successful diazotisation of arylamines, how many mole of mineral acid $(HCl \quad or \quad H _2SO _4 )$ are required for each mole of the amine?

  1. 1

  2. 2

  3. 3

  4. 4
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For successful diazotization, 3 moles of mineral acid are required per mole of amine: 1 mole to convert the amine to its salt, 1 mole to generate nitrous acid from sodium nitrite, and 1 mole to maintain a highly acidic medium to prevent coupling reactions.

Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

In an analytical determination of arsenic, a solution containing arsenious acid, $ H _{3}AsO _{4},$ KI and a small amount of starch is electrolysed. The electrolysis produces free $I _{2}$ from $ I^{-}$ ions and the $ I _{2}$ immediately oxidizes the arsenious acid to hydrogen arsenate ion, $ HAsO _{4}^{2-}.$
$ I _{2}+H _{3}AsO _{3}+H _{2}O \rightarrow 2I^{-} + HAsO _{4}^{2-}+4H^{+}$
When the oxidation of arsenic is complete, the free iodine blue colour. If during a particular run, it takes 96.5 s for a current of 10.0 mA to give an end point (indicated by the blue colour),how many g of arsenic are present in the solution. (As = 75)

  1. $ 6.3 \times 10^{-4} g$
  2. $1.26 \times 10^{-4}g$
  3. $ 3.15 \times 10^{-5}g$
  4. $ 6.3 \times 10^{-5}g$
Reveal answer Fill a bubble to check yourself
D Correct answer