Tag: amines

Quizzes (2) Questions (25)

Questions Related to amines

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 of $0-5^\circ C$- :

  1. $CH _{3}CH _2N\equiv N\left. \right \} ^\oplus Cl^{-} $
  2. $CH _{3}-C(CH _{3}) _{2}-N\equiv N\left. \right \} ^\oplus Cl^{-} $
  3. $CH _{3}-N\equiv N\left. \right \} ^\oplus Cl^{-} $
  4. $(CH _{3}) _{3}C-N\equiv N\left. \right \} ^\oplus Cl^{-} $
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The diazonium salt  $CH _{3}-N\equiv N\left.  \right } ^\oplus Cl^{-}$ obtained by treatment of methylamine with nitrous acid is relatively stable at $0-5^\circ C$.

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 $\displaystyle 0-5^{\circ}$C?

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

Diazonium salts obtained from aliphatic primary amines are unstable. Those obtained from aromatic primary amines are relatively stable.
Benzene diazonium chloride $(\displaystyle C _{6}H _{5}-N\equiv N \left.  \right }^{\oplus }Cl^{-})$ is obtained from aromatic primary amine. Hence, it is relatively stable.

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

Which of the following statements are correct? 

  1. Aryldiazonium ions are more stable than alkyldiazonium ions.

  2. Electron release from the ortho- and para-positions of the ring stabilises the aryldiazonium ion.
  3. The increased stability of aryldiazonium is due to the great difficulty of forming $\displaystyle { Ar }^{ \oplus }$ as compared to $\displaystyle { R }^{ \oplus }$.

  4. Alkyldiazonium is more stable than aryldiazonium ion.
Reveal answer Fill a bubble to check yourself
A,B,C Correct answer
Multiple choice chemistry amines introduction to diazonium salts structure, preparation and physical properties of diazonium salts diazonium salts

Arrange the following resonating structure according to their contribution towards resonance hybrid?
(a) $CH _2=\overset {\oplus}{N}=\overset {\ominus}{N}$ (b) $\overset {\ominus}{C}H _2-N=\overset {\oplus}{N}:$ (c) $\overset {\oplus}{C}H _2-\underset {. .}{N}=\overset {\ominus}{N}$ (d) $\overset {\ominus}{C}H _2-\overset {\oplus}{N}\equiv \overset {. .}{N}$

  1. a > d > c > b

  2. b > a > c > d

  3. a > c > b > d

  4. d > a > b > c
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
The correct order of the contribution of resonating structure towards resonance hybrid is
$\displaystyle a (CH _2=\overset {\oplus}{N}=\overset {\ominus}{N}) > d (\overset {\ominus}{C}H _2-\overset {\oplus}{N}\equiv \overset {. .}{N}) > c (
\overset {\oplus}{C}H _2-\underset {. .}{N}=\overset {\ominus}{N}
) > b (\overset {\ominus}{C}H _2-N=\overset {\oplus}{N}:)$
a and d have higher contribution as they have less charge separation.
b and c have lower contribution as they have more charge separation.