Tag: nitroarenes- preparation and properties

Questions Related to nitroarenes- preparation and properties

Benzene on reaction with conc. $HNO _{3}$ in presence of conc. $H _{2}SO _{4}$ followed by the treatment of $Cl _{2}$ in presence of $FeCl _{3}$, it gives :

chemistry organic nitrogen compounds nitroarenes- preparation and properties nitro compounds types of organic reactions

  1. $2 - chloro - 1 - nitrobenzene$

  2. $1 - chloro - 3- nitrobenzene$

  3. $3 - chloro - 1- nitrobenzene$

  4. A mixture of $2 - chloro$ and $4 - chloro - 1 - nitrobenzene$

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Correct Option: C
Explanation:

3-Chloro-1-nitrobenzene
Nitro substituents have positive charge on the atom bonded to ring. So the like charges repel each other at ortho and para position as compared to meta substitution. So meta position is favored at 3 chloro in the ring.

When nitrobenzene is treated with $Br _{2}$ in presence of $FeBr _{3}$ the major product formed is m - bromonitrobensene. Statement which is related to obtain the m - isomer is:

chemistry organic nitrogen compounds nitroarenes- preparation and properties nitro compounds types of organic reactions

  1. The electron density of meta carbon is more than that on ortho and para positions

  2. Loss of aromaticity when $Br^{+}$ attacks at the ortho and para positions and not at meta position

  3. Easier loss of $H^{+}$ to regain aromaticity from the meta position than from ortho and para positions

  4. None of the above

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Correct Option: A
Explanation:

The exact influence of a given substituent is seen as its interactions with the delocalized positive charge on the benzonium intermediate generated by bonding to the electrophile at each of the three substitution sites. Nitro groups have a positive charge on the atom bonded to the aromatic ring. Like charges of two groups are destabilized by charge repulsion so meta-products predominate as compared to others.

Nitrobenzene is used for making aniline, an important chemical used in:

chemistry organic nitrogen compounds nitroarenes- preparation and properties nitro compounds types of organic reactions

  1. the making of glue

  2. the dyeing industry

  3. the crimping of wool

  4. fast-drying varnish

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Correct Option: B
Explanation:
Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Its main use in dyeing industry is as a precursor to indigo, the blue of blue jeans.

A compound X of formula $\displaystyle C _{2}H _{5}NO _{2}$ on treatment with $\displaystyle (HNO _{2}+HCl)$ gives off an inactive gas Y and form Z when heated with soda lime X gives A $\displaystyle (CH _{5}N)$ soluble in acid Find the true statements among the following.

chemistry organic nitrogen compounds nitroarenes- preparation and properties nitro compounds types of organic reactions

  1. A answers carbylamine test

  2. X is an amino acid

  3. Y is $\displaystyle CO _{2}$

  4. Z is a hydroxyl acid

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Correct Option: B,D