Aromaticity Chemistry Of Aromatic Compounds

Step 1: Understanding the structure of Barium tetrachlorocuprate(II).
Barium tetrachlorocuprate(II) refers to a compound where a Ba ion is bonded to a anion. This means that the copper ion is coordinated to four chloride ions. Thus, the correct formula is Ba[CuCl ].

Step 2: Analyzing the options.
(A) Cu[BaCl ]Cl : This is not correct. The formula doesn’t correspond to a tetrachlorocuprate compound.
(B) Ba[CuCl ]Cl : This formula doesn’t reflect the correct coordination of chloride ions around copper.
(C) Cu[BaCl ]: This is incorrect. Copper should be in the center with chloride ions around it, not the other way around.
(D) Ba[CuCl ]: Correct — This is the proper formula for Barium tetrachlorocuprate(II), where Ba is bonded to a anion.

Step 3: Conclusion.
The correct formula is (D) Ba[CuCl ].

Step 1: Recall Gattermann reaction.
In the Gattermann reaction, aromatic diazonium salts are converted into aryl chlorides or bromides using copper powder and corresponding hydrogen halide (HCl/HBr).

Step 2: Differentiate from similar reactions.
Sandmeyer reaction uses cuprous salts (CuCl/CuBr).
Balz–Schiemann reaction gives aryl fluorides using .
Iodination with KI directly replaces the diazonium group without copper.

Step 3: Identify the correct option.
Option (C) uses , which matches the Gattermann reaction conditions.

Step 4: Conclusion.
Thus, option (C) represents the Gattermann reaction.

Step 1: Understanding the molecular geometry.
In , the molecule adopts a bent shape due to lone pair repulsion, and the bond angle is less than the ideal tetrahedral angle of 109.5°.

Step 2: Analyzing the options.
(A) 111.5°: This is incorrect, as the bond angle in is smaller.
(B) 94.8°: Correct — The bond angle in is 94.8°, which is a typical bond angle for bent molecules with lone pair repulsions.
(C) 98.4°: This is incorrect. The bond angle is closer to 94.8°.
(D) 147.5°: This is much too large for a bent structure.

Step 3: Conclusion.
The correct answer is (B) 94.8°.

Step 1: Understanding diazonium reactions.
Diazonium salts are reactive intermediates in organic chemistry that can undergo various reactions, such as substitution with halides, coupling reactions, and reduction.
Step 2: Analyzing the options.
(A) Reaction with potassium iodide: Involves replacement of the diazonium group by iodide.
(B) Reaction with aniline: This reaction does not involve the replacement of the diazonium group, it involves a coupling reaction where the aniline reacts with the diazonium ion.
(C) Reaction with cuprous chloride in HCl: Involves the replacement of the diazonium group by chloride.
(D) Reaction with hypophosphorus acid: This reaction replaces the diazonium group with hydrogen.
Step 3: Conclusion.
The correct answer is (B) Reaction with aniline.

Step 1: Identify the reaction type.
The given reaction is nitration, an electrophilic aromatic substitution reaction.
Step 2: Effect of substituent.
The group present in benzoic acid is a deactivating and meta-directing group.
Step 3: Orientation of substitution.
Due to the meta-directing nature of , the nitro group enters the meta position.
Step 4: Conclusion.
Therefore, the product formed is m-nitrobenzoic acid.

Concept:
In a face-centered cubic (fcc) unit cell, atoms touch along the face diagonal. Thus, relation between edge length and atomic radius is: Step 1: Substitute atomic radius. Since ,
Step 2: Convert into cm.
Step 3: Calculate volume of unit cell.
Step 4: Conclusion.