Question

أربعة مركبات عضوية. $C_7H_6O_3$ : (A) المركب $C_6H_6O$ : (B) المركب $CH_4O$ : (C) المركب $C_3H_6O_2$ : (D) المركب فأي مما يلي يُعد صحيحًا ؟

• A. المركب (B) يتفاعل مع المركب (C) لتكوين مركب عازل للحرارة.
• B. المركب (A) يتفاعل مع المركب (C) لتكوين ألياف الداكرون.
• C. التحلل الحامضي للمركب (D) يُعطي المركب (B).
• D. يتفاعل المركب (A) مع المركب (C) ويعطى زيت المروخ.

Answer 1

Answer: (D)

يتفاعل المركب (A) مع المركب (C) ويعطى زيت المروخ.

Answer 2

The problem asks to identify the correct statement among four options regarding four organic compounds. First, we need to identify the most probable structures for the given molecular formulas.

Compound Identification:

• Compound (A): $C_7H_6O_3$
  This formula strongly suggests an aromatic compound with a carboxylic acid group and a hydroxyl group. The most common compound fitting this description and involved in typical reactions is Salicylic acid (2-hydroxybenzoic acid). Its structure is a benzene ring with a -COOH group and an -OH group ortho to each other.
  SMILES: O=C(O)c1ccccc1O
• Compound (B): $C_6H_6O$
  This formula is characteristic of Phenol ($C_6H_5OH$), which is a benzene ring directly bonded to a hydroxyl group.
  SMILES: Oc1ccccc1
• Compound (C): $CH_4O$
  This formula represents Methanol ($CH_3OH$), the simplest alcohol.
  SMILES: CO
• Compound (D): $C_3H_6O_2$
  This formula could be a carboxylic acid (Propanoic acid, $CH_3CH_2COOH$) or an ester (e.g., Methyl acetate, $CH_3COOCH_3$; Ethyl formate, $HCOOCH_2CH_3$). Its specific identity is not crucial as the statement involving it will be evaluated.

Evaluation of Statements:

1. المركب (B) يتفاعل مع المركب (C) لتكوين مركب عازل للحرارة.
   (Compound (B) reacts with Compound (C) to form a heat insulating compound.)

   • (B) is Phenol. (C) is Methanol.
   • Phenol reacts with formaldehyde (HCHO), not methanol ($CH_3OH$) directly, to form Bakelite (a phenol-formaldehyde resin), which is a heat insulator. While methanol can be oxidized to formaldehyde, the statement implies a direct reaction between phenol and methanol. Therefore, this statement is incorrect.

2. المركب (A) يتفاعل مع المركب (C) لتكوين ألياف الداكرون.
   (Compound (A) reacts with Compound (C) to form Dacron fibers.)

   • (A) is Salicylic acid. (C) is Methanol.
   • Salicylic acid reacts with methanol to form Methyl Salicylate through esterification.
   • Dacron (Polyethylene terephthalate, PET) is a polyester formed by the condensation polymerization of terephthalic acid and ethylene glycol. This reaction does not involve salicylic acid or methanol. Therefore, this statement is incorrect.

3. التحلل الحامضي للمركب (D) يُعطي المركب (B).
   (Acidic hydrolysis of Compound (D) gives Compound (B).)

   • (D) is $C_3H_6O_2$. (B) is Phenol ($C_6H_6O$).
   • Hydrolysis of a $C_3H_6O_2$ compound (e.g., an ester or carboxylic acid) cannot yield a $C_6H_6O$ compound like phenol. Hydrolysis typically breaks down a molecule into smaller components (an acid and an alcohol/phenol from an ester, or it doesn't apply to a carboxylic acid in this context to give phenol). The carbon count is also inconsistent. Therefore, this statement is incorrect.

4. يتفاعل المركب (A) مع المركب (C) ويعطى زيت المروخ.
   (Compound (A) reacts with Compound (C) and gives Oil of Wintergreen.)

   • (A) is Salicylic acid ($C_7H_6O_3$). (C) is Methanol ($CH_4O$).
   • The reaction between Salicylic acid and Methanol in the presence of an acid catalyst is an esterification reaction: $C_6H_4(OH)COOH + CH_3OH \xrightarrow{H^+} C_6H_4(OH)COOCH_3 + H_2O$
   • The product, $C_6H_4(OH)COOCH_3$, is Methyl Salicylate.
   • Methyl Salicylate is commonly known as "Oil of Wintergreen" (زيت المروخ).
   • This statement accurately describes a known chemical reaction and product. Therefore, this statement is correct.

Conclusion:
Based on the analysis, only the fourth statement is correct.

The reaction is:
Salicylic acid + Methanol $\xrightarrow{H^+}$ Methyl Salicylate + Water

Visual representation of the reaction:

Explanation of the solution:

1. Identify the compounds based on their molecular formulas: (A) Salicylic acid ($C_7H_6O_3$), (B) Phenol ($C_6H_6O$), (C) Methanol ($CH_4O$). Compound (D) ($C_3H_6O_2$) is not needed for the final correct option.

2. Evaluate each statement:

   • Statement 1: Phenol + Methanol does not directly form a heat insulator like Bakelite (which requires formaldehyde). Incorrect.
   • Statement 2: Salicylic acid + Methanol forms methyl salicylate, not Dacron (which is from terephthalic acid and ethylene glycol). Incorrect.
   • Statement 3: Acidic hydrolysis of $C_3H_6O_2$ cannot yield $C_6H_6O$ (Phenol) due to differing carbon counts and chemical impossibility. Incorrect.
   • Statement 4: Salicylic acid reacts with Methanol via esterification to form Methyl Salicylate, which is known as Oil of Wintergreen (زيت المروخ). Correct.

Answer:

The correct statement is: يتفاعل المركب (A) مع المركب (C) ويعطى زيت المروخ.