Q50. Choose the correct answer from the options given below:
(A) Toluene to Benzaldehyde (Etard reac

Q: What is the correct answer for CUET UG Chemistry Q50?

The correct answer is d. Let's examine each reaction scheme:(A) **Toluene to Benzaldehyde (Etard reaction):** This reaction uses chromyl chloride (CrO₂Cl₂) followed by hydrolysis to oxidize a methyl group on an aromatic ring to an aldehyde group. The image shows Toluene --(CrO₂Cl₂, H₃O⁺)--> Benzaldehyde. This is a **correct** representation of the Etard reaction.(B) **RCOCl to RCHO (Rosenmund reduction):** This is the cat

Q: Q50. Choose the correct answer from the options given below: (A) Toluene to Benzaldehyde (Etard reaction) (B) RCOCl to RCHO (Rosenmund reduction) (C) Ketone to Alkane (Clemmensen reduction) (D)…

The correct answer is d. Let's examine each reaction scheme:(A) **Toluene to Benzaldehyde (Etard reaction):** This reaction uses chromyl chloride (CrO₂Cl₂) followed by hydrolysis to oxidize a methyl group on an aromatic ring to an aldehyde group. The image shows Toluene --(CrO₂Cl₂, H₃O⁺)--> Benzaldehyde. This is a **correct** representation of the Etard reaction.(B) **RCOCl to RCHO (Rosenmund reduction):** This is the cat

Q: What are the options for this CUET UG Chemistry question?

A. (A), (B), (C), (D) only · B. (B), (C), (D), (E) only · C. (E), (A), (D) only · D. (A), (B), (C), (E) only

Question

Q50. Choose the correct answer from the options given below:
(A) Toluene to Benzaldehyde (Etard reaction)
(B) RCOCl to RCHO (Rosenmund reduction)
(C) Ketone to Alkane (Clemmensen reduction)
(D) Ketone to Alkane (Wolff-Kishner reduction) (reagents: H₂N-NH₂, H₃O⁺)
(E) Benzene to Benzaldehyde (Gattermann Koch reaction) (reagents: CO, HCl)

FirstInTest · Accepted Answer

Let's examine each reaction scheme:(A) **Toluene to Benzaldehyde (Etard reaction):** This reaction uses chromyl chloride (CrO₂Cl₂) followed by hydrolysis to oxidize a methyl group on an aromatic ring to an aldehyde group. The image shows Toluene --(CrO₂Cl₂, H₃O⁺)--> Benzaldehyde. This is a **correct** representation of the Etard reaction.(B) **RCOCl to RCHO (Rosenmund reduction):** This is the catalytic hydrogenation of an acyl chloride (RCOCl) to an aldehyde (RCHO) using hydrogen gas over a poisoned palladium catalyst (H₂/Pd-BaSO₄, often with sulfur or quinoline). The image shows RCOCl --(H₂/Pd, BaSO₄)--> RCHO. This is a **correct** representation of the Rosenmund reduction.(C) **Ketone to Alkane (Clemmensen reduction):** This reaction reduces a carbonyl group (aldehyde or ketone) to a methylene group (-CH₂) using zinc amalgam (Zn-Hg) and concentrated hydrochloric acid (HCl). The image shows C=O --(Zn(Hg), HCl)--> CH₂. This is a **correct** representation of the Clemmensen reduction.(D) **Ketone to Alkane (Wolff-Kishner reduction):** The Wolff-Kishner reduction uses hydrazine (H₂N-NH₂) and a strong base (like KOH or NaOH) in a high-boiling solvent (like ethylene glycol) at elevated temperatures. The given reagents are H₂N-NH₂ and H₃O⁺. Acidic conditions (H₃O⁺) would hydrolyze the hydrazone intermediate back to the ketone, rather than reducing it to an alkane. Thus, the reagents shown (H₃O⁺ instead of base) make this **incorrect** for Wolff-Kishner reduction to an alkane.(E) **Benzene to Benzaldehyde (Gattermann Koch reaction):** This reaction synthesizes benzaldehyde from benzene (or its derivatives) using carbon monoxide (CO) and hydrogen chloride (HCl) in the presence of anhydrous aluminum chloride (AlCl₃) and sometimes cuprous chloride (CuCl) as a catalyst. The image shows a C=O group being converted to a CHO group using CO, HCl, implying the Gattermann-Koch formylation of an aromatic ring. This is a **correct** representation of the Gattermann-Koch reaction.Therefore, the correct reactions are (A), (B), (C), and (E). This matches option (d).

Answer

(A), (B), (C), (D) only

Answer

(B), (C), (D), (E) only

Answer

(E), (A), (D) only

Answer

(A), (B), (C), (E) only

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