கார்பனைல் சேர்மங்கள் மற்றும் கார்பாக்சிலிக் அமிலங்கள் (12ஆம் வகுப்பு வேதியியல், சமச்சீர் கல்வி) அத்தியாயத்திற்கான, பாடநூலில் இல்லாத 15 கூடுதல் வினாக்கள் — ஒவ்வொன்றிலும் சரியான விடை தனித்துக் காட்டப்பட்டு, தெளிவான படிப்படியான விளக்கத்துடன். தமிழிலும் ஆங்கிலத்திலும் இலவசமாகப் படிக்கலாம்.
Q1
What is the IUPAC name for the compound commonly known as mesityl oxide?
- A. 4-methylpent-3-en-2-oneசரி
- B. 2-methylpent-2-en-4-one
- C. 4-methylpent-2-en-3-one
- D. 3-methylpent-3-en-2-one
விளக்கம். According to IUPAC rules, the numbering of the parent chain begins from the end nearer to the carbonyl group, providing positions for substituents and unsaturation.
Q2
In the structure of a carbonyl group, the carbon atom uses which of the following hybridizations to form its sigma bonds?
- A. sp
- B. \(sp^{2}\)சரி
- C. \(sp^{3}\)
- D. \(dsp^{2}\)
விளக்கம். The carbonyl carbon atom is bonded to three other atoms in a trigonal planar arrangement using three sp2 hybrid orbitals, leaving one p orbital to form the pi bond.
Q3
Which reagent is specifically used to oxidize a primary alcohol to an aldehyde while preventing further oxidation to a carboxylic acid?
- A. Acidified \(K_{2}Cr_{2}O_{7}\)
- B. Alkaline \(KMnO_{4}\)
- C. Pyridinium Chlorochromate (PCC)சரி
- D. Hot concentrated \(HNO_{3}\)
விளக்கம். PCC is a mild oxidizing agent that selectively oxidizes primary alcohols to aldehydes and stops there, unlike stronger agents that continue to carboxylic acids.
Q4
The Gattermann-Koch reaction utilizes carbon monoxide and hydrogen chloride to synthesize which aromatic compound from benzene?
- A. Acetophenone
- B. Benzaldehydeசரி
- C. Benzophenone
- D. Chlorobenzene
விளக்கம். This reaction involves benzene reacting with carbon monoxide and hydrogen chloride in the presence of an aluminum chloride catalyst to introduce a formyl group.
Q5
Aldehydes and ketones generally have higher boiling points than non-polar hydrocarbons of similar molar mass due to:
- A. Intermolecular hydrogen bonding
- B. Strong covalent network bonding
- C. Intermolecular dipole-dipole interactionsசரி
- D. Intramolecular forces
விளக்கம். The polarity of the carbonyl group leads to strong dipole-dipole interactions between molecules, requiring more energy to overcome than the van der Waals forces in non-polar hydrocarbons.
Q6
What organic product is obtained when a cyanohydrin undergoes complete acid hydrolysis?
- A. An \(\alpha\)-hydroxy acidசரி
- B. A primary amine
- C. An aliphatic nitrile
- D. An \(\alpha\)-amino acid
விளக்கம். Under acidic conditions, the nitrile group of a cyanohydrin is converted into a carboxylic acid group, resulting in the formation of an alpha-hydroxy acid.
Q7
According to Popoff's rule, in the vigorous oxidation of an unsymmetrical ketone, with which part does the carbonyl group remain associated?
- A. The larger alkyl group
- B. The smaller alkyl groupசரி
- C. It is always released as \(CO_{2}\)
- D. Both parts equally
விளக்கம். Popoff's rule states that during the vigorous oxidation of unsymmetrical ketones, the keto group stays associated with the smaller alkyl group after bond cleavage.
Q8
In the base-catalyzed aldol condensation mechanism, what is the role of the dilute \(NaOH\)?
- A. To protonate the carbonyl oxygen
- B. To act as a nucleophile attacking the carbon
- C. To abstract an \(\alpha\)-hydrogen to form a carbanionசரி
- D. To dehydrate the intermediate
விளக்கம். The initial step involves a strong base abstracting an acidic alpha-hydrogen atom to generate a nucleophilic carbanion, known as an enolate ion.
Q9
What is the correct IUPAC name for the dicarboxylic acid commonly known as succinic acid?
- A. Ethane-1,2-dioic acid
- B. Propane-1,3-dioic acidசரி
- C. Butanedioic acid
- D. Pentane-1,5-dioic acid
விளக்கம். Succinic acid is a saturated dicarboxylic acid with a four-carbon chain, where the two carboxyl groups are located at the ends of the chain.
Q10
The Rosenmund reduction involves the conversion of acid chlorides to aldehydes using hydrogen and which catalyst system?
- A. \(LiAlH_{4}\) in dry ether
- B. \(H_{2}\) / \(Pd-BaSO_{4}\) poisoned with sulfur
- C. \(Zn-Hg\) and concentrated \(HCl\)சரி
- D. \(SnCl_{2}\) and \(HCl\)
விளக்கம். In this reaction, acid chlorides are partially reduced using hydrogen gas and a palladium catalyst poisoned with sulfur or quinoline to stop at the aldehyde.
Q11
Which of the following chloro-substituted acetic acids is expected to be the most acidic?
- A. Monochloroacetic acid
- B. Dichloroacetic acidசரி
- C. Trichloroacetic acid
- D. Acetic acid
விளக்கம். Trichloroacetic acid is the strongest because the three electron-withdrawing chlorine atoms significantly stabilize the carboxylate anion through the inductive effect.
Q12
The Hell-Volhard-Zelinsky (HVZ) reaction results in halogenation at which position of the carboxylic acid chain?
- A. The carboxyl carbon
- B. The \(\alpha\)-carbonசரி
- C. The terminal methyl group
- D. The \(\beta\)-carbon
விளக்கம். This specific reaction involves the halogenation of a carboxylic acid at the alpha-carbon atom in the presence of red phosphorus and a halogen.
Q13
Dry distillation of calcium acetate yields which of the following products?
- A. Acetaldehydeசரி
- B. Formaldehyde
- C. Acetone
- D. Acetic acid
விளக்கம். The dry distillation of calcium acetate involves heating the solid salt, which decomposes into acetone and calcium carbonate as the inorganic byproduct.
Q14
In the reaction of a carboxylic acid with an alcohol to form an ester, what is the typical catalyst used?
- A. Dilute \(NaOH\)சரி
- B. Concentrated \(H_{2}SO_{4}\)
- C. Anhydrous \(AlCl_{3}\)
- D. Red phosphorus
விளக்கம். Concentrated sulfuric acid acts as both a catalyst and a dehydrating agent, shifting the equilibrium toward the ester by removing the water produced.
Q15
Which carbonyl compound is widely used as a flavoring agent due to its characteristic almond-like odor?
- A. Formaldehyde
- B. Acetone
- C. Benzaldehydeசரி
- D. Butanone
விளக்கம். Due to its pleasant almond-like fragrance, benzaldehyde is extensively used as a synthetic flavoring agent in foods and as a scent in perfumes.
