Class 12 Extra questions English Flamingo Chapter 3 Deep Water by William Douglas

Class 12 Extra questions                    English Flamingo Chapter 3                                                                           Deep Water by William Douglas 1. Q: What initial event led to Douglas's fear of water?    A: Douglas's fear of water began when he was thrown into the deep end of the Y.M.C.A. pool by a bully, nearly causing him to drown.   2. Q: How did Douglas’s early experiences at the beach contribute to his fear?    A: As a child, Douglas had been knocked down by waves at a beach in California, which left him frightened of water. 3. Q: Why did Douglas decide to learn swimming despite his fear?    A: Douglas decided to learn swimming to overcome his debilitating fear and regain confidenc...

"Study With Mayank Sir" Chemistry MCQ Chapter 8 Aldehyde Ketone and Carboxylic Acids

"Study with Mayank Sir" - To be ahead in exam room .

Chapter–8 Aldehydes, Ketones and Carboxylic Acids

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Question Type: MCQ (Application-based)
Marks: 0.5 × 50 = 25 marks

Q1. Which compound will give silver mirror test?
कौन-सा यौगिक सिल्वर मिरर टेस्ट देगा?
A. Acetone / एसीटोन
B. Benzaldehyde / बेंज़ाल्डिहाइड
C. Benzophenone / बेंज़ोफिनोन
D. Acetophenone / एसीटोफिनोन
✅ Answer: B – Benzaldehyde / बेंज़ाल्डिहाइड
Explanation: Aldehydes give Tollens’ test; benzaldehyde is an aldehyde.
Q2. Which reagent distinguishes aldehyde from ketone?
एल्डिहाइड और कीटोन में अंतर करने वाला अभिकर्मक कौन-सा है?
A. Fehling solution / फेलिंग विलयन
B. Grignard reagent / ग्रिग्नार्ड अभिकर्मक
C. NaBH₄ / सोडियम बोरोहाइड्राइड
D. PCl₅ / पीसीएल₅
✅ Answer: A – Fehling solution / फेलिंग विलयन
Explanation: Aldehydes reduce Fehling solution; ketones do not.
Q3. Which compound does NOT undergo Cannizzaro reaction?
कौन-सा यौगिक कैनिज़ारो अभिक्रिया नहीं करता?
A. Formaldehyde / फॉर्मेल्डिहाइड
B. Benzaldehyde / बेंज़ाल्डिहाइड
C. Acetaldehyde / एसीटाल्डिहाइड
D. p-Chlorobenzaldehyde / p-क्लोरोबेंज़ाल्डिहाइड
✅ Answer: C – Acetaldehyde / एसीटाल्डिहाइड
Explanation: Cannizzaro reaction occurs in aldehydes without α-hydrogen.
Q4. Which oxidation converts aldehyde into carboxylic acid?
कौन-सा ऑक्सीकरण एल्डिहाइड को कार्बोक्सिलिक अम्ल में बदलता है?
A. PCC
B. Tollens’ reagent
C. Clemmensen reduction
D. Rosenmund reduction
✅ Answer: B – Tollens’ reagent / टोलेंस अभिकर्मक
Explanation: Tollens’ reagent oxidises aldehydes to acids.
Q5. Which acid is strongest?
सबसे प्रबल अम्ल कौन-सा है?
A. Acetic acid / एसिटिक अम्ल
B. Chloroacetic acid / क्लोरोएसिटिक अम्ल
C. Dichloroacetic acid / डाइक्लोरोएसिटिक अम्ल
D. Trichloroacetic acid / ट्राइक्लोरोएसिटिक अम्ल
✅ Answer: D – Trichloroacetic acid / ट्राइक्लोरोएसिटिक अम्ल
Explanation: More –Cl groups increase −I effect, increasing acidity.
Q6. Which compound gives iodoform test?
कौन-सा यौगिक आयोडोफॉर्म टेस्ट देता है?
A. Acetone / एसीटोन
B. Formaldehyde / फॉर्मेल्डिहाइड
C. Benzaldehyde / बेंज़ाल्डिहाइड
D. Formic acid / फॉर्मिक अम्ल
✅ Answer: A – Acetone / एसीटोन
Explanation: Compounds with –COCH₃ group give iodoform test.
Q7. Reduction of carboxylic acid with LiAlH₄ gives:
LiAlH₄ द्वारा कार्बोक्सिलिक अम्ल का अपचयन क्या देता है?
A. Aldehyde / एल्डिहाइड
B. Ketone / कीटोन
C. Primary alcohol / प्राथमिक अल्कोहल
D. Secondary alcohol / द्वितीयक अल्कोहल
✅ Answer: C – Primary alcohol / प्राथमिक अल्कोहल
Explanation: LiAlH₄ reduces acids to primary alcohols.
Q8. Which compound shows keto–enol tautomerism?
कौन-सा यौगिक कीटो–इनॉल टॉटोमरिज़्म दर्शाता है?
A. Benzaldehyde
B. Acetone
C. Formaldehyde
D. Benzophenone
✅ Answer: B – Acetone / एसीटोन
Explanation: Presence of α-hydrogen enables keto–enol tautomerism.
Q9. Which reagent converts acid chloride to aldehyde?
कौन-सा अभिकर्मक अम्ल क्लोराइड को एल्डिहाइड में बदलता है?
A. Zn–Hg/HCl
B. Pd/BaSO₄
C. LiAlH₄
D. NaOH
✅ Answer: B – Pd/BaSO₄
Explanation: Rosenmund reduction converts acid chlorides to aldehydes.
Q10. Which compound gives effervescence with NaHCO₃?
NaHCO₃ के साथ बुलबुले कौन-सा यौगिक देगा?
A. Phenol / फिनॉल
B. Ethanol / एथेनॉल
C. Acetic acid / एसिटिक अम्ल
D. Benzaldehyde / बेंज़ाल्डिहाइड
✅ Answer: C – Acetic acid / एसिटिक अम्ल
Explanation: Carboxylic acids react with NaHCO₃ releasing CO₂.

Q11. Which compound gives positive Fehling test?
कौन-सा यौगिक फेलिंग टेस्ट देता है?
A. Benzaldehyde / बेंज़ाल्डिहाइड
B. Acetaldehyde / एसीटाल्डिहाइड
C. Acetone / एसीटोन
D. Benzophenone / बेंज़ोफिनोन
✅ Answer: B – Acetaldehyde / एसीटाल्डिहाइड
Explanation: Aliphatic aldehydes reduce Fehling solution.
Q12. Formic acid behaves differently because it:
फॉर्मिक अम्ल भिन्न व्यवहार करता है क्योंकि यह—
A. Is aromatic / एरोमैटिक है
B. Acts as reducing agent / अपचायक है
C. Has ketonic group / कीटोनिक समूह है
D. Is unsaturated / असंतृप्त है
✅ Answer: B – Acts as reducing agent / अपचायक है
Explanation: Formic acid is easily oxidised to CO₂.
Q13. Which reagent converts aldehyde to primary alcohol?
कौन-सा अभिकर्मक एल्डिहाइड को प्राथमिक अल्कोहल में बदलता है?
A. PCC
B. NaBH₄
C. KMnO₄
D. Tollens’ reagent
✅ Answer: B – NaBH₄
Explanation: NaBH₄ reduces aldehydes to primary alcohols.
Q14. Which compound undergoes aldol condensation?
कौन-सा यौगिक एल्डोल संघनन करता है?
A. Formaldehyde
B. Benzaldehyde
C. Acetaldehyde
D. Benzophenone
✅ Answer: C – Acetaldehyde / एसीटाल्डिहाइड
Explanation: Aldol condensation requires α-hydrogen.
Q15. Which acid is weakest?
सबसे कमजोर अम्ल कौन-सा है?
A. Formic acid
B. Acetic acid
C. Propionic acid
D. Trichloroacetic acid
✅ Answer: C – Propionic acid / प्रोपियोनिक अम्ल
Explanation: +I effect of alkyl group decreases acidity.
Q16. Which reaction is used to prepare aldehyde from nitrile?
नाइट्राइल से एल्डिहाइड बनाने की अभिक्रिया कौन-सी है?
A. Clemmensen reduction
B. Stephen reaction
C. Cannizzaro reaction
D. Aldol reaction
✅ Answer: B – Stephen reaction
Explanation: Stephen reduction converts nitriles to aldehydes.
Q17. Which compound gives fruity smell?
फल जैसी गंध देने वाला यौगिक कौन-सा है?
A. Ketone
B. Ester
C. Aldehyde
D. Acid chloride
✅ Answer: B – Ester / एस्टर
Explanation: Esters generally have fruity odour.
Q18. Which reagent oxidises alcohol to aldehyde only?
कौन-सा अभिकर्मक अल्कोहल को केवल एल्डिहाइड में ऑक्सीकरण करता है?
A. KMnO₄
B. K₂Cr₂O₇
C. PCC
D. Tollens’ reagent
✅ Answer: C – PCC
Explanation: PCC oxidises primary alcohol to aldehyde without over-oxidation.
Q19. Which compound does NOT show nucleophilic addition?
कौन-सा यौगिक न्यूक्लियोफिलिक योग नहीं करता?
A. Aldehyde
B. Ketone
C. Carboxylic acid
D. Formaldehyde
✅ Answer: C – Carboxylic acid
Explanation: –OH group reduces electrophilicity of carbonyl carbon.
Q20. Which compound gives white precipitate with Tollens’ reagent?
टोलेंस अभिकर्मक के साथ सफेद अवक्षेप कौन-सा देता है?
A. Benzaldehyde
B. Acetone
C. Acetic acid
D. Benzophenone
✅ Answer: A – Benzaldehyde
Explanation: Aldehydes give silver mirror/precipitate.
Q21. Which reaction converts ketone to alkane?
कौन-सी अभिक्रिया कीटोन को एल्केन में बदलती है?
A. Rosenmund
B. Clemmensen
C. Aldol
D. Cannizzaro
✅ Answer: B – Clemmensen
Explanation: Clemmensen reduction converts carbonyl to –CH₂–.
Q22. Which acid is present in vinegar?
सिरके में कौन-सा अम्ल होता है?
A. Formic acid
B. Oxalic acid
C. Acetic acid
D. Benzoic acid
✅ Answer: C – Acetic acid / एसिटिक अम्ल
Explanation: Vinegar contains dilute acetic acid.
Q23. Which compound shows optical isomerism?
कौन-सा यौगिक प्रकाशीय समावयवता दर्शाता है?
A. Acetone
B. Lactic acid
C. Formaldehyde
D. Acetic acid
✅ Answer: B – Lactic acid
Explanation: Lactic acid has chiral carbon.
Q24. Which acid is used in food preservation?
खाद्य संरक्षण में कौन-सा अम्ल प्रयुक्त होता है?
A. Oxalic acid
B. Benzoic acid
C. Formic acid
D. Citric acid
✅ Answer: B – Benzoic acid
Explanation: Benzoic acid inhibits microbial growth.
Q25. Which compound gives yellow precipitate with I₂/NaOH?
I₂/NaOH के साथ पीला अवक्षेप कौन-सा देता है?
A. Ethanol
B. Acetone
C. Acetic acid
D. Benzaldehyde
✅ Answer: B – Acetone
Explanation: Iodoform test gives yellow CHI₃ precipitate.
Q26. Which compound shows maximum +I effect?
सबसे अधिक +I प्रभाव कौन-सा दिखाता है?
A. CH₃COOH
B. ClCH₂COOH
C. CCl₃COOH
D. HCOOH
✅ Answer: A – CH₃COOH
Explanation: Alkyl groups show +I effect.
Q27. Which acid is dibasic?
कौन-सा अम्ल द्विक्षारकीय है?
A. Acetic acid
B. Formic acid
C. Oxalic acid
D. Benzoic acid
✅ Answer: C – Oxalic acid
Explanation: Oxalic acid has two –COOH groups.
Q28. Which compound undergoes nucleophilic substitution instead of addition?
न्यूक्लियोफिलिक योग की बजाय प्रतिस्थापन कौन करता है?
A. Aldehyde
B. Ketone
C. Acid chloride
D. Acetone
✅ Answer: C – Acid chloride
Explanation: Acid chlorides undergo nucleophilic substitution.
Q29. Which compound reduces Tollens’ reagent fastest?
टोलेंस अभिकर्मक को सबसे तेजी से कौन घटाता है?
A. Benzaldehyde
B. Acetaldehyde
C. Formaldehyde
D. Acetic acid
✅ Answer: C – Formaldehyde
Explanation: Formaldehyde is most easily oxidised.
Q30. Which acid is solid at room temperature?
कक्ष ताप पर ठोस कौन-सा अम्ल है?
A. Acetic acid
B. Formic acid
C. Benzoic acid
D. Lactic acid
✅ Answer: C – Benzoic acid
Explanation: Aromatic acids have higher melting points.
Q31. Which compound gives haloform reaction?
हैलोफॉर्म अभिक्रिया कौन करता है?
A. Ethanol
B. Acetaldehyde
C. Acetone
D. Benzaldehyde
✅ Answer: C – Acetone
Explanation: Presence of –COCH₃ group is required.
Q32. Which reaction forms β-hydroxy aldehyde?
β-हाइड्रॉक्सी एल्डिहाइड कौन-सी अभिक्रिया से बनता है?
A. Cannizzaro
B. Aldol
C. Clemmensen
D. Rosenmund
✅ Answer: B – Aldol
Explanation: Aldol reaction forms β-hydroxy aldehyde.
Q33. Which acid shows strongest hydrogen bonding?
सबसे प्रबल हाइड्रोजन बंधन कौन-सा अम्ल दिखाता है?
A. Formic acid
B. Acetic acid
C. Oxalic acid
D. Benzoic acid
✅ Answer: C – Oxalic acid
Explanation: Multiple –COOH groups enhance H-bonding.
Q34. Which compound has lowest boiling point?
सबसे कम क्वथनांक किसका है?
A. Acetone
B. Ethanol
C. Acetic acid
D. Propanol
✅ Answer: A – Acetone
Explanation: No hydrogen bonding in ketones.
Q35. Which acid is present in ant sting?
चींटी के डंक में कौन-सा अम्ल होता है?
A. Acetic acid
B. Formic acid
C. Lactic acid
D. Oxalic acid
✅ Answer: B – Formic acid
Explanation: Ant sting contains formic acid.
Q36. Which compound does NOT give nucleophilic addition?
न्यूक्लियोफिलिक योग नहीं देने वाला यौगिक कौन-सा है?
A. Formaldehyde
B. Acetone
C. Benzaldehyde
D. Acetic acid
✅ Answer: D – Acetic acid
Explanation: Carboxylic acids resist addition reactions.
Q37. Which reagent oxidises aldehyde to acid but not ketone?
एल्डिहाइड को अम्ल में ऑक्सीकरण करता है लेकिन कीटोन को नहीं?
A. Tollens’ reagent
B. NaBH₄
C. PCC
D. LiAlH₄
✅ Answer: A – Tollens’ reagent
Explanation: Aldehydes are easily oxidised; ketones are resistant.
Q38. Which compound shows pleasant smell?
सुखद गंध कौन देता है?
A. Acid
B. Aldehyde
C. Ketone
D. Ester
✅ Answer: D – Ester
Explanation: Esters have fruity smell.
Q39. Which compound forms gem-diol in aqueous solution?
जलीय विलयन में जेम-डायोल कौन बनाता है?
A. Formaldehyde
B. Acetone
C. Benzaldehyde
D. Acetic acid
✅ Answer: A – Formaldehyde
Explanation: Small aldehydes readily hydrate.
Q40. Which acid forms cyclic dimers?
चक्रीय डाइमर कौन-सा अम्ल बनाता है?
A. Acetic acid
B. Benzoic acid
C. Formic acid
D. Oxalic acid
✅ Answer: B – Benzoic acid
Explanation: Carboxylic acids dimerise via H-bonding.
Q41. Which compound is least reactive towards nucleophilic addition?
न्यूक्लियोफिलिक योग के प्रति सबसे कम क्रियाशील कौन है?
A. Formaldehyde
B. Acetaldehyde
C. Acetone
D. Benzaldehyde
✅ Answer: D – Benzaldehyde
Explanation: Aromatic ring decreases electrophilicity.
Q42. Which reaction produces carboxylic acid directly?
सीधे कार्बोक्सिलिक अम्ल कौन-सी अभिक्रिया से बनता है?
A. Oxidation of aldehyde
B. Reduction of ketone
C. Aldol reaction
D. Cannizzaro
✅ Answer: A – Oxidation of aldehyde
Explanation: Aldehydes oxidise to acids.
Q43. Which compound has highest boiling point?
सबसे अधिक क्वथनांक किसका है?
A. Acetone
B. Ethanol
C. Acetic acid
D. Propanal
✅ Answer: C – Acetic acid
Explanation: Strong intermolecular hydrogen bonding.
Q44. Which compound gives Schiff’s test?
शिफ़ टेस्ट कौन देता है?
A. Ketone
B. Aldehyde
C. Carboxylic acid
D. Ester
✅ Answer: B – Aldehyde
Explanation: Schiff’s reagent reacts with aldehydes.
Q45. Which compound is reducing agent?
अपचायक कौन-सा है?
A. Acetic acid
B. Formic acid
C. Benzoic acid
D. Oxalic acid
✅ Answer: B – Formic acid
Explanation: Easily oxidised to CO₂.
Q46. Which reaction increases carbon chain length?
कार्बन श्रृंखला बढ़ाने वाली अभिक्रिया कौन-सी है?
A. Cannizzaro
B. Aldol
C. Clemmensen
D. Rosenmund
✅ Answer: B – Aldol
Explanation: Aldol reaction combines two molecules.
Q47. Which compound gives white ppt with NaHCO₃?
NaHCO₃ के साथ सफेद अवक्षेप कौन देता है?
A. Acetone
B. Ethanol
C. Acetic acid
D. Benzaldehyde
✅ Answer: C – Acetic acid
Explanation: CO₂ evolution confirms carboxylic acid.
Q48. Which compound is most acidic?
सबसे अधिक अम्लीय कौन-सा है?
A. CH₃COOH
B. ClCH₂COOH
C. CCl₃COOH
D. HCOOH
✅ Answer: C – CCl₃COOH
Explanation: Strong −I effect increases acidity.
Q49. Which compound gives esterification?
एस्टरीकरण कौन-सा यौगिक करता है?
A. Ketone
B. Aldehyde
C. Carboxylic acid
D. Alkene
✅ Answer: C – Carboxylic acid
Explanation: Acids react with alcohols to form esters.
Q50. Which compound does NOT show Cannizzaro reaction?
कैनिज़ारो अभिक्रिया कौन नहीं करता?
A. Formaldehyde
B. Benzaldehyde
C. Acetaldehyde
D. p-Nitrobenzaldehyde
✅ Answer: C – Acetaldehyde
Explanation: Presence of α-hydrogen prevents Cannizzaro reaction.


  • Question Type: MCQ (Skill based)
  • Marks: 0.5 × 50 = 25 Marks


Q1. Which reagent distinguishes aldehydes from ketones?
कौन-सा अभिकर्मक एल्डिहाइड और कीटोन में भेद करता है?
A. Fehling’s solution / फेलिंग विलयन
B. Benedict’s solution / बेनेडिक्ट विलयन
C. Tollens’ reagent / टोलेंस अभिकर्मक
D. All of these / उपरोक्त सभी
✔ Answer: C / Tollens’ reagent (टोलेंस अभिकर्मक)
Explanation: Aldehydes reduce Tollens’ reagent forming silver mirror; ketones do not.
Q2. Which compound gives positive Fehling test?
कौन-सा यौगिक फेलिंग परीक्षण देता है?
A. Benzaldehyde / बेंज़ाल्डिहाइड
B. Acetone / एसीटोन
C. Formaldehyde / फॉर्मल्डिहाइड
D. Benzophenone / बेंज़ोफिनोन
✔ Answer: C / Formaldehyde (फॉर्मल्डिहाइड)
Explanation: Aliphatic aldehydes give Fehling test; formaldehyde is aliphatic.
Q3. Cannizzaro reaction is shown by:
कैनिज़ारो अभिक्रिया किसमें होती है?
A. Aldehydes with α-H / α-H युक्त एल्डिहाइड
B. Ketones with α-H / α-H युक्त कीटोन
C. Aldehydes without α-H / α-H रहित एल्डिहाइड
D. All aldehydes / सभी एल्डिहाइड
✔ Answer: C / Aldehydes without α-H
Explanation: Cannizzaro reaction occurs in aldehydes lacking alpha hydrogen.
Q4. Which is the strongest acid?
सबसे प्रबल अम्ल कौन-सा है?
A. HCOOH / फॉर्मिक अम्ल
B. CH₃COOH / एसीटिक अम्ल
C. C₂H₅COOH / प्रोपियोनिक अम्ल
D. C₆H₅COOH / बेंज़ोइक अम्ल
✔ Answer: A / Formic acid (फॉर्मिक अम्ल)
Explanation: Electron-donating alkyl groups reduce acidity; formic acid has none.
Q5. Aldol condensation occurs in compounds having:
एल्डोल संघनन किसमें होता है?
A. –CHO only
B. –COOH only
C. α-Hydrogen / α-हाइड्रोजन
D. Aromatic ring / एरोमैटिक रिंग
✔ Answer: C / α-Hydrogen
Explanation: Aldol condensation requires presence of α-hydrogen.
Q6. Which reagent converts aldehyde into alcohol?
कौन-सा अभिकर्मक एल्डिहाइड को अल्कोहल में बदलता है?
A. KMnO₄
B. NaBH₄
C. Tollen’s reagent
D. Fehling solution
✔ Answer: B / NaBH₄
Explanation: NaBH₄ is a mild reducing agent converting aldehydes to alcohols.
Q7. Which acid is used in food preservation?
खाद्य संरक्षण में कौन-सा अम्ल प्रयोग होता है?
A. Oxalic acid / ऑक्सैलिक अम्ल
B. Benzoic acid / बेंज़ोइक अम्ल
C. Formic acid / फॉर्मिक अम्ल
D. Acetic acid / एसीटिक अम्ल
✔ Answer: B / Benzoic acid (बेंज़ोइक अम्ल)
Explanation: Benzoic acid inhibits microbial growth and is used as preservative.
Q8. Which compound does NOT give iodoform test?
कौन-सा यौगिक आयोडोफॉर्म परीक्षण नहीं देता?
A. Acetaldehyde / एसीटैल्डिहाइड
B. Acetone / एसीटोन
C. Ethanol / एथेनॉल
D. Benzaldehyde / बेंज़ाल्डिहाइड
✔ Answer: D / Benzaldehyde
Explanation: Iodoform test requires CH₃CO– or CH₃CH(OH)– group.
Q9. Which is a reducing sugar?
कौन-सा अपचायक शर्करा है?
A. Sucrose / सुक्रोज
B. Glucose / ग्लूकोज़
C. Starch / स्टार्च
D. Cellulose / सेल्यूलोज
✔ Answer: B / Glucose (ग्लूकोज़)
Explanation: Glucose contains free aldehyde group in open chain form.
Q10. Carboxylic acids show acidic nature due to:
कार्बोक्सिलिक अम्ल अम्लीय क्यों होते हैं?
A. –OH group
B. –COOH group
C. Resonance stabilisation / अनुनाद स्थिरीकरण
D. Hydrogen bonding
✔ Answer: C / Resonance stabilisation
Explanation: Carboxylate ion is stabilised by resonance, increasing acidity.

Q11. Which aldehyde does not give Schiff’s test?
कौन-सा एल्डिहाइड शिफ़ परीक्षण नहीं देता?
A. Formaldehyde / फॉर्मल्डिहाइड
B. Acetaldehyde / एसीटैल्डिहाइड
C. Benzaldehyde / बेंज़ाल्डिहाइड
D. All aldehydes / सभी एल्डिहाइड
✔ Answer: C / Benzaldehyde (बेंज़ाल्डिहाइड)
Explanation: Aromatic aldehydes give very slow or negative Schiff’s test.
Q12. Oxidation of aldehydes generally gives:
एल्डिहाइड के ऑक्सीकरण से सामान्यतः क्या बनता है?
A. Alcohol / अल्कोहल
B. Ketone / कीटोन
C. Carboxylic acid / कार्बोक्सिलिक अम्ल
D. Ester / एस्टर
✔ Answer: C / Carboxylic acid (कार्बोक्सिलिक अम्ल)
Explanation: Aldehydes are easily oxidised to corresponding carboxylic acids.
Q13. Which compound shows keto–enol tautomerism?
कौन-सा यौगिक कीटो-इनोल टॉटोमेरिज़्म दर्शाता है?
A. Methanal / मेथनाल
B. Acetone / एसीटोन
C. Benzaldehyde / बेंज़ाल्डिहाइड
D. Formic acid / फॉर्मिक अम्ल
✔ Answer: B / Acetone (एसीटोन)
Explanation: Keto–enol tautomerism requires α-hydrogen.
Q14. Which reagent oxidises aldehyde but not ketone?
कौन-सा अभिकर्मक एल्डिहाइड को ऑक्सीकृत करता है पर कीटोन को नहीं?
A. KMnO₄
B. Tollens’ reagent
C. NaBH₄
D. H₂/Pd
✔ Answer: B / Tollens’ reagent
Explanation: Tollens’ reagent selectively oxidises aldehydes.
Q15. Which acid is present in vinegar?
सिरके में कौन-सा अम्ल पाया जाता है?
A. Formic acid / फॉर्मिक अम्ल
B. Oxalic acid / ऑक्सैलिक अम्ल
C. Acetic acid / एसीटिक अम्ल
D. Citric acid / साइट्रिक अम्ल
✔ Answer: C / Acetic acid (एसीटिक अम्ल)
Explanation: Vinegar contains dilute acetic acid.
Q16. Which compound gives positive iodoform test?
कौन-सा यौगिक आयोडोफॉर्म परीक्षण देता है?
A. Methanol / मेथनॉल
B. Ethanol / एथेनॉल
C. Benzyl alcohol / बेंज़िल अल्कोहल
D. Phenol / फिनॉल
✔ Answer: B / Ethanol (एथेनॉल)
Explanation: Ethanol forms acetaldehyde which gives iodoform test.
Q17. Rosenmund reduction is used to prepare:
रोसेनमंड अवकरण का उपयोग किसके निर्माण में होता है?
A. Alcohol from acid
B. Aldehyde from acyl chloride
C. Ketone from acid
D. Ester from aldehyde
✔ Answer: B / Aldehyde from acyl chloride
Explanation: Rosenmund reduction converts acyl chloride to aldehyde.
Q18. Which acid shows strongest intermolecular H-bonding?
कौन-सा अम्ल सर्वाधिक अंतराअणुक हाइड्रोजन बॉन्डिंग दर्शाता है?
A. Formic acid
B. Acetic acid
C. Benzoic acid
D. Oxalic acid
✔ Answer: D / Oxalic acid
Explanation: Presence of two –COOH groups increases hydrogen bonding.
Q19. Carboxylic acids exist as dimers due to:
कार्बोक्सिलिक अम्ल डाइमर के रूप में क्यों पाए जाते हैं?
A. Ionic bonding
B. Covalent bonding
C. Hydrogen bonding
D. Dipole interaction
✔ Answer: C / Hydrogen bonding
Explanation: Strong intermolecular hydrogen bonding causes dimerisation.
Q20. Which compound gives silver mirror test?
कौन-सा यौगिक सिल्वर मिरर परीक्षण देता है?
A. Acetone
B. Benzophenone
C. Acetaldehyde
D. Acetic acid
✔ Answer: C / Acetaldehyde
Explanation: Aldehydes reduce Tollens’ reagent.
Q21. Which acid is used for removing rust?
जंग हटाने के लिए कौन-सा अम्ल उपयोग होता है?
A. Acetic acid
B. Oxalic acid
C. Citric acid
D. Formic acid
✔ Answer: B / Oxalic acid
Explanation: Oxalic acid dissolves iron oxide.
Q22. Which ketone gives iodoform test?
कौन-सा कीटोन आयोडोफॉर्म परीक्षण देता है?
A. Propanone
B. Butanone
C. Pentanone
D. Cyclohexanone
✔ Answer: A / Propanone (Acetone)
Explanation: Methyl ketones give iodoform test.
Q23. Which compound is least acidic?
कौन-सा यौगिक सबसे कम अम्लीय है?
A. Formic acid
B. Acetic acid
C. Benzoic acid
D. Phenol
✔ Answer: D / Phenol
Explanation: Phenol is weaker acid compared to carboxylic acids.
Q24. Decarboxylation of sodium salt gives:
सोडियम लवण का डी-कार्बोक्सीलेशन क्या देता है?
A. Alkene
B. Alkane
C. Alcohol
D. Aldehyde
✔ Answer: B / Alkane
Explanation: Decarboxylation produces alkane with one carbon less.
Q25. Which reagent converts acid to acyl chloride?
कौन-सा अभिकर्मक अम्ल को एसिल क्लोराइड में बदलता है?
A. SOCl₂
B. NaOH
C. NH₃
D. H₂
✔ Answer: A / SOCl₂
Explanation: Thionyl chloride converts acids into acyl chlorides.
Q26. Which compound does NOT show aldol condensation?
कौन-सा यौगिक एल्डोल संघनन नहीं दर्शाता?
A. Acetaldehyde
B. Benzaldehyde
C. Acetone
D. Propanal
✔ Answer: B / Benzaldehyde
Explanation: Benzaldehyde lacks α-hydrogen.
Q27. Which acid is aromatic?
कौन-सा अम्ल एरोमैटिक है?
A. Acetic acid
B. Benzoic acid
C. Formic acid
D. Oxalic acid
✔ Answer: B / Benzoic acid
Explanation: Benzoic acid contains benzene ring.
Q28. Which reaction gives ester?
कौन-सी अभिक्रिया से एस्टर बनता है?
A. Aldol
B. Cannizzaro
C. Esterification
D. Decarboxylation
✔ Answer: C / Esterification
Explanation: Acid + alcohol → ester.
Q29. Which compound gives fruity smell?
कौन-सा यौगिक फल जैसी गंध देता है?
A. Aldehyde
B. Ketone
C. Ester
D. Acid
✔ Answer: C / Ester
Explanation: Esters are responsible for fruity odours.
Q30. Which acid is present in ant sting?
चींटी के डंक में कौन-सा अम्ल होता है?
A. Acetic acid
B. Formic acid
C. Citric acid
D. Lactic acid
✔ Answer: B / Formic acid
Explanation: Ant sting contains formic acid.
Q31. Which reagent reduces carboxylic acid to alcohol?
कौन-सा अभिकर्मक कार्बोक्सिलिक अम्ल को अल्कोहल में बदलता है?
A. NaBH₄
B. LiAlH₄
C. KMnO₄
D. Tollens
✔ Answer: B / LiAlH₄
Explanation: LiAlH₄ is a strong reducing agent.
Q32. Which compound is aldehyde?
कौन-सा यौगिक एल्डिहाइड है?
A. CH₃COCH₃
B. CH₃CHO
C. CH₃COOH
D. C₆H₅OH
✔ Answer: B / CH₃CHO
Explanation: Presence of –CHO group indicates aldehyde.
Q33. Which test confirms –COOH group?
–COOH समूह की पुष्टि कौन-सा परीक्षण करता है?
A. Fehling
B. Litmus
C. NaHCO₃ test
D. Iodoform
✔ Answer: C / NaHCO₃ test
Explanation: CO₂ effervescence confirms carboxylic acid.
Q34. Which compound is ketone?
कौन-सा यौगिक कीटोन है?
A. Methanal
B. Ethanal
C. Propanone
D. Formic acid
✔ Answer: C / Propanone
Explanation: Ketones contain >C=O group between two carbons.
Q35. Which acid is dibasic?
कौन-सा अम्ल द्विक्षारीय है?
A. Formic acid
B. Acetic acid
C. Oxalic acid
D. Benzoic acid
✔ Answer: C / Oxalic acid
Explanation: Oxalic acid has two –COOH groups.
Q36. Which compound shows Cannizzaro reaction?
कौन-सा यौगिक कैनिज़ारो अभिक्रिया करता है?
A. Acetaldehyde
B. Formaldehyde
C. Propanal
D. Acetone
✔ Answer: B / Formaldehyde
Explanation: Formaldehyde lacks α-hydrogen.
Q37. Which functional group is present in ketone?
कीटोन में कौन-सा क्रियात्मक समूह होता है?
A. –CHO
B. –COOH
C. >C=O
D. –OH
✔ Answer: C / >C=O
Explanation: Ketones contain carbonyl group between two carbons.
Q38. Which compound is used in nail polish remover?
नेल पॉलिश रिमूवर में कौन-सा यौगिक होता है?
A. Ethanol
B. Acetone
C. Benzene
D. Methanol
✔ Answer: B / Acetone
Explanation: Acetone is an effective organic solvent.
Q39. Which acid forms anhydride easily?
कौन-सा अम्ल आसानी से एनहाइड्राइड बनाता है?
A. Formic
B. Acetic
C. Benzoic
D. Oxalic
✔ Answer: B / Acetic acid
Explanation: Acetic acid readily forms acetic anhydride.
Q40. Which compound gives pleasant smell?
कौन-सा यौगिक सुखद गंध देता है?
A. Acid
B. Aldehyde
C. Ketone
D. Ester
✔ Answer: D / Ester
Explanation: Esters have pleasant fruity smell.
Q41. Which aldehyde is aromatic?
कौन-सा एल्डिहाइड एरोमैटिक है?
A. Methanal
B. Ethanal
C. Benzaldehyde
D. Propanal
✔ Answer: C / Benzaldehyde
Explanation: Benzaldehyde contains benzene ring.
Q42. Which compound reacts with NaHCO₃?
कौन-सा यौगिक NaHCO₃ से अभिक्रिया करता है?
A. Alcohol
B. Aldehyde
C. Ketone
D. Carboxylic acid
✔ Answer: D / Carboxylic acid
Explanation: Carboxylic acids release CO₂ with NaHCO₃.
Q43. Which is simplest aldehyde?
सबसे सरल एल्डिहाइड कौन-सा है?
A. Methanal
B. Ethanal
C. Propanal
D. Benzaldehyde
✔ Answer: A / Methanal
Explanation: Methanal has only one carbon atom.
Q44. Which compound is weakest acid?
कौन-सा यौगिक सबसे कमजोर अम्ल है?
A. Formic acid
B. Acetic acid
C. Benzoic acid
D. Ethanol
✔ Answer: D / Ethanol
Explanation: Alcohols are much weaker acids.
Q45. Which test is used for methyl ketone?
मिथाइल कीटोन के लिए कौन-सा परीक्षण होता है?
A. Fehling
B. Tollens
C. Iodoform
D. Schiff
✔ Answer: C / Iodoform test
Explanation: Methyl ketones give yellow iodoform precipitate.
Q46. Which acid is used in soft drinks?
सॉफ्ट ड्रिंक्स में कौन-सा अम्ल होता है?
A. Citric acid
B. Oxalic acid
C. Formic acid
D. Benzoic acid
✔ Answer: A / Citric acid
Explanation: Citric acid gives sour taste.
Q47. Which compound undergoes nucleophilic addition?
कौन-सा यौगिक न्यूक्लियोफिलिक योग अभिक्रिया करता है?
A. Alkane
B. Alkene
C. Aldehyde
D. Ether
✔ Answer: C / Aldehyde
Explanation: Polar C=O group favours nucleophilic addition.
Q48. Which group increases acidity of carboxylic acid?
कौन-सा समूह अम्लीयता बढ़ाता है?
A. –CH₃
B. –C₂H₅
C. –NO₂
D. –NH₂
✔ Answer: C / –NO₂
Explanation: Electron-withdrawing groups increase acidity.
Q49. Which compound is aldehyde functional group?
एल्डिहाइड का क्रियात्मक समूह कौन-सा है?
A. –CO–
B. –COOH
C. –CHO
D. –OH
✔ Answer: C / –CHO
Explanation: –CHO group defines aldehydes.
Q50. Which acid gives effervescence with Na₂CO₃?
कौन-सा अम्ल Na₂CO₃ के साथ उफान देता है?
A. Phenol
B. Alcohol
C. Carboxylic acid
D. Aldehyde
✔ Answer: C / Carboxylic acid
Explanation: CO₂ gas is released due to acid–carbonate reaction.


  • Marks: 0.5 × 50 = 25 marks
  • Question Type: Knowledge-based

Q1. Which functional group is present in aldehydes?
एल्डिहाइड में कौन-सा क्रियात्मक समूह पाया जाता है?
A. –COOH / कार्बोक्सिल समूह
B. –CHO / एल्डिहाइड समूह
C. –CO– / कीटोन समूह
D. –OH / हाइड्रॉक्सिल समूह
✔ Answer:
B. –CHO / एल्डिहाइड समूह
Explanation (English):
Aldehydes contain the –CHO (formyl) functional group at the end of the carbon chain.
Q2. The IUPAC name of CH₃CHO is:
CH₃CHO का IUPAC नाम है:
A. Methanal / मेथनाल
B. Ethanal / एथनाल
C. Propanal / प्रोपनाल
D. Acetone / एसीटोन
✔ Answer:
B. Ethanal / एथनाल
Explanation:
CH₃CHO has two carbon atoms with an aldehyde group → Ethanal.
Q3. Which compound gives Tollens’ test?
कौन-सा यौगिक टॉलेंस परीक्षण देता है?
A. Acetone / एसीटोन
B. Benzophenone / बेंजोफिनोन
C. Formaldehyde / फॉर्मल्डिहाइड
D. Acetic acid / एसीटिक अम्ल
✔ Answer:
C. Formaldehyde / फॉर्मल्डिहाइड
Explanation:
Tollens’ test is given by aldehydes due to oxidation of –CHO group.
Q4. Which of the following is a ketone?
निम्न में से कौन-सा कीटोन है?
A. CH₃CHO
B. HCHO
C. CH₃COCH₃
D. HCOOH
✔ Answer:
C. CH₃COCH₃
Explanation:
Ketones have carbonyl group (>C=O) bonded to two carbon atoms.
Q5. The functional group present in carboxylic acids is:
कार्बोक्सिलिक अम्लों में पाया जाने वाला क्रियात्मक समूह है:
A. –CHO
B. –CO–
C. –COOH
D. –OH
✔ Answer:
C. –COOH
Explanation:
Carboxylic acids contain the carboxyl group (–COOH).
Q6. Which of the following is the strongest acid?
निम्न में से सबसे प्रबल अम्ल कौन-सा है?
A. Phenol / फिनॉल
B. Ethanol / एथेनॉल
C. Acetic acid / एसीटिक अम्ल
D. Water / जल
✔ Answer:
C. Acetic acid / एसीटिक अम्ल
Explanation:
Carboxylic acids are stronger acids due to resonance stabilisation of carboxylate ion.
Q7. Which reagent distinguishes aldehydes from ketones?
कौन-सा अभिकर्मक एल्डिहाइड व कीटोन में अंतर करता है?
A. Fehling’s solution / फेलिंग विलयन
B. NaOH
C. H₂SO₄
D. NH₃
✔ Answer:
A. Fehling’s solution / फेलिंग विलयन
Explanation:
Aldehydes reduce Fehling’s solution, ketones do not.
Q8. Which compound gives iodoform test?
आयोडोफॉर्म परीक्षण कौन-सा यौगिक देता है?
A. Methanal
B. Ethanal
C. Benzaldehyde
D. Formic acid
✔ Answer:
B. Ethanal / एथनाल
Explanation:
Ethanal contains CH₃–CO– group after oxidation and gives iodoform test.
Q9. The general formula of aldehydes is:
एल्डिहाइड का सामान्य सूत्र है:
A. CₙH₂ₙO
B. CₙH₂ₙ₊₂O
C. CₙH₂ₙO₂
D. CₙH₂ₙ₋₂O
✔ Answer:
A. CₙH₂ₙO
Explanation:
Open-chain aldehydes follow the formula CₙH₂ₙO.
Q10. Which acid is present in vinegar?
सिरके में कौन-सा अम्ल पाया जाता है?
A. Formic acid
B. Oxalic acid
C. Acetic acid
D. Citric acid
✔ Answer:
C. Acetic acid / एसीटिक अम्ल

Q11. Which aldehyde does NOT give Fehling’s test?
कौन-सा एल्डिहाइड फेलिंग परीक्षण नहीं देता है?
A. Acetaldehyde / एसीटैल्डिहाइड
B. Formaldehyde / फॉर्मल्डिहाइड
C. Benzaldehyde / बेंज़ाल्डिहाइड
D. Propanal / प्रोपनाल
✔ Answer:
C. Benzaldehyde / बेंज़ाल्डिहाइड
Explanation:
Aromatic aldehydes do not reduce Fehling’s solution.
Q12. The IUPAC name of acetone is:
एसीटोन का IUPAC नाम है:
A. Propan-1-one
B. Propan-2-one
C. Ethanal
D. Methanone
✔ Answer:
B. Propan-2-one
Explanation:
Carbonyl group is on second carbon → Propan-2-one.
Q13. Which acid is the strongest among the following?
निम्न में से सबसे प्रबल अम्ल कौन-सा है?
A. CH₃COOH
B. C₂H₅COOH
C. HCOOH
D. C₆H₅COOH
✔ Answer:
C. HCOOH / Formic acid
Explanation:
Formic acid has no electron-donating alkyl group, hence strongest.
Q14. Which compound gives silver mirror test?
कौन-सा यौगिक सिल्वर मिरर परीक्षण देता है?
A. Acetone
B. Ethanol
C. Benzaldehyde
D. Acetic acid
✔ Answer:
C. Benzaldehyde / बेंज़ाल्डिहाइड
Explanation:
Aldehydes give Tollens’ test (silver mirror).
Q15. Which functional group is present in ketones?
कीटोन में कौन-सा क्रियात्मक समूह होता है?
A. –CHO
B. –CO–
C. –COOH
D. –OH
✔ Answer:
B. –CO–
Explanation:
Ketones contain a carbonyl group bonded to two carbon atoms.
Q16. Which compound shows both acidic and reducing nature?
कौन-सा यौगिक अम्लीय व अपचायक दोनों होता है?
A. Acetic acid
B. Formic acid
C. Oxalic acid
D. Benzoic acid
✔ Answer:
B. Formic acid / फॉर्मिक अम्ल
Explanation:
Formic acid reduces Tollens’ reagent and is acidic.
Q17. Which reagent oxidises aldehydes to acids?
कौन-सा अभिकर्मक एल्डिहाइड को अम्ल में ऑक्सीकरण करता है?
A. NaOH
B. Fehling’s solution
C. Tollen’s reagent
D. Both B and C
✔ Answer:
D. Both B and C / दोनों
Explanation:
Both Fehling’s and Tollens’ reagents oxidise aldehydes.
Q18. Which compound does NOT give iodoform test?
कौन-सा यौगिक आयोडोफॉर्म परीक्षण नहीं देता है?
A. Ethanal
B. Acetone
C. Ethanol
D. Methanol
✔ Answer:
D. Methanol / मेथनॉल
Explanation:
Iodoform test requires CH₃–CO– or CH₃–CH(OH)– group.
Q19. The IUPAC name of HCOOH is:
HCOOH का IUPAC नाम है:
A. Methanoic acid
B. Ethanoic acid
C. Propanoic acid
D. Oxalic acid
✔ Answer:
A. Methanoic acid / मेथेनोइक अम्ल
Explanation:
One carbon carboxylic acid → Methanoic acid.
Q20. Which acid is present in ant sting?
चींटी के डंक में कौन-सा अम्ल पाया जाता है?
A. Acetic acid
B. Lactic acid
C. Formic acid
D. Citric acid
✔ Answer:
C. Formic acid / फॉर्मिक अम्ल
Explanation:
Ant sting contains formic acid.
Q21. Which compound undergoes nucleophilic addition reaction?
कौन-सा यौगिक न्यूक्लियोफिलिक योग अभिक्रिया करता है?
A. Alkanes
B. Alkenes
C. Aldehydes
D. Alkynes
✔ Answer:
C. Aldehydes / एल्डिहाइड
Explanation:
Polar C=O group favours nucleophilic addition.
Q22. Which group increases acidity of carboxylic acid?
कौन-सा समूह अम्लीयता बढ़ाता है?
A. –CH₃
B. –C₂H₅
C. –Cl
D. –OH
✔ Answer:
C. –Cl
Explanation:
Electron-withdrawing groups increase acidity.
Q23. Which acid is least acidic?
निम्न में से सबसे कम अम्लीय कौन-सा है?
A. HCOOH
B. CH₃COOH
C. C₂H₅COOH
D. C₆H₅COOH
✔ Answer:
C. C₂H₅COOH
Explanation:
Alkyl groups donate electrons and reduce acidity.
Q24. Which compound gives Cannizzaro reaction?
कौन-सा यौगिक कैनिज़ारो अभिक्रिया देता है?
A. Acetaldehyde
B. Formaldehyde
C. Acetone
D. Propanone
✔ Answer:
B. Formaldehyde / फॉर्मल्डिहाइड
Explanation:
Aldehydes without α-hydrogen give Cannizzaro reaction.
Q25. Which compound contains α-hydrogen?
किस यौगिक में α-हाइड्रोजन होता है?
A. Formaldehyde
B. Benzaldehyde
C. Acetaldehyde
D. Formic acid
✔ Answer:
C. Acetaldehyde / एसीटैल्डिहाइड
Explanation:
CH₃–CHO has α-hydrogen.
Q26. Which acid is aromatic?
कौन-सा अम्ल एरोमैटिक है?
A. Acetic acid
B. Oxalic acid
C. Benzoic acid
D. Formic acid
✔ Answer:
C. Benzoic acid / बेंज़ोइक अम्ल
Explanation:
Benzoic acid contains benzene ring.
Q27. Which reagent converts aldehyde to alcohol?
कौन-सा अभिकर्मक एल्डिहाइड को ऐल्कोहॉल में बदलता है?
A. KMnO₄
B. NaBH₄
C. Fehling’s solution
D. Tollen’s reagent
✔ Answer:
B. NaBH₄
Explanation:
NaBH₄ reduces aldehydes to primary alcohols.
Q28. Which compound gives fruity smell?
कौन-सा यौगिक फल जैसी गंध देता है?
A. Aldehyde
B. Ketone
C. Ester
D. Acid
✔ Answer:
C. Ester / एस्टर
Explanation:
Esters are responsible for fruity odour.
Q29. Which acid is used as food preservative?
कौन-सा अम्ल खाद्य संरक्षक के रूप में प्रयोग होता है?
A. Oxalic acid
B. Benzoic acid
C. Formic acid
D. Citric acid
✔ Answer:
B. Benzoic acid / बेंज़ोइक अम्ल
Explanation:
Benzoic acid inhibits microbial growth.
Q30. Which compound shows keto–enol tautomerism?
कौन-सा यौगिक कीटो-इनॉल टॉटोमेरिज़्म दर्शाता है?
A. Methanal
B. Acetaldehyde
C. Benzaldehyde
D. Formic acid
✔ Answer:
B. Acetaldehyde / एसीटैल्डिहाइड
Explanation:
Presence of α-hydrogen enables tautomerism.
Q31. Which acid forms soap with NaOH?
कौन-सा अम्ल NaOH के साथ साबुन बनाता है?
A. Acetic acid
B. Fatty acids
C. Formic acid
D. Oxalic acid
✔ Answer:
B. Fatty acids / वसीय अम्ल
Explanation:
Saponification of fatty acids produces soap.
Q32. Which compound has highest boiling point?
किसका क्वथनांक सबसे अधिक होता है?
A. Aldehyde
B. Ketone
C. Alcohol
D. Carboxylic acid
✔ Answer:
D. Carboxylic acid
Explanation:
Strong hydrogen bonding increases boiling point.
Q33. Which reagent converts carboxylic acid to acid chloride?
कौन-सा अभिकर्मक अम्ल को अम्ल क्लोराइड में बदलता है?
A. SOCl₂
B. NaBH₄
C. Zn/HCl
D. NaOH
✔ Answer:
A. SOCl₂
Explanation:
Thionyl chloride converts –COOH to –COCl.
Q34. Which compound does NOT show hydrogen bonding?
कौन-सा यौगिक हाइड्रोजन बॉन्डिंग नहीं दर्शाता?
A. Alcohol
B. Acid
C. Ketone
D. Aldehyde
✔ Answer:
C. Ketone / कीटोन
Explanation:
Ketones lack –OH group.
Q35. Which acid is dibasic?
कौन-सा अम्ल द्विआधारी है?
A. Formic acid
B. Acetic acid
C. Oxalic acid
D. Benzoic acid
✔ Answer:
C. Oxalic acid / ऑक्सैलिक अम्ल
Explanation:
Oxalic acid has two –COOH groups.
Q36. Which compound gives positive Schiff’s test?
कौन-सा यौगिक शिफ़ परीक्षण देता है?
A. Ketone
B. Aldehyde
C. Acid
D. Alcohol
✔ Answer:
B. Aldehyde / एल्डिहाइड
Explanation:
Schiff’s reagent detects aldehydes.
Q37. Which compound is used in silvering of mirrors?
शीशों की सिल्वरिंग में कौन-सा यौगिक प्रयोग होता है?
A. Acetone
B. Formaldehyde
C. Acetic acid
D. Ethanol
✔ Answer:
B. Formaldehyde / फॉर्मल्डिहाइड
Explanation:
Formaldehyde reduces Ag⁺ to Ag.
Q38. Which acid is present in curd?
दही में कौन-सा अम्ल पाया जाता है?
A. Acetic acid
B. Lactic acid
C. Citric acid
D. Formic acid
✔ Answer:
B. Lactic acid / लैक्टिक अम्ल
Explanation:
Curd contains lactic acid due to fermentation.
Q39. Which compound undergoes aldol condensation?
कौन-सा यौगिक ऐल्डोल संघनन करता है?
A. Benzaldehyde
B. Formaldehyde
C. Acetaldehyde
D. Formic acid
✔ Answer:
C. Acetaldehyde / एसीटैल्डिहाइड
Explanation:
α-Hydrogen is required for aldol reaction.
Q40. Which acid is used in photography?
फोटोग्राफी में कौन-सा अम्ल प्रयोग होता है?
A. Oxalic acid
B. Acetic acid
C. Citric acid
D. Formic acid
✔ Answer:
A. Oxalic acid / ऑक्सैलिक अम्ल
Explanation:
Oxalic acid is used as a reducing agent.
Q41. Which compound gives pungent smell?
कौन-सा यौगिक तीखी गंध देता है?
A. Ketone
B. Aldehyde
C. Acid
D. Ester
✔ Answer:
B. Aldehyde / एल्डिहाइड
Explanation:
Lower aldehydes have sharp pungent odour.
Q42. Which acid is tricarboxylic?
कौन-सा अम्ल त्रिकार्बोक्सिलिक है?
A. Oxalic acid
B. Malonic acid
C. Citric acid
D. Formic acid
✔ Answer:
C. Citric acid / साइट्रिक अम्ल
Explanation:
Citric acid has three –COOH groups.
Q43. Which reagent reduces carboxylic acid to alcohol?
कौन-सा अभिकर्मक अम्ल को ऐल्कोहॉल में बदलता है?
A. NaBH₄
B. LiAlH₄
C. KMnO₄
D. HNO₃
✔ Answer:
B. LiAlH₄
Explanation:
LiAlH₄ is a strong reducing agent.
Q44. Which compound shows resonance?
कौन-सा यौगिक अनुनाद दर्शाता है?
A. Aldehyde
B. Ketone
C. Carboxylate ion
D. Alcohol
✔ Answer:
C. Carboxylate ion / कार्बोक्सिलेट आयन
Explanation:
Negative charge is delocalised by resonance.
Q45. Which acid sublimes on heating?
कौन-सा अम्ल गर्म करने पर उर्ध्वपातन करता है?
A. Benzoic acid
B. Acetic acid
C. Oxalic acid
D. Formic acid
✔ Answer:
A. Benzoic acid / बेंज़ोइक अम्ल
Explanation:
Benzoic acid sublimes on heating.
Q46. Which compound is used as preservative for biological samples?
जैविक नमूनों के संरक्षण में कौन-सा यौगिक प्रयोग होता है?
A. Acetone
B. Formaldehyde
C. Ethanol
D. Methanol
✔ Answer:
B. Formaldehyde / फॉर्मल्डिहाइड
Explanation:
Formalin preserves tissues.
Q47. Which acid forms anhydride easily?
कौन-सा अम्ल आसानी से एनहाइड्राइड बनाता है?
A. Formic acid
B. Acetic acid
C. Benzoic acid
D. Oxalic acid
✔ Answer:
B. Acetic acid / एसीटिक अम्ल
Explanation:
Acetic acid forms acetic anhydride.
Q48. Which compound gives pleasant smell?
कौन-सा यौगिक सुगंधित गंध देता है?
A. Acid
B. Aldehyde
C. Ketone
D. Ester
✔ Answer:
D. Ester / एस्टर
Explanation:
Esters are fragrant compounds.
Q49. Which acid is present in lemon?
नींबू में कौन-सा अम्ल पाया जाता है?
A. Acetic acid
B. Lactic acid
C. Citric acid
D. Oxalic acid
✔ Answer:
C. Citric acid / साइट्रिक अम्ल
Explanation:
Lemon contains citric acid.
Q50. Which compound does NOT reduce Tollens’ reagent?
कौन-सा यौगिक टॉलेंस अभिकर्मक को अपचयित नहीं करता?
A. Formaldehyde
B. Acetaldehyde
C. Benzaldehyde
D. Acetone
✔ Answer:
D. Acetone / एसीटोन
Explanation:
Ketones do not give Tollens’ test.

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