MCQ Questions

Free PDF Download of CBSE Chemistry Multiple Choice Questions for Class 12 with Answers Chapter 12 Aldehydes, Ketones, and Carboxylic Acids. Chemistry MCQs for Class 1 Chapter Wise with Answers PDF Download was Prepared Based on Latest Exam Pattern. Students can solve NCERT Class 12 Chemistry Aldehydes, Ketones and Carboxylic Acids MCQs Pdf with Answers to know their preparation level.

Aldehydes, Ketones and Carboxylic Acids Class 12 Chemistry MCQs Pdf

Chemistry MCQ Questions for Class 12 Pdf Question 1.

Answer/Explanation

Answer: d
Explaination:

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2. Reduction of aldehydes and ketones into hydrocarbons using zinc amalgam and cone. HCl is called:
(a) Cope reduction
(b) Dow reduction
(c) Wolff Kishner reduction
(d) Clemensen reduction

Answer/Explanation

Answer: d
Explaination:

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Chemistry MCQs for Class 12 Chapter wise Pdf Question 3. Acetophenone when reacted with base C₂H₅—ONa, yields a stable product:

Answer/Explanation

Answer: d
Explaination:

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Chemistry MCQs for Class 12 Chapterwise Question 4.

reacts with ch1oobenzene in presence of conc. H₂SO₄ produces

Answer/Explanation

Answer: c
Explaination:

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Chemistry MCQs for Class 12 with Answers Pdf Question 5. Propanoic acid with Br₂/P₄ yields a dibromo product. The structure will be

Answer/Explanation

Answer: c
Explaination: (c) ∵ α-hydrogens are replaced by Br atoms.

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Chemistry MCQs for Class 12 Question 6.

Answer/Explanation

Answer: b
Explaination:

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7. CH₃CHO and C₆H₅ CH₂CHO can be distinguished chemically by
(a) Benedict’s test
(b) Iodoform test
(c) Tollen’s reagent test
(d) Fehling’s solution test

Answer/Explanation

Answer: b
Explaination:

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8.

Answer/Explanation

Answer: c
Explaination:

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9. Which is most reactive towards Nucleophilic substitution reaction?
(a) Benzaldehyde
(b) Acetophenone

Answer/Explanation

Answer: c
Explaination:
(c) ∵ Nitro group is electron withdrawing.

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10. Which of the following is not soluble in NaHCO₃?
(a) 2, 4, 6-Trinitrophenol
(b) Benzoic acid
(c) o-Nitrophenol
(d) Benzene sulphonic acid

Answer/Explanation

Answer: c
Explaination: (c) o-Nitrophenol is weakly acidic.

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11. A single compound of the structure

is obtained from ozonolysis of which of the following compound?

Answer/Explanation

Answer: c
Explaination:

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12. Which among the given molecules can exhibit tautomerism?

(a) III only
(b) Both I and III
(c) Both I and II
(d) Both II and III

Answer/Explanation

Answer: a
Explaination:

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13. The product formed by the reaction of an aldehyde with a primary amine is
(a) Carboxylic acid
(b) Aromatic acid
(c) SchifTs base
(d) Ketone

Answer/Explanation

Answer: c
Explaination:

---

14.

Answer/Explanation

Answer:
Explaination:

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15. The correct order of increasing acidic strength is ____________ . [NCERT Exemplarl
(a) Phenol < Ethanol < Chloroacetic acid < Acetic acid
(b) Ethanol < Phenol < Chloroacetic acid < Acetic acid
(c) Ethanol < Phenol < Acetic acid < Chloroacetic acid
(d) Chloroacetic acid < Acetic acid < Phenol < Ethanol

Answer/Explanation

Answer: c
Explaination:
(c) It is because C₂H₅O^⊖ is least stable and chloroacetate ion is most stable.

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16. Compound

can be prepared by the reaction of __________ . [NCERT Exemplar]
(a) Phenol and benzoic acid in the presence of NaOH
(b) Phenol and benzoyl chloride in the presence of pyridine
(c) Phenol and benzoyl chloride in the presence of ZnCl₂
(d) Phenol and benzaldehyde in the presence of palladium

Answer/Explanation

Answer:
Explaination:

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17. Cannizaro’s reaction is not given by ____________ . [NCERT Exemplar]

Answer/Explanation

Answer: d
Explaination: (d) Because it has α-hydrogen.

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Note: In the following questions two or more options may be correct. (Q.18 to Q.21)
18. Which of the following compounds do not undergo aldol condensation? [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(b) and (d) because these do not have α-hydrogen.

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19. Treatment of compound

with NaOH solution yields [NCERT Exemplar]
(a) Phenol
(b) Sodium phenoxide
(c) Sodium benzoate
(d) Benzophenone

Answer/Explanation

Answer:
Explaination:

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20. Benzophenone can be obtained by ____________ . [NCERT Exemplar]
(a) Benzoyl chloride + Benzene + AlCl₃
(b) Benzoyl chloride + Diphenyl cadmium
(c) Benzoyl chloride + Phenyl magnesium chloride
(d) Benzene + Carbon monoxide + ZnCl₂

Answer/Explanation

Answer:
Explaination:

---

21. Correct order of decreasing reactivity of nucleophillic addition in case of HCHO, CH₃CHO and CH₃COCH₃ is
(a) CH₃ COH₃ > CH₃CHO > HCHO
(b) HCHO > CH₃CHO > CH₃COCH₃
(c) CH₃COCH₃ > HCHO > CH₃CHO
(d) CH₃CHO > HCHO > CH₃COCH₃

Answer

Answer: b

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22. The reagent with which both acetaldehyde and acetone react easily is
(a) Fehling’s reagent
(b) Grignard’s reagent
(c) Schiff’s reagent
(d) Tollen’s reagent

Answer

Answer: b

---

23.
The above chemical reaction represents
(a) Rosenmund’s reaction.
(b) Cannizaro’s reaction.
(c) Kolbe’s reaction,
(d) Etard’s reaction.

Answer

Answer: b

---

24. For distinction between pentan-2-one and pentan-3-one, which reagent can be employed?
(a) K₂Cr₂O₇/H⁺
(b) ZnHg/HCl
(c) NaOH/I₂
(d) AgNO₃/NH₄OH

Answer

Answer: c

---

25. Which of the following will undergo aldol condensation?
(a) CH₂ = CHCHO
(b) CH = CCHO
(c) C₆H₅CHO
(d) CH₃CH₂CHO

Answer

Answer: d

---

26. Compound ‘A’ C₅H₁₀O forms a phenyl hydrazone and gives a negative Tollen’s reagent test and iodoform test. On reduction with Zn+Hg/HCl, compound A gives n-pentane. The compound ‘A’ is
(a) Primary alcohol
(b) Aldehyde
(c) Secondary alcohol
(d) Ketone

Answer

Answer: b

---

27. Tert Butyl alcohol can be obtained by treating with CH3MgBr followed by hydrolysis
(a) HCHO
(b) CH₃CHO
(c) CH₃COCH₃
(d) CH₃CH₂CHO

Answer

Answer: c

---

28.
(a) 3-Nitrosalicylic acid
(b) 3, 5-Dinitrosalicylic acid
(c) m-Nitrobenzoic acid
(d) Picric acid

Answer

Answer: d

---

29. The end product (C) in the following reaction sequence is

(a) CH₃ — CH₂ COONa
(b) CH₂ = CH₂
(c) CH₃ — CH₃
(d) CH₂ = CH-COOH

Answer

Answer: b

---

30. Benzone acid is weaker than ……… but stronger than ………..
(a) p-toluic acid, o-toluic acid
(b) p-nitrobenzoic acid, p-toluic acid
(c) acetic acid, formic acid
(d) fomic acid, acetic acid

Answer

Answer: d

---

31. Which of the following is the correct representation for intermediate of nucleophilic addition reaction to the given carbonyl compound (A): [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(a) and (b) are correct intermediate.

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32. Match the common names given in Column I with the IUPAC names given in Column II. [NCERT Exemplar]

Column I (Common names)	Column II (IUPAC names)
(a) Cinnamaldehyde	(i) Pentanal
(b) Acetophenone	(ii) Prop-2-enal
(c) Valeraldehyde	(iii) 4-Methylpent-3-en-2-one –
(d) Acrolein	(iv) 3-Phenylprop-2-enal
(e) Mesityl oxide	(v) 1-Phenylethanone

Answer/Explanation

Answer:
Explaination:
(a) (iv)
(b) (v)
(c) (i)
(d) (ii)
(e) (iii)

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33. Match the acids given in Column I with their correct IUPAC names given in Column II. [NCERT Exemplar]

Column I (Acids)	Column II (IUPAC names)
(a) Phthalic acid	(i) Hexane-1,6-dioic acid
(b) Oxalic acid	(ii) Benzene-1,2-dicarboxylic acid
(c) Succinic acid	(iii) Pentane-1,5-dioic acid
(d) Adipic acid	(iv) Butane-1,4-dioic acid
(e) Glutaric acid	(v) Ethane-1,2-dioic acid

Answer/Explanation

Answer:
Explaination:
(a) (ii)
(b) (v)
(c) (iv)
(d) (i)
(e) (iii)

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34. Match the reactions given in Column I with the suitable reagents given in Column II. [NCERT Exemplar]

Column I (Reactions)	Column II (Reagents)
(a) Benzophenone → Diphenylmethane	(i) LiAlH4
(b) Benzaldehyde → 1-Phenylethanol	(ii) DIBAL—H
(c) Cyclohexanone → Cyclohexanol	(iii) Zn(Hg)/Conc. HCl
(d) Phenyl benzoate → Benzaldehyde	(iv) CH3MgBr

Answer/Explanation

Answer:
Explaination:
(a) (iii)
(b) (iv)
(c) (i)
(d) (ii)

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Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices. (Q.25 to Q.28)
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct but reason is wrong statement.
(d) Assertion is wrong but reason is correct statement.
(e) Assertion and reason both are correct statements but reason is not correct explanation of assertion.
35. Assertion: Formaldehyde is a planar molecule.
Reason: It contains sp² hybridised carbon atom. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(a) Assertion and reason both are correct and reason is correct explanation of assertion.

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36. Assertion: Compounds containing —CHO group are easily oxidised to corresponding carboxylic acids. Reason: Carboxylic acids can be reduced to alcohols by treatment with LiAlH4. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(e) Assertion and reason both are correct statements but reason is not correct explanation of assertion.

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37. Assertion: The a-hydrogen atom in carbonyl compounds is less acidic.
Reason: The anion formed after the loss of a-hydrogen atom is resonance stabilised. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(d) Assertion is wrong but reason is correct statement.

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38. Assertion: Aromatic aldehydes and formaldehyde undergo Cannizaro reaction.
Reason: Aromatic aldehydes are almost as reactive as formaldehyde. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(c) Assertion is correct but reason is wrong statement.

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39. Pentan-2-one can be distinguished from pentan-3-one by ____________ test.

Answer/Explanation

Answer:
Explaination: Iodoform

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40. The pKa of acetic acid is ____________ than that of phenol.

Answer/Explanation

Answer:
Explaination: lower

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41. Benzoate ion is more ____________ than acetate ion.

Answer/Explanation

Answer:
Explaination: stable

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42. Formic acid does not undergo HVZ reaction because it does not have ____________ .

Answer/Explanation

Answer:
Explaination: a-hydrogen

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43. Phenol does not liberate CO₂ with NaHCO₃. [True/False]

Answer/Explanation

Answer:
Explaination: True, because it is weakly acidic.

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44. All aldehydes turn SchifTs reagent pink. [True/False]

Answer/Explanation

Answer:
Explaination: True

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45.

Answer/Explanation

Answer:
Explaination: True

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46. [True/False]

Answer/Explanation

Answer:
Explaination: True

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47. Write IUPAC name of the following compound: [Delhi 2014(C)]

Answer/Explanation

Answer:
Explaination: 2-Methyl propanal.

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48. Write the structure of 3-hydroxybutanal. [Foreign 2013]

Answer/Explanation

Answer:
Explaination:

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49. Write the structure of 3-methylbutanal. [Delhi 2013]

Answer/Explanation

Answer:
Explaination:

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50. Write the IUPAC name of the compound. [Delhi 2014]

Answer/Explanation

Answer:
Explaination: 3-Amino butanal.

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51. Write the IUPAC name of the following compound: [Chennai 2019]

Answer/Explanation

Answer:
Explaination:

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52. Write the structure of the following compound: 3-oxopentanal. [Foreign 2011]

Answer/Explanation

Answer:
Explaination:

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53. Write the structure of p-Methylbenzaldehyde molecule. [AI 2014; Delhi 2013]

Answer/Explanation

Answer:
Explaination:

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54. Write the IUPAC name of the following compound: [Foreign 2014]

Answer/Explanation

Answer:
Explaination: 2-Hydroxy benzaldehyde.

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55. Write the structure of 4-chloropentan-2-one. [AI 2014; Delhi 2013]

Answer/Explanation

Answer:
Explaination:

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56. Write the structure of 4-methylpent-3-en-2-one. [Foreign 2013]

Answer/Explanation

Answer:
Explaination:

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57. Write the IUPAC name of the compound. [Delhi 2014]

Answer/Explanation

Answer:
Explaination: 4-Hydroxy-2-pentanone.

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58. Write the IUPAC name of [AI 2011(C)]

Answer/Explanation

Answer:
Explaination: 4-Methylpent-3-en-2-one

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59. How will you convert 3-hydroxybutanal from ethanol? Write chemical reaction.

Answer/Explanation

Answer:
Explaination:

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60. Complete the following chemical reaction:

Answer/Explanation

Answer:
Explaination:

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61. Write the chemical equations for the following chemical reactions:
Benzonitrile is converted to acetophenone.

Answer/Explanation

Answer:
Explaination:

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62. Ethanal is soluble in water. Why? [AI 2011]

Answer/Explanation

Answer:
Explaination:

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63. Which aldehyde does not give Fehling’s solution test?

Answer/Explanation

Answer:
Explaination:

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64. Write the IUPAC name of compound. [Delhi 2014]

Answer/Explanation

Answer:
Explaination:

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65. Write the IUPAC name of the following: [Delhi 2011(C)]

Answer/Explanation

Answer:
Explaination:

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66. Write the structure of 2-hydroxy benzoic acid. [AI 2014]

Answer/Explanation

Answer:
Explaination:

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67. Write the structural formula of 2-phenylethanoic acid. [Foreign 2013]

Answer/Explanation

Answer:
Explaination:

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68. Write the IUPAC name of [AI 2011(C)]

Answer/Explanation

Answer:
Explaination: 3-Bromo-5-chlorobenzoic acid

---

69. Write IUPAC name of the following compound: [AI 2014(C)]

Answer/Explanation

Answer:
Explaination: Isopropyl ethanoate (1-methyl ethyl propanoate).

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70. Write the IUPAC name of [Delhi 2011(C)]

Answer/Explanation

Answer:
Explaination: 3, 5-Dimethylphenylethanoate

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71. Higher carboxylic acids are practically insoluble in water. Give reason.

Answer/Explanation

Answer:
Explaination:
This is due to the increased hydrophobic interaction of hydrocarbon part.

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72. Arrange the following in increasing order of acidic character:
HCOOH, ClCH₂COOH, CF₃COOH, CCl₃COOH

Answer/Explanation

Answer:
Explaination:
HCOOH < ClCH₂COOH < CCl₃COOH < CF₃COOH

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73. Compare the strength of following acids:
(i) Formic acid,
(ii) Acetic acid,
(iii) Benzoic acid.

Answer/Explanation

Answer:
Explaination:
HCOOH > C₆H₅COOH > CH₃COOH

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74. Give some industrial uses of methanoic acid.

Answer/Explanation

Answer:
Explaination:
It is used in rubber, textile, leather, dying and electroplating industries.

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75. Draw the structural formula of 1-phenylpropan-l-one molecule.

Answer/Explanation

Answer:
Explaination:

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Free PDF Download of CBSE Chemistry Multiple Choice Questions for Class 12 with Answers Chapter 11 Alcohols, Phenols and Ethers. Chemistry MCQs for Class 12 Chapter Wise with Answers PDF Download was Prepared Based on Latest Exam Pattern. Students can solve NCERT Class 12 Chemistry Alcohols, Phenols and Ethers MCQs Pdf with Answers to know their preparation level.

Alcohols, Phenols and Ethers Class 12 Chemistry MCQs Pdf

1. The heating of phenyl methyl ether with HI produces
(a) Iodobenzene
(b) Phenol
(c) Benzene
(d) Ethyl chloride

Answer/Explanation

Answer: b
Explaination:

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2. Which of the following gives positive iodoform test?

Answer/Explanation

Answer: c
Explaination:

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3.

Answer/Explanation

Answer: c
Explaination:

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4. CH3—O—CH (CH3)2 + HI → Products is/are

Answer/Explanation

Answer: d
Explaination:

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5.

The product ‘Z’ is
(a) Benzaldehyde
(b) Benzoic acid
(c) Benzene
(d) Toluene

Answer/Explanation

Answer: b
Explaination:

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6. Which one of the following compounds has the most acid nature?

Answer/Explanation

Answer: d
Explaination:
(d) Phenol is most acidic in nature because phenoxide ion is stabilized by resonance.

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7. Among the following sets of reactants which one produces anisole?
(a) CH₃CHO : RMgX
(b) C₆H₅OH; NaOH, CH₃I
(c) C₆H₅OH, neutral FeCl₃
(d) C₆H₅ —CH₃; CH₃COCl; AlCl₃

Answer/Explanation

Answer: b
Explaination:

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8. The electrophile involved in Riemer-Tiemann reaction of phenol with CHCl₃ in presence of NaOH

Answer/Explanation

Answer: a
Explaination:

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9. Arrange the following in decreasing order of acidic character:

(a) IV > III > I > II
(b) II > IV > I > III
(c) I > II > III > IV
(d) III > I > II > IV

Answer/Explanation

Answer: d
Explaination:
(d) – Since, N02 and Cl are electron withdrawing but NO₂ > Cl.
– OCH₃ is more electron releasing due to +R effect than —CH₃ group, therefore, IV is least acidic.

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10.

(a) Etard reaction
(b) Gattermann Koch reaction
(c) Williamson synthesis
(d) Esterification

Answer/Explanation

Answer: c
Explaination:
(c) Williamson synthesis.

---

11. Identify ‘C’ in the following:

(a) Water
(b) Ethanol
(c) Propanone
(d) Cumene hydroperoxide

Answer/Explanation

Answer: c
Explaination:

---

12.

Answer/Explanation

Answer: a
Explaination:

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13. Find the product of the given reaction:

Answer/Explanation

Answer: a
Explaination:

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14.

Answer/Explanation

Answer: b
Explaination:

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15. Monochlorination of toluene in sunlight followed by hydrolysis with aq. NaOH yields. [NCERT Exemplar]
(a) o-Cresol
(b) m-Cresol
(c) 2, 4-Dihydroxytoluene
(d) Benzyl alcohol

Answer/Explanation

Answer: a
Explaination:

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16. How many alcohols with molecular formula C₄H₁₀O are chiral in nature? [NCERT Exemplar]
(a) 1
(b) 2
(c) 3
(d) 4

Answer/Explanation

Answer: a
Explaination:

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17. What is the correct order of reactivity of alcohols in the following reaction? [NCERT Exemplar]

(a) 1° > 2° > 3°
(b) P < 2° > 3°
(c) 3° > 2° > 1°
(d) 3° > 1° > 2°

Answer/Explanation

Answer: c
Explaination:
(c) 3° >2° > 1° is order of stability of carbocation .’. Reactivity follows the same order.

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18. CH₃CH₂OH can be converted into CH₃CHO by __________ . [NCERT Exemplar]
(a) catalytic hydrogenation
(b) treatment with LiAlH₄
(c) treatment with pyridinium chlorochromate
(d) treatment with KMnO₄

Answer/Explanation

Answer: c
Explaination:

---

19. IUPAC name of the compound

is _________ . [NCERT Exemplar]
(a) 1-methoxy-l-methylethane
(b) 2-methoxy-2-methylethane
(c) 2-methoxypropane
(d) isopropylmethyl ether

Answer/Explanation

Answer: c
Explaination:
(c) 2-methoxypropane

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20. Which of the following species can act as the strongest base?

Answer/Explanation

Answer: b
Explaination:
(b) ∵ ROH is weakest acid,
∴ RO^⊖ is strongest conjugate base.

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21. The correct order of boiling point of primary (1°), secondary (2°) and tertiary (3°) alcohols is
(a) 1° > 2° > 3°
(b) 3° > 2° > 1°
(c) 2° > 1° > 3°
(d) 2° > 3° > 1°

Answer

Answer: a

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22.
The above reaction is known as
(a) Williamson’s reaction.
(b) Hofmann’s synthesis.
(c) Mendies reaction,
(d) Darzen’s reaction.

Answer

Answer: d

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23. The correct acidic strength order of the following

(a) I > II > III
(b) III > I > II
(c) II > III > I
(d) I > III > II

Answer

Answer: b

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24. Which compound is predominantly formed when phenol is allowed to react with bromine in aqueous medium?
(a) Picric acid
(b) O-Bromophenol
(c) 2, 4, 6-Tribromophenol
(d) p-Bromophenol

Answer

Answer: c

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25. Phenols are more acidic than alcohols because
(a) Phenoxide ion is stablised by resonance
(b) Phenols are more soluble in polar solvents
(c) Phenoxide ion does not exhibit resonance
d) Alcohols do not lose H atoms at all

Answer

Answer: a

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26. The compound B is formed in the sequence of the reaction given below:

The compound B is
(a) Salicylaldehyde
(b) Benzoic acid
(c) Salicylic acid
(d) Cinnamic acid

Answer

Answer: c

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27. Which of the following reagents cannot be used to distinguish between phenol and benzyl alcohol?
(a) FeCl₃
(b) Litmus soln
(c) Br₂/CCl₄
(d) All of these

Answer

Answer: c

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28. Identify Z in the series

Answer

Answer: d

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29. 1-propanol and 2-propanol can be best dis¬tinguished by
(a) Oxidation with KMnO₄ followed by reaction with Fehling solution.
(b) Oxidation with acidic dichromate followed by reaction with Fehling solution.
(c) Oxidation by heating with copper followed by reaction with Fehling solution.
(d) Oxidation with concentrated H₂SO₄ followed by reaction with Fehling solution.

Answer

Answer: c

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30.
In the above sequence Z is
(a) Toluene
(b) Cresol
(c) Benzene
(d) Benzol

Answer

Answer: c

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31. The major organic product in the reaction, CH₃ — O — CH(CH₃)₂ + HI → product: is/are

Answer

Answer: a

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Note: In the following questions two or more options may be correct. (Q.21 to Q.23)
32. Which of the following are used to convert RCHO into RCH₂OH? [NCERT Exemplar]
(a) H₂/Pd
(b) LiAlH₄
(c) NaBH₄
(d) Reaction with RMgX followed by hydrolysis

Answer/Explanation

Answer:
Explaination:
(a), (b), (c) will convert RCHO into RCH₂OH.

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33. Which of the following reactions will yield phenol? [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(a), (b), (c) will give phenol, (d) will not give phenol because high temperature is needed.

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34. Which of the following reagents can be used to oxidise primary alcohols to aldehydes? [NCERT Exemplar]
(a) CrO₃ in anhydrous medium.
(b) KMnO₄ in acidic medium.
(c) Pyridinium chlorochromate.
(d) Heat in the presence of Cu at 573K.

Answer/Explanation

Answer:
Explaination:
(a), (c), (d) can be used. KMnO⁴ converts primary alcohol to carboxylic acids.

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35. Match the structures of the compounds given in Column I with the name of the compounds given in Column II. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(i) (d) (ii) (c) (iii) (J) (iv) (a) or quinol (v) (g) (vi) (b)

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36. Match the starting materials given in Column I with the products formed by these (Column II) in the reaction with HI. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(i) (d) (ii) (e) (iii) (b) (iv) (a)
In cleavage of ethers, higher alcohol and lower alkyl halide is formed except in tert. butyl methyl ether, in which (CH₃)₃ C+ is more stable so (CH₃)₃C-I and CH₃OH is formed. Anisole with HI gives phenol and CH₃I because phenoxide ion is stabilised by resonance.

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37. In the following question a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.
Assertion: Bond angle in ethers is slightly less than the tetrahedral angle.
Reason: There is a repulsion between the two bulky (—R) groups. [NCERT Exemplar]

Answer/Explanation

Answer:
Explaination:
(d) Assertion is wrong statement but reason is correct statement.

---

38. Phenol reacts with Br₂ in CS₂ to give _________ as major product.

Answer/Explanation

Answer:
Explaination: p-bromophenol

---

39. Phenol gives o and p-nitrophenol with _________ .

Answer/Explanation

Answer:
Explaination: dil. HNO₃

---

40. o-nitrophenol has _________ melting point than /j-nitrophenol.

Answer/Explanation

Answer:
Explaination: lower

---

41. Diethyl ether has dipole moment because they are bent molecule. [True/False]

Answer/Explanation

Answer:
Explaination: True

---

42. Ethers have lower boiling point than alcohol. [True/False]

Answer/Explanation

Answer:
Explaination:
True. It is due to weak van der Waals’ forces of attraction in ethers but intermolecular H-bonding in alcohol.

---

43. Dettol contains phenolic compound. [True/False]

Answer/Explanation

Answer:
Explaination: True, phenols are antiseptic in low concentration.

---

44. Write the IUPAC name of the given compound: [Foreign 2015]

Answer/Explanation

Answer:
Explaination: 3-methyl but-2-en-1-ol.

---

45. Write the IUPAC name of the given compound: [AI2015]

Answer/Explanation

Answer:
Explaination: 2-methyl propane 1, 3-diol.

---

46. Write the IUPAC name of the following compound: [Foreign 2012]

Answer/Explanation

Answer:
Explaination: Hex-4-en-3-ol.

---

47. Write IUPAC name of the following:

Answer/Explanation

Answer:
Explaination: 2, 2-Dimethyl propan-l-ol.

---

48. Write the IUPAC name of the following: [AI 2015 Bhubneshwar]

Answer/Explanation

Answer:
Explaination: l-Phenylpropan-2-ol.

---

49. Write IUPAC name of the compound: [Delhi 2015(C)]

Answer/Explanation

Answer:
Explaination: Butan-2-ol

---

50. Write IUPAC name of the given compound: [AI 2015 Patna]

Answer/Explanation

Answer:
Explaination: 2-methyl prop-2-en-l-ol.

---

51. Draw the structural formula of 2-methylpropan-2-ol molecule. [Delhi 2012]

Answer/Explanation

Answer:
Explaination:

---

52. Draw the structure of hex-l-en-3-ol compound.

Answer/Explanation

Answer:
Explaination:

---

53. How is ethanol obtained from 2-butene? [Delhi 2012]

Answer/Explanation

Answer:
Explaination:

---

54. Write the IUPAC name of the given compound: [Delhi 2015]

Answer/Explanation

Answer:
Explaination: 2, 5-Dinitro phenol.

---

55. Write IUPAC name of the given compound: [AI 2015 Guwahati]

Answer/Explanation

Answer:
Explaination: 2, 4-Dimethyl phenol.

---

56. Draw the structure of 2, 6-dimethylphenol. [AI 2011]

Answer/Explanation

Answer:
Explaination:

---

57. Write the IUPAC name of the given compound: [AI 2015]

Answer/Explanation

Answer:
Explaination:

---

58. Write IUPAC name of the given compound: [AI 2015 Chennai and Trivandrum]

Answer/Explanation

Answer:
Explaination: 1-Methoxypropan-2-ol.

---

59. Write the structure of the following compound: 2-ethoxy-2-methyl pentane

Answer/Explanation

Answer:
Explaination:

---

60. How is /-butyl alcohol obtained from acetone?

Answer/Explanation

Answer:
Explaination:

---

61. Write the chemical equation for the preparation of phenol from benzene using oleum and sodium hydroxide. [Delhi 2011(C)]

Answer/Explanation

Answer:
Explaination:

---

62. Why alcohols and phenols are soluble in water?

Answer/Explanation

Answer:
Explaination: This is due to their ability to form hydrogen bonds with water molecules.

---

63. Which of the following isomers is more volatile: o-nitrophenol or p-nitrophenol? [Delhi 2014]

Answer/Explanation

Answer:
Explaination: o-nitrophenol is more volatile, cone. H₂SO₄

---

64. How would you convert ethanol to ethene? [AI 2011]

Answer/Explanation

Answer:
Explaination:

---

65. Name a compound which is used as antiseptic as well as disinfectant.

Answer/Explanation

Answer:
Explaination:
0.2% solution of phenol is used as antiseptic, 2% solution of phenol is used as disinfectant.

---

66. Arrange the following in decreasing order of their acidic character: [Similar to AI 2017]

Answer/Explanation

Answer:
Explaination: (ii) > (iii) > (i)

---

67. Illustrate with examples the limitations of Williamson’s synthesis for the preparation of certain types of ethers.

Answer/Explanation

Answer:
Explaination:
Di-tertiary butyl ether cannot be prepared by Williamson’s synthesis because tertiary halides will undergo elimination reaction instead of substitution reaction.

---

68. What is the cause of large difference in boiling points of alcohols and ethers?

Answer/Explanation

Answer:
Explaination:
This is due to the presence of hydrogen bonding in alcohols but ether have weak van der Waals’ forces of attraction.

---

69. Convert anisole to p-bromoanisole. [Delhi 2015(C)]

Answer/Explanation

Answer:
Explaination:

---

70. How will you synthesise the following from appropriate alkene: [Uttarakhand 2019]

Answer/Explanation

Answer:
Explaination:

---

71. Show how you will synthesise the following alcohol prepared by reaction of a suitable Grignard reagent on methanal? [Uttarakhand 2019]

Answer/Explanation

Answer:
Explaination:

---

We hope the given Chemistry MCQs for Class 12 with Answers Chapter 11 Alcohols, Phenols, and Ethers will help you. If you have any query regarding CBSE Class 12 Chemistry Alcohols, Phenols, and Ethers MCQs Pdf, drop a comment below and we will get back to you at the earliest.

Check the below NCERT MCQ Questions for Class 10 English First Flight Chapter 6 The Hundred Dresses Part 2 with Answers Pdf free download. MCQ Questions for Class 10 English with Answers were prepared based on the latest exam pattern. We have provided The Hundred Dresses Part 2 Class 10 English MCQs Questions with Answers to help students understand the concept very well.

MCQ Questions for Class 10 English First Flight Chapter 6 The Hundred Dresses Part 2 with Answers

Question 1.
Who was more anxious for a reply?
(a) Peggy
(b) Maddie
(c) Miss Petronski
(d) Miss Mason

Answer

Answer: (b) Maddie

---

Question 2.
Who felt herself coward after Wanda left the school?
(a) Peggy
(b) Maddie
(c) Miss Petronski
(d) Miss Mason

Answer

Answer: (b) Maddie

---

Question 3.
What were Maddie’s thoughts as they go to Boggins Heights?
(a) tell her nobody would make fun of her name.
(b) tell that her nature was very rude.
(c) tell that she was ugly
(d) None of the Above

Answer

Answer: (a) tell her nobody would make fun of her name.

---

Question 4.
What did Mr. Petronski’s letter say?
(a) his daughter would not come to school any more.
(b) to appreciate the school.
(c) regarding poor performance of his child.
(d) None of the Above

Answer

Answer: (a) his daughter would not come to school any more.

---

Question 5.
Who was Miss Mason?
(a) Maths Teacher
(b) English Teacher
(c) Class Teacher
(d) Principal

Answer

Answer: (c) Class Teacher

---

Question 6.
What was the colour of the dress in Peggy’e drawing?
(a) red
(b) green
(c) blue
(d) white

Answer

Answer: (b) green

---

Question 7.
Wanda’s house was ____
(a) on a cliff
(b) on top of a hill
(c) by the river
(d) in the forest

Answer

Answer: (b) on top of a hill

---

Question 8.
What was the description of the house which Maddie thought to be Wanda’s house?
(a) Little white house
(b) Big white house
(c) Small green cottage
(d) Tiny Red hut

Answer

Answer: (a) Little white house

---

Question 9.
What was Maddie’s reaction on receiving the drawing?
(a) sad
(b) happy
(c) excited
(d) neutral

Answer

Answer: (a) sad

---

Question 10.
What was the tone of Wanda’s reply?
(a) Friendly
(b) Angry
(c) ungrateful
(d) hatred

Answer

Answer: (a) Friendly

---

Question 11.
Who was more anxious for a reply?
(a) Maddie
(b) Peggy
(c) Miss Mason
(d) All of them

Answer

Answer: (a) Maddie

---

Question 12.
What did they write in the letter?
(a) apology
(b) Her drawings and that she won
(c) asked about new city
(d) both 2 and 3

Answer

Answer: (d) both 2 and 3

---

Question 13.
What important decision does Maddie take?
(a) Unfriending Peggy
(b) visiting Wanda
(c) stop others from bullying
(d) all of the above

Answer

Answer: (c) stop others from bullying

---

Question 14.
What was Maddie reminded of by the Petronski’s house?
(a) how they teased her
(b) how she could stop all of it
(c) Wanda’s drawings
(d) Wanda’s dress; unironed but clean

Answer

Answer: (d) Wanda’s dress; unironed but clean

---

Question 15.
What did Maddie think of herself after the letter was read out loud?
(a) Grateful
(b) Lucky
(c) Hero
(d) Coward

Answer

Answer: (d) Coward

---

Question 16.
How would you describe Miss Mason’s feelings towards the class?
(a) Angry
(b) Upset
(c) Happy
(d) Cheerful

Answer

Answer: (b) Upset

---

Question 17.
what else was mentioned in the letter?
(a) her drawings
(b) her medal
(c) the school
(d) her funny name

Answer

Answer: (d) her funny name

---

Question 18.
Who wrote the letter received by Miss Mason?
(a) Wanda
(b) Wanda’s mother
(c) Wanda’s father
(d) Wanda’s brother

Answer

Answer: (c) Wanda’s father

---

We hope the given NCERT MCQ Questions for Class 10 English First Flight Chapter 6 The Hundred Dresses Part 2 with Answers Pdf free download will help you. If you have any queries regarding CBSE Class 10 English The Hundred Dresses Part 2 MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Check the below NCERT MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom with Answers Pdf free download. MCQ Questions for Class 9 Science with Answers were prepared based on the latest exam pattern. We have Provided Structure of the Atom Class 9 Science MCQs Questions with Answers to help students understand the concept very well. https://mcqquestions.guru/mcq-questions-for-class-9-science-chapter-4/

You can refer to NCERT Solutions for Class 9 Science Chapter 4 Structure of the Atom to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Structure of the Atom Class 9 MCQs Questions with Answers

Structure Of Atom Class 9 MCQ Question 1.
Which of the following correctly represents the electronic distribution in the Mg atom?
(a) 3, 8, 1
(b) 2, 8, 2
(c) 1, 8, 3
(d) 8, 2, 2

Answer

Answer: (b) 2, 8, 2

---

Structure Of Atom Class 9 MCQ With Answers Question 2.
Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in the discovery of
(a) electron
(b) proton
(c) nucleus in the atom
(d) atomic mass

Answer

Answer: (c) nucleus in the atom

---

Class 9 Science Chapter 4 MCQ Question 3.
The number of electrons in an element X is 15 and the number of neutrons is 16. Which of the following is the correct representation of the element?
(a) \(_{15}^{31}\)X
(b) \(_{16}^{31}\)X
(c) \(_{15}^{16}\)X
(d) \(_{16}^{15}\)X

Answer

Answer: (a) \(_{15}^{31}\)X

---

MCQ On Structure Of Atom Class 9 Question 4.
Which of the following are true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic mass = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (ii) and (iv)

Answer

Answer: (d) (ii) and (iv)

---

Structure Of Atom MCQ Class 9 Question 5.
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
(i) Rutherford’s atomic model
(ii) Thomson’s atomic model
(ii) Bohr’s atomic model
(a) (i), (ii) and (iii)
(b) (ii), (iii) and (i)
(c) (ii), (i) and (iii)
(d) (iii), (ii) and (i)

Answer

Answer: (c) (ii), (i) and (iii)

---

Class 9 Science Chapter 4 MCQ With Answers Question 6.
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
(a) 13
(b) 10
(c) 14
(d) 16

Answer

Answer: (b) 10

---

Class 9 Science Ch 4 MCQ Question 7.
Identify the Mg²⁺ ion from the figure where, n and p represent the number of neutrons and protons respectively.

Answer

Answer: (d)

---

MCQ Structure Of Atom Class 9 Question 8.
The first model of an atom was given by
(a) N. Bohr
(b) E. Goldstein
(c) Rutherford
(d) J.J. Thomson

Answer

Answer: (d) J.J. Thomson

---

Structure Of The Atom Class 9 MCQ Question 9.
An atom with 3 protons and 4 neutrons will have a valency of
(a) 3
(b) 7
(c) 1
(d) 4

Answer

Answer: (c) 1

---

Class 9 Structure Of Atom MCQ Question 10.
Which of the following statement is always correct?
(a) An atom has equal number of electrons and protons.
(b) An atom has equal number of electrons and neutrons.
(c) An atom has equal number of protons and neutrons.
(d) An atom has equal number of electrons, protons and neutrons.

Answer

Answer: (a) An atom has equal number of electrons and protons.

---

MCQ On Structure Of Atom Class 9 Question 11
Which of the following statements about Rutherford’s model of atom are correct?
(i) Considered the nucleus as positively charged.
(ii) Established that the a-particles are four times as heavy as a hydrogen atom.
(iii) Can be compared to solar system.
(iv) Was in agreement with Thomson’s model.
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) only (i)

Answer

Answer: (a) (i) and (iii)

---

MCQ Questions For Class 9 Science Chapter 4 Question 12.
Hydrogen exists in three isotopic forms, \(_{1}^{1}\)H, \(_{1}^{2}\)H, \(_{1}^{3}\)H known as protium, deuterium and tritium. Why are all the isotopes neutral in nature?
(a) Since neutrons are neutral in nature hence isotopes are electrically neutral.
(b) All the isotopes have one electron and one proton, hence they are neutral.
(c) All the isotopes have one proton and one neutron, hence they are neutral.
(d) Increasing number of protons in the isotopes make them neutral.

Answer

Answer: (b) All the isotopes have one electron and one proton, hence they are neutral.

---

Ch 4 Science Class 9 MCQ Question 13.
How many electrons are present in M-shell of an element with atomic number 20?
(a) 5
(b) 8
(c) 12
(d) 18

Answer

Answer: (b) 8

---

Chapter 4 Science Class 9 MCQ Question 14.
There are two atomic species X and Y, such that

Which of the following statements is true about X and Y?
(a) X and Y are isobars.
(b) X and Y have different chemical properties.
(c) X and Y have different physical properties.
(d) All of these.

Answer

Answer: (c) X and Y have different physical properties.

---

MCQ Of Structure Of Atom Class 9 Question 15.
The ion of an element has 3 positive charges. Mass number of the atom is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
(a) 13
(b) 10
(c) 14
(d) 16

Answer

Answer: (b) 10

---

Question 16.
An alpha particle is also known as:
(a) subatomic particle
(b) an unionised helium atom
(c) a neutral particle
(d) a doubly-charged helium ion

Answer

Answer: (d) a doubly-charged helium ion

---

Question 17.
There are three isotopes of carbon which are named as C-12, C-13 and C-14 out of which C-12 is the most abundant isotope. In the given structures of 3 isotopes, what will be the composition of the nucleus?

(a) C-12 : 6p + 6n, C-13 : 7p + 6n, C-14 : 8p + 6n
(b) C-12 : 6p + 6n, C-13 : 6p + 7n, C-14 : 6p + 8n
(c) C-12 : 6p + 6n, C-13 : 5p + 8n, C-14 : 7p + 7n
(d) C-12 : 6p + 6n, C-13 : 12p + 1n, C-14 : 5p + 9n

Answer

Answer: (b) C-12 : 6p + 6n, C-13 : 6p + 7n, C-14 : 6p + 8n

---

Question 18.
The charge on an electron is equal to:
(a) 1.6 × 10^-19 C of -ve charge
(b) 2.6 × 10^-19 C of -ve charge
(c) 1.6 × 10^-22 C of -ve charge
(d) 1.6 × 10^-23 C of -ve charge

Answer

Answer: (a) 1.6 × 10^-19 C of -ve charge

---

Question 19.
Which of the following isotope is used in the treatment of blood cancer?
(a) P-32
(b) I-131
(c) Co-60
(d) any of these

Answer

Answer: (a) P-32

---

Question 20.
Isobars do not differ in the number of
(a) protons
(b) electrons
(c) neutrons
(d) nucleons

Answer

Answer: (d) nucleons

---

Fill in the blanks

1. Rutherford’s a-particle scattering experiment led to the discovery of the ……………….

Answer

Answer: atomic nucleus

---

2. Isotopes have same ……………… but different ……………..

Answer

Answer: atomic number, mass number

---

3. Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be ………….. and ……………. respectively.

Answer

Answer: 0 and 1

---

4. The electronic configuration of silicon is …………… and that of sulphur is ……………..

Answer

Answer: 2, 8, 4, and 2, 8, 6

---

5. Cathode rays consist of negatively charged particles known as ………………

Answer

Answer: electrons

---

6. ……………. are the atoms containing same number of neutrons.

Answer

Answer: isotones

---

7. The outermost shell of an atom is known as its ……………..

Answer

Answer: valence shell

---

8. Alpha particles are helium nuclei (He²⁺) and have …………. mass and ……………. units charge.

Answer

Answer: 4u and +2

---

9. The maximum number of electrons in a shell is given by ……………..

Answer

Answer: 2n²

---

10. Neutrons were discovered by …………….

Answer

Answer: James Chadwick

---

Match the names of the scientists given the columns A with their contributions towards the understanding of the atomic structure as given in column B.

1.

Column A	Column B
(a) Ernest Rutherford	(i) Indivisibility of atoms
(b) J. J. Thomson	(ii) Stationary orbits
(c) Dalton	(iii) Concept of nucleus
(d) Neils Bohr	(iv) Discovery of electrons
(e) James Chadwick	(v) Atomic number
(f) E. Goldstein	(vi) Neutron
(g) Mosley	(vii) Canal rays

Answer

Answer:

Column A	Column B
(a) Ernest Rutherford	(iii) Concept of nucleus
(b) J. J. Thomson	(iv) Discovery of electrons
(c) Dalton	(i) Indivisibility of atoms
(d) Neils Bohr	(ii) Stationary orbits
(e) James Chadwick	(vi) Neutron
(f) E. Goldstein	(vii) Canal rays
(g) Mosley	(v) Atomic number

---

2.

Column A	Column B
(a) Ions	(i) Same mass number, different atomic numbers.
(b) Isobars	(ii) Same number of neutrons, different mass numbers.
(c) Isotopes	(iii) Formed by loss or gain of electron
(d) Isotones	(iv) Combining capacity of an atom.
(e) Valency	(v) Same atomic numbers, different mass numbers.

Answer

Answer:

Column A	Column B
(a) Ions	(iii) Formed by loss or gain of electron
(b) Isobars	(i) Same mass number, different atomic numbers.
(c) Isotopes	(v) Same atomic numbers, different mass numbers.
(d) Isotones	(ii) Same number of neutrons, different mass numbers.
(e) Valency	(iv) Combining capacity of an atom.

---

3.

Column A	Column B
Chlorine atom	2, 8
Sodium atom	2, 8, 7
Magnesium ion	2, 8, 2
Magnesium atom	2, 8, 1

Answer

Answer:

Column A	Column B
Chlorine atom	2, 8
Sodium atom	2, 8, 7
Magnesium ion	2, 8, 2
Magnesium atom	2, 8, 1

---

Answer the questions in one word:

1. Which symbols are used to represent different Bohr’s orbits?

Answer

Answer: K, L, M, N

---

2. Which isotope is used in the treatment of cancer?

Answer

Answer: Cobalt-60

---

3. What is the charge of anode rays?

Answer

Answer: positive

---

4. There are 14 protons and 13 neutrons in the nucleus of an atom. What is its mass number?

Answer

Answer: 27

---

5. Indicate the number of electrons, protons and neutrons in the element \(_{19}^{39}\)K.

Answer

Answer: e = 19, p = 19, n = 20

---

6. The atomic number of cation M²⁺ is 12. How many electrons are present in it?

Answer

Answer: 10

---

7. Which isotope of hydrogen is called protium?

Answer

Answer: \(_{1}^{1}\)H

---

8. Which particles determine the mass of an atom?

Answer

Answer: Protons, neutrons

---

Solve the crossword with the help of clues:

Across:
1. Part of atom responsible for mass.
3. Same mass number of species.
5. a-particle scattering experiment.
7. No. of valence electron in sodium.
Down:
2. Discovered the neutron.
4. Latest atomic model given by.
6. Negatively charged subatomic particle.
8. Positively charged substance particle.

Answer

Answer:

Across:
1. Nucleus
3. Isobar
5. Rutherford
7. One

Down:
2. Chadwick
4. Bohr
6. Electron
8. Proton

---

We hope the given NCERT MCQ Questions for Class 9 Science Chapter 4 Structure of the Atom with Answers Pdf free download will help you. If you have any queries regarding Structure of the Atom CBSE Class 9 Science MCQs Multiple Choice Questions with Answers, drop a comment below and we will get back to you soon.

Check the below NCERT MCQ Questions for Class 9 Science Chapter 3 Atoms and Molecules with Answers Pdf free download. MCQ Questions for Class 9 Science with Answers were prepared based on the latest exam pattern. We have Provided Atoms and Molecules Class 9 Science MCQs Questions with Answers to help students understand the concept very well. https://mcqquestions.guru/mcq-questions-for-class-9-science-chapter-3/

You can refer to NCERT Solutions for Class 9 Science Chapter 3 Atoms and Molecules to revise the concepts in the syllabus effectively and improve your chances of securing high marks in your board exams.

Atoms and Molecules Class 9 MCQs Questions with Answers

Atoms And Molecules Class 9 MCQ Question 1.
The chemical symbol for nitrogen gas is
(a) Ni
(b) N₂
(c) N⁺
(d) N

Answer

Answer: (b) N₂

---

Atoms And Molecules Class 9 MCQ With Answers Question 2.
The chemical symbol for sodium is
(a) So
(b) Sd
(c) NA
(d) Na

Answer

Answer: (d) Na

---

Class 9 Science Chapter 3 MCQ Question 3.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles of CO₂
(c) 2 moles of CaCO₃
(d) 10 moles of H₂O

Answer

Answer: (c) 2 moles of CaCO₃

---

Class 9 Atoms And Molecules MCQ Question 4.
Which of the following has maximum number of atoms?
(a) 18 g of H₂O
(b) 18 g of O₂
(c) 18 g of CO₂
(d) 18 g of CO₄

Answer

Answer: (d) 18 g of CO₄

---

Atom And Molecules Class 9 MCQ Question 5.
Which of the following correctly represents 360 g of water?
(i) 2 moles of H₂O
(ii) 20 moles of water
(iii) 6.022 × 10²³ molecules of water
(iv) 1.2044 × 10²⁵ molecules of water
(a) (i)
(b) (i) and (iv)
(c) (ii) and (iii)
(d) (ii) and (iv)

Answer

Answer: (d) (ii) and (iv)

---

MCQ On Atoms And Molecules Class 9 Question 6.
3.42 g of sucrose are dissolved in 18 g of water in a beaker. The number of oxygen atoms in the solution are
(a) 6.68 × 10²³
(b) 6.09 × 10²²
(c) 6.022 × 10²³
(d) 6.022 × 10²³21

Answer

Answer: (a) 6.68 × 10²³

---

MCQ Of Atoms And Molecules Of Class 9 Question 7.
A change in the physical state can be brought about
(a) only when energy is given to the system
(b) only when energy is taken out from the system
(c) when energy is either given to, or taken out from the system
(d) without any energy change

Answer

Answer: (c) when energy is either given to, or taken out from the system

---

Class 9 Science Ch 3 MCQ Question 8.
The relative molecular mass of Na₂S₂O₃.5H₂O is
(a) 250 amu
(b) 250 g
(c) 248 amu
(d) 248 g

Answer

Answer: (c) 248 amu

---

MCQ Atoms And Molecules Class 9 Question 9
Which of the following has maximum number of atom?
(a) 18 g H₂O
(b) 18 g of O₂
(c) 18 g of CO₂
(d) 18 g of CH₄

Answer

Answer: (d) 18 g of CH₄

---

Ch 3 Science Class 9 MCQ Question 10.
Percentage of calcium in calcium carbonate is
(a) 40
(b) 30
(c) 48
(d) 36

Answer

Answer: (a) 40

---

Atoms And Molecules MCQ Class 9 Question 11.
Which has maximum number of molecules?
(a) 1 g of CO₂
(b) 1 g of N₂
(c) 1 g of H₂
(d 1 g of CH₄

Answer

Answer: (c) 1 g of H₂

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Class 9 Chemistry Chapter 3 MCQ Question 12.
What mass of carbon dioxide (CO₂) will contain 3.011 × 10²³ molecules?
(a) 11.0 g
(b) 22.0 g
(c) 4.4 g
(d) 44.0 g

Answer

Answer: (b) 22.0 g

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Class 9 Chapter 3 Science MCQ Question 13.
The value of Avogadro’s constant is:
(a) 6.0 × 10²⁴
(b) 6.01 × 10²²
(c) 6.022 × 10²³
(d) 6.022 × 10^-23

Answer

Answer: (c) 6.022 × 10²³

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Class 9 Science Chapter 3 MCQ With Answers Question 14.
How many times an atom of sulphur is heavier than an atom of carbon?
(a) 32 times
(b) 12 times
(c) 8/3 times
(d) 12/32 times

Answer

Answer: (c) 8/3 times

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Chapter 3 Science Class 9 MCQ Question 15.
The number of oxygen atoms in 4.4 g of CO₂ is approx.
(a) 6 × 10²²
(b) 6
(c) 12 × 10²³
(d) 1.2 × 10²³

Answer

Answer: (d) 1.2 × 10²³

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Question 16.
Which of the following represents 12 u?
(a) Mass of 1 hydrogen atom
(b) Mass of C-12 atom
(c) Mass of 0-16 atom
(d) 1/12th of mass of C-12 atom.

Answer

Answer: (d) 1/12th of mass of C-12 atom.

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Question 17.
Which of the following would weigh the highest?
(a) 0.2 mole of sucrose (C₁₂H₂₂O₁₁)
(b) 2 moles of CO₂
(c) 2 moles of CaCO₃
(d) 10 moles of H₂O

Answer

Answer: (c) 2 moles of CaCO₃

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Question 18.
The molecule having an atomicity of 4 is:
(a) Sulphate molecule
(b) Ozone molecule
(c) Phosphorus molecule
(d) Methane molecule

Answer

Answer: (c) Phosphorus molecule

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Fill in the blanks

1. In a chemical reaction, the sum of the masses of the reactants and products remain unchanged. This is called ……………

Answer

Answer: Law of Conservation of Mass

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2. A group of atoms carrying a fixed charge on them is called …………..

Answer

Answer: Polyatomic ion

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3. The formula unit mass of Ca₃(PO₄)₂ is ……………

Answer

Answer: (3 × atomic mass of calcium) + (2 × atomic mass of phosphorus) + (8 × atomic mass of oxygen) = 310

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4. Formula of sodium carbonate is ………….. and that of ammonium sulphate is ……………

Answer

Answer: Na₂CO₃ (NH₄)₂ SO₄

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5. Elements are represented by symbols and molecules by …………….

Answer

Answer: Chemical formula

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6. The combining power of an element is known as its …………….

Answer

Answer: Valency

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7. An atom or a group of atoms which carries positive or negative charge is called an ……………..

Answer

Answer: ion

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8. The volume occupied by one mole of a gas under standard conditions of temperature and pressure is called ……………..

Answer

Answer: molar volume

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9. The number of atoms present in one molecule of the substance is called its ……………

Answer

Answer: atomicity

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10. Atomicity of H₂SO₄ is …………….

Answer

Answer: 7

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Match the following columns
1.

Column I	Column II
(a) 28 g of He	(i) 58.54
(b) 0.5 mole of O2	(ii) 7 mol
(c) Molecular mass of common salt	(iii) 60 g
(d) 1.5 mole of Ca	(iv) 16 g

Answer

Answer:

Column I	Column II
(a) 28 g of He	(ii) 7 mol
(b) 0.5 mole of O2	(iv) 16 g
(c) Molecular mass of common salt	(i) 58.54
(d) 1.5 mole of Ca	(iii) 60 g

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2.

Column I	Column II
(a) Sodium carbonate	(i) NaHCO3
(b) Sodium bicarbonate	(ii) Na3PO4
(c) Sodium sulphate	(iii) Na2CO3
(d) Sodium phosphate	(iv) Na2SO4

Answer

Answer:

Column I	Column II
(a) Sodium carbonate	(iii) Na2CO3
(b) Sodium bicarbonate	(i) NaHCO3
(c) Sodium sulphate	(iv) Na2SO4
(d) Sodium phosphate	(ii) Na3PO4

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3.

Column I	Column II
(a) Silver	(i) Na
(b) Sodium	(ii) Ag
(c) Gold	(iii) K
(d) Potassium	(iv) Au

Answer

Answer:

Column I	Column II
(a) Silver	(ii) Ag
(b) Sodium	(i) Na
(c) Gold	(iv) Au
(d) Potassium	(iii) K

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Answer the questions in one word:

1. Smallest particle which cannot be divided into simpler parts.

Answer

Answer: Parmanu (Atom)

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2. Which experiment led to the discovery of the atomic nucleus?

Answer

Answer: Rutherford’s alpha particle scattering experiment

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3. What is the mass of a proton and a neutron?

Answer

Answer: 1 amu

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4. What do the species \(_{1}^{3}\)A and \(_{2}^{3}\)B represent?

Answer

Answer: Isobars

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5. What is the formula of hydrogen carbonate?

Answer

Answer: HCO₃^–

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6. What is the chemical formula of aluminium sulphate?

Answer

Answer: Al₂(SO₄)₃

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7. What is the formula unit mass of CaCl₂?

Answer

Answer: 111 u

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8. What is the mass of 5 moles H₂O?

Answer

Answer: 90 g

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1. Complete the following crossword puzzle by using the name of the chemical elements. Use the data given in table mentioned below.

Answer

Answer:
Down:
2. Gold
3. Iron
5. Phosphorus
7. Hydrogen

Across:
1. Silver
4. Copper
6. Mercury
8. Lead

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