Please refer to Chapter 12 Organic Chemistry – Some Basic Principles and Techniques MCQ Class 11 Chemistry with answers below. These multiple-choice questions have been prepared based on the latest NCERT book for Class 11 Chemistry. Students should refer to MCQ Questions for Class 11 Chemistry with Answers to score more marks in Grade 11 Chemistry exams. Students should read the chapter Organic Chemistry – Some Basic Principles and Techniques and then attempt the following objective questions.

MCQ Questions Class 11 Chemistry Chapter 12 Organic Chemistry – Some Basic Principles and Techniques

The Organic Chemistry – Some Basic Principles and Techniques MCQ Class 11 Chemistry provided below covers all important topics given in this chapter. These MCQs will help you to properly prepare for exams.

Question. 1.2 g of an organic compound on Kjeldahl station liberates ammonia which consumes 30cm³ of 1 N HCI. The percentage of nitrogen in the organic compound is 
(a) 30
(b) 35
(c) 46.67
(d) 20.8       

Question. Identify the binary mixture(s) that can be separated into individual compounds, by differential extraction as shown in the given scheme.

(a) C₆H₅OH and C₆H₅ ,COOH
(b) C₆H₅COOH and C₆H₅CH₂OH
(c) C₆H₅CH₂OHand C₆H₅OH
(d) C₆H₅CH₂OHand C₆H₅CH₂COOH

Question. An organic compound on heating with CuO produces CO₂ but no water. The organic compound may be
(a) carbon tetrachloride 
(b) chloroform
(c) methane
(d) ethyl iodide   

Question. Match the following columns.

Codes
A B C D E
(a) 5 4 1 2 3
(b) 4 5 1 6 2
(c) 6 4 1 3 2
(d) 5 4 6 2 3
(e) 4 6 2 3 5

Question. Which of the following complex formation indicates presence of sulphur in the organic compound when sodiwn nitroprusside is added to sodium extract of the compound?
(a) Fe₄ [Fe(CN)₆]₃
(c) Fe₄ (CNS)₃
(b) Na₂ [Fe(NO)(CN)₅ ]
(d) Na₄ [Fe(CN)₅ NO₅]     

Question. Naphthalene can be easily purified by 
(a) sublimation
(b) crystallisation
(c) distillation
(d) vaporisation    

Question. Which one of the following compounds precipitate with AgNO₃ ?

Question. A mixture of camphor and benzoic acid can be separated by
(a) sublimation
(b) extraction with a solvent
(c) chemical method
(d) fractional crystallisation       

Question. Which of the following reagents will be fruitful for separating a mixture of nitrobenzene and aniline?
(a) Aq. NaHCO₃
(b) H₂O 
(c) Aq. HCl
(d) Aq. NaOH       

Question. KI in acetone undergoes S_N 2 reaction with each P,Q, R The rates of reaction vary as

(a) P > Q > R >S
(b) S >P >R >Q
(c) P >R > Q> S
(d) R >P > S> Q

Question. Fractional distillation is a process by which the separation of different fractions from mixture of solution is carried by making use which of the following property of the fractions ? 
(a) Freezing point
(b) Boiling point
(c) Melting point
(d) Solubility       

Question. On complete combustion, 0.246 g of an organic compound gives 0.198 g of CO₂ and 0.1014 g of H₂O. The ratio of carbon and hydrogen atoms in the compound is 
(a) 1 : 3
(b) 1 : 2
(c) 2: 5
(d) 2: 7     

Question. Which one of the following will most readily dehydrated in acidic solution?

Question. For the reaction represented by the equation. CX₄ + 2O₂ → CO₂ + 2X 2O.9.0 g of CX₄ completely reacts with 1.74 g of oxygen. The approximate molar mass of X will be 
(a) 20
(b) 40
(c) 60
(d) 80   

Question. In estimation of nitrogen, by Kjeldahl’s method, CuSO₄ acts as an 
(a) oxidising agent
(b) reducing agent
(c) catalysing agent
(d) hydrolysing agent     

Question. Which one of the following is an intermediate in the reaction of benzene with CH₃ Cl in the presence of anhydrous AlCI₃ ?

Question. Which of the substances is purified by sublimation ?
(a) Benzoic acid
(b) Camphor 
(c) Naphthalene
(d) All of these       

Question. On combustion, a gaseous hydrocarbon gives 0.72 g of water and 3.08 g of CO₂ . The empirical formula of the hydrocarbon is 
(a) C₂H₄
(b) C₃H₄
(c) C₆H₅
(d) C₇H₈   

Question. An oxygen contauung organic compound was found to contain 52% carbon and 13% hydrogen. Its vapour density is 23. The compound reacts with sodiwn metal to liberate hydrogen. A functional isomer of this compound is 
(a) ethanal
(b) methoxy methane
(c) methoxy ethane
(d) ethanol     

Question. The ease of nitration of the following three hydrocarbons follows the order

(a) II = III ,,, I
(b) II > I > III
(c) III > II > I
(d) I =Ul>II

Question. The sodium extract of an organic compound on acidification with acetic acid and addition of lead acetate solution gives a black precipitate. The organic compound contains
(a) nitrogen
(b) halogen 
(c) sulphur
(d) phosphorous       

Question. Which method is used to separate sugars ? 
(a) Fractional crystallisation
(b) Sublimation
(c) chromatography
(d) Benedict’s reagent     

Question. Which one of the following has the most nucleophilic nitrogen?

Question. During the fusion of an organic compound with sodium metal, nitrogen of the compound is converted into 
(a) NaNO₂ 
(b) NaNH₂
(c) NaCN
(d) NaNC       

Question. Lassaigne’s test for the detection of nitrogen fails in
(a) H₂N—CO—NHNH₂ · HCl 
(b) NH2—NH₂ · HCl
(c) NH₂—CO—NH₂
(d) C₆H₅—NH—NH₂ · HCl
(e) C₆H₅CONH₂       

Question. Consider the following compounds,

Arrange the above compounds in the con-ect order according to their reactivity towards electrophile.
(a) II > III > I
(b) III < I < II
(c) I > II > III
(d) l=dl > III

Question. Which of the following process is suitable for the purification of aniline? 
(a) Simple distillation
(b) Fractional distillation
(c) Fractional crystallisation
(d) Steam distillation
(e) Azeotropic distillation   

Question. Acidified sodium fusion extract on addition with ferric chloride solution gives confirm the presence of blood red colouration which
(a) Sand Cl
(b) N and S
(c) N
(d) S   

Question. Which of the following would react most readily with nucleophiles?

Question. Presence ofhalogen in organic compounds can be detected by using 
(a) Leibig’s test
(b) Duma’s test
(c) Kjeldahl’s test
(d) Beilstein’s test   

Question. For the purification, isolation and separation of organic compounds, the latest technique followed is 
(a) chromatography
(b) steam distillation
(c) fractional crystallisation
(d) sublimation     

Question. In the compound

Ring I Ring II
electrophilic substitution occurs at
(a) ortho/para-position at ring I
(b) meta-position at ring I
(c) ortholpara-position at ring II
(d) meta-position at ring II

Question. When SCN^– is added to an aqueous solution containing Fe(NO₃)_3, the complex ion produced is
(a) [Fe(OH₂)₂ (SCN)]²⁺
(b) [Fe(OH₂)₅ (SCN)]²⁺
(c) [Fe(OH₂)₈ (SCN)]²⁺
(d) [Fe(OH₂)(SCN)]⁶⁺       

Question. The best method to separate the mixture of ortho and para nitrophenol (1:1) is 
(a) vaporisation
(b) colour spectrum
(c) distillation
(d) crystallisation     

Question. The least active electrophile is

Question. 0.25 g of an organic compound on Kjeldahl’s analysis gave enough ammonia to just neutralise 10 cm₃ of 0.5 M H₂SO₄ . The percentage of nitrogen in the compound is
(a) 28
(b) 56
(c) 14
(d) 112
(e) 42       

Question. 29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl’s method and the evolved ammonia was absorbed in 20 mL of 0.1 M HCI solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralisation. The percentage of nitrogen in the compound is 
(a) 59.0
(b) 47.4
(c) 23.7
(d) 29.5   

Question. In Kjeldahl’s method, ammonia from 5g of food neutralises 30cm³ of 0.1 N acid. The percentage of nitrogen in the food is 
(a) 0.84
(b) 8.4
(c) 16.8
(d) 1.68       

Question. Which of the following will be easily nitrated?

Question. Which of the following statements is not true for S_NI reaction ? 
(a) 3° alkyl halides generally react through S_NI reaction
(b) The rate of the reaction does not depend upon the molar concentration of the nucleophile
(c) 1 ° alkyl halides generally react through S_NI reaction
(d) It is favoured by polar solvents       

Question. The ease of dehydrohalogenation of alkyl halides with alcoholic KOH is 
(a) 3° < 2° < 1°
(b) 3° > 2° > 1°
(c) 3° < 2° > 1°
(d) 3° > 2° < 1°       

Question. Dehydration of alcohol usually goes by 
(a) E₁ mechanism
(b) E₂ mechanism
(c) E₁ cb mechanism
(d) S_N2 mechanism   

Question.

The electrophile involved in the above reaction is
                                      ⊕
(a) dichloromethyl cation (CHCl₂)
(b) dichlorocarbene (:CCl₂)
(c) trichloromethyl anion (CCI₃)
                          ⊕
(d) fonnyl cation (CHO)

Question. Under identical conditions, the S_NI reaction will occur most efficiently with 
(a) tert-butyl chloride
(b) 1-chlorobutane
(c) 2-methyl-1-chloropropane
(d) 2- chlorobutane     

Question. The total number of possible alkenes by dehydrobromination of 3-bromo-3-cyclopentylhexane using alcoholic KOH is
(a) 1
(b) 3
(c) 5
(d) 7       

Question. The compound formed in the positive test for nitrogen with the Lassaigne’ s solution of an organic compound is
(a) Fe₄ [Fe(CN)₆]₃ 
(b) Na₃ [Fe(CN)₆ ]
(c) Fe(CN)₃
(d) Na₄ [Fe(CN)₅ NOS]     

Question. The decreasing order of nucleophilicity following nucleophiles is

(a) Ill, II, I, IV
(b) II, III, I, IV
(c) IV, III, II, I,
(d) I, n, III, IV

Question. Which one of the following compounds does not follow Markownikoffs rule? 
(a) CH₃—CH=CH₂
(b) CH₃CH=CHCH₃
(c) CH₃—CH—CH=CH₂
               l
             CH₃
(d) CH₃—CH₂—CH=CH₂     

Question. In S_NI reaction, the racemisation takes place. It is due to
(a) inversion configuration
(b) retention of configuration
(c) conversion of configuration
(d) Both (a) and (b)     

Question. An organic compound which produces a bluish green coloured flame on heating in presence of copper is
(a) chlorobenzene
(b) benzaldehyde 
(c) aniline
(d) benzoic acid   

Question. An organic compound having molecular mass 60 is found to contain 20% C, 6.67% H and 46.67% N while rest is oxygen. On heating, it gives NH₃ along with a solid residue. The solid residue gives violet colour with alkaline copper sulphate solution. The compound is 
(a) CH₃CH₂CONH₂
(b) (NH₂)₂ CO
(c) CH₃CONH₂
(d) CH₃NCO     

Question. Na₂S+ Na₂ [Fe(CN)₅ NO]→ purple colour. It is due to
(a) Na₄ [Fe(CN)₃ NOS]
(b) Na₃ [Fe(CN)₅ NOS]
(c) Na₄ [Fe(CN)₅ NO]
(d) Na₄ [Fe(CN)₅ NOS]       

Question. 5.6 g of an organic compound on burning with excess of oxygen gave 17.6 g of CO₂ and 7.2 g of H₂O. The organic compound is 
(a) C₆H₆
(b) C₄H₈
(c) C₃H₈
(d) CH₃COOH
(e) CH₃CHO   

Question. I. CH₃CH₂Br →^LAH C₂H₆ and 
II. (CH₃)₃ CBr →^LAH alkene,
The reason for this is
(a) (I) S_N2, (II) E₁ mechanism
(b) (I) S_N1, (II) E₂ mechanism
(c) (I) S_N1, (II) E₁ mechanism  
(d) (I) S_N2 , (JI) E₂ mechanism     

Question. Vinyl chloride undergoes
(a) Only addition reactions
(b) Only elimination reactions
(c) Both (a) and (b)
(d) substitution reactions     

Question. Which of the following cannot undergo nucleophilic substitution under ordinary conditions ? 
(a) Chlorobenzene
(b) Tert-butylchloride
(c) Isopropyl chloride
(d) None of the above         

Question. Protic solvent is
(a) diethyl ether
(c) acetone
(b) n-hexane
(d) ethanol     

Question. Arrange the following compounds in order of their decreasing reactivity towards an electrophile, E^⊕ . 
I. Chlorobenzene
II. 2, 4-dinitrochlorobenzene
III. p-nitrochlorobenzene
(a) III > II > I
(c) I > III > II
(b) II > III > I
(d) I > II > III     

Question. C₂H₅Cl + aq. NaOH → C₂H₅OH + NaCl this reaction is 
(a) electrophilic substitution ofl order
(b) electrophilic substitution of II order
(c) nucleophilic substitution ofl order
(d) nucleophilic substitution of II order     

Question. 0.765 g of an acid gives 0.535 g of CO₂ and 0.138 g of H₂O. Then, the ratio of the percentage of carbon and hydrogen is
(a) 19 : 2
(b) 18 : 11
(c) 20 : 17
(d) 1   : 7   

Question. Liebig’s test is used to estimate 
(a) H
(b) C
(c) Both C and H
(d) N         

Question. How much of sulphur is present in an organic compound, if 0.53 g of the compound gave 1.158 g of BaSO₄ on analysis? 
(a) 10%
(b) 15%
(c)20%
(d) 25%
(e) 30%     

Question. Conversion of chlorobenzene to phenol involves
(a) electrophilic substitution 
(b) nucleophilic substitution
(c) free radical substitution
(d) electrophilic addition       

Question. During nitration of benzene, the attacking electrophile is
(a) NO^–₃
(b) NO^–₂
(c) NO⁺₂
(d) HNO₃       

Question. The function of AlCl₃ in Friedel-Craft’s reaction is
(a) to absorb HCI 
(b) to absorb water
(c) to produce nucleophile
(d) to produce electro phi le     

Question. Which of the following solvents are aprotic?
I. NH₃
II. SO₂
III. CH₃CN
IV. CH₃CO₂H 
(a) I, II, III
(b) I, III, IV
(c) II, III
(d) I, III       

Question. The Kolbe’s electrolysis proceeds via
(a) nucleophilic substitution mechanism
(b) electrophilic addition mechanism
(c) free radical mechanism
(d) electrophilic substitution reaction     

Question. Grignard reagent adds to
(a) C = 0
{b) —C= N
(c) C = S
(d) All of these       

Question. Dehydration of alcohol is an example of which type of reaction ? 
(a) Substitution
(b) Elimination
(c) Addition
(d) Rearrangement       

Question. Which of the following is arranged according to the nature indicated ? 
(a) Electrophile – NO₂⁺ , Br⁺,
            Nucleophile -CH₃ OH, N^–₃
(b) Electrophile – NO⁺₂ , CH₃OH,
            Nucleophile – Br⁺, N^–₃
(c) Electrophile – CH₃OH,N^–₃ .
           Nucleophile – N⁺₂ , Br⁺
(d) Electrophile – Br⁺ , N^–₃ ,
           Nucleophile -CH₃OH, NO₂           

Question. Reaction of methyl bromide with aqueous sodium hydroxide involves 
(a) racemisation
(b) S_NI mechanism
(c) retention of configuration
(d) S_N2 mechanism     

Question. In electrophilic aromatic substitution reaction, the nitro group is meta-directing because it 
(a) decreases electron density at ortho and para-positions
(b) decreases electron density at meta-position
(c) increases electron density at meta-position
(d) increases electron density at ortho and para-positions   

Question. The electrophile involved in the sulphonation of benzene is
(a) SO⁺₃
(b) SO^2-₃
(c) H₃O⁺
(d) SO₃     

Question. In which of the following ways, does the hydride ion tend to function ? 
(a) An electrophile
(b) A nucleophile
(c) A free radical
(d) An acid       

Question. Following reaction,
(CH₃)₃ CBr + H₂O → (CH₃)₃  COH + HBr
is an example of
(a) elimination reaction
(b) free radical substitution
(c) nucleophilic substitution
(d) electrophilic substitution   

Question. Formation of cyanohydrin from a ketone is an example of
(a) electrophilic addition 
(b) nucleophilic addition
(c) electro phi lie substitution
(d) nucleophilic substitution       

Question. RX + I^– →R – I+x^– is an example of ……. reaction.
(a) nucleophilic addition 
(b) nucleophilic substitution
(c) electrophilic addition
(d) elimination             

Question. The reaction,
         O                     O
         ll                      ll
    R—C—X—Nu^– → R—C—Nu+X^–
fastest when Xis
(a) OCOR
(b) OC₂H₅
(c) NH₂
(d) Cl     

Question. Which of the following is least reactive towards nucleophilic substitution reaction?
(a) (CH₃)₃ C—Cl
(b) CH₂=CHCl
(c) CH₃CH₂Cl
(d) CH₂=CHCH₂CI         

Question. Which of the following is an electrophile? 
(a) H₂O
(b) SO₃
(c) NH₃
(d) ROR     

Question. The following compound will undergo substitution more readily than benzene electrophilic
(a) nitrobenzene
(b) benzoic acid
(c) benzaldehyde
(d) phenol         

Question. Nitration of benzene is
(a) electrophilic substitution
(b) electrophilic addition
(c) nucleophilic substitution
(d) nucleophilic addition       

Question. The ammonia evolved from the treatment of 0.30 g of an organic compound for the estimation of nitrogen was passed in 100 mL of 0.1 M sulphuric acid. The excess of acid required 20 mL of 0.5 M sodium hydroxide solution for complete neutralisation. The organic compound is
(a) acetamide 
(b) benzamide
(c) urea
(d) thiourea       

Question. Which of the following is most reactive towards nucleophilic substitution reaction ? 
(a) CH₂ = CH—Cl
(b) C₆H₅Cl
(c) C₆H₅CH₂Cl
(d) ClCH₂—CH = CH₂     

Question. Alkyl halide can be converted into alkene by 
(a) nucleophilic substitution reaction
(b) elimination reaction
(c) Both (a) and (b)
(d) rearrangement     

Question. In the nucleophilic substitution reactions (S_N2 or S_NI), the reactivity of alkyl halides follows the sequence 
(a) R – I > R – Br > R – Cl > R – F
(b) R – CI > R – F > R – Br> R – I
(c) R – F > R – Cl > R – Br > R – I
(d) R – I > R – F > R – Cl > R – Br     

Question. Quantitative measurement of nitrogen in an organic compound is done by the method 
(a) Berthelot method
(b) Beilstein’s method
(c) Lassaigne’s test
(d) Kjeldahl’s method       

Question. The reaction of sodium ethoxide with iodoethane to form diethyl ether is termed as 
(a) electrophilic substitution
(b) nucleophilic substitution
(c) electrophilic addition
(d) radical substitution     

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