JEE Chemistry Organic Chemistry Some Basic Principles and Techniques MCQs Set 03

Question. In Kjeldahl’s method for the estimation of N₂ , potassium sulphate and copper sulphate are used. On the basis of their functions which of the following statement(s) is/are correct?
(i) Potassium sulphate raises the bpt. and ensures complete reaction.
(ii) Copper sulphate acts as catalyst.
(iii) Potassium sulphate acts as catalyst and copper sulphate raises the bpt.
(a) (i) and (ii) are correct
(b) None is correct
(c) Only (iii) is correct
(d) Only (ii) is correct

Answer: A

Question. In the estimation of carbon and hydrogen by combustion method which of the following is/are correct ?
(i) A spiral of copper is introduced at the right extreme of combustion tube if the organic compound contains nitrogen.
(ii) A spiral of silver is introduced if the organic compound contains halogens.
(iii) The copper oxide in the combustion tube is replaced by lead chromate if the organic compound contains sulphur.
(a) All are correct
(b) (i) and (iii) are correct
(c) (i) and (ii) are correct
(d) (ii) and (iii) are correct

Answer: A

Question.
Assertion : A primary suffix indicates the type of linkage in the carbon atom.
Reason : CN is a Primary suffix
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question.
Assertion : The general formula for a dihydric alcohol is C_nH_2n(OH)₂
Reason : Ethylene glycol is a dihydric alcohol.
(a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question.
Assertion : Chain isomerism is observed in compounds containining four or more than four carbon atoms
Reason : Only alkanes show chain isomerism.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question.
Assertion : But-1-ene and 2-methylprop-1-ene are position isomers.
Reason : Position isomers have same molecular formula but differ in position of functional group or C = C.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question.
Assertion : Aniline is better nucleophile than anilium ion.
Reason : Anilium ion have +ve charge
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) None of these

Answer: A

Question.
Assertion : Different number of electron pairs are present in resonance structures.
Reason : Resonance structures differ in the location of electrons around the constituent atoms.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question.
Assertion : Energy of resonance hybrid is equal to the average of energies of all canonical forms.
Reason : Resonance hybrid cannot be presented by a single structure.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question.
Assertion : Simple distillation can help in separating a mixture of propan-1-ol (boiling point 97°C) and propanone (boiling point 56°C).
Reason : Liquids with a difference of more thatn 20°C in their boiling points can be separated by simple distillation
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question.
Assertion : Components of a mixture of red and blue inks can be separated by distributing the components between stationary and mobile phases in paper chromatography.
Reason : The coloured components of inks migrate at different rates because paper selectively retains different components according to the difference in their partition between the two phases
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question.
Assertion : Sulphur present in an organic compound can be estimated quantitatively by Carius method.
Reason : Sulphur is separated easily from other atoms in the molecule and gets precipitated as light yellow solid
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. The number of possible open chain (acyclic) isomeric compounds for molecular formula C₅H₁₀ would be
(a) 6
(b) 8
(c) 7
(d) 5

Answer: A

Question. The compound C₄H1₀O can show
(a) All of these
(b) functional isomerism
(c) metamerism
(d) position isomerism

Answer: A

Question. Which pair of isomerism is not possible together?
(a) Metamerism and functional
(b) Metamerism and chain
(c) Geometrical and optical
(d) Ring-chain and functional

Answer: A

Question. In Lassaigne’s test, the organic compound is fused with a piece of sodium metal in order to
(a) convert the covalent compound into a mixture of ionic compounds
(b) increase the reactivity of the compound
(c) decrease the melting point of the compound
(d) increase the ionisation of the compound

Answer: A

Question. The most suitable method for separtion of a 1 : 1 mixture of ortho and para nitrophenols is
(a) Steam distillation
(b) Chromatography
(c) Sublimation
(d) Crystallization

Answer: A

Question. The molecular mass of an organic compound which contains only one nitrogen atom can be
(a) 73
(b) 146
(c) 152
(d) 76

Answer: A

Question. Butanone is a four-carbon compound with the functional group –
(a) ketone
(b) carboxylic acid
(c) aldehyde.
(d) alcohol.

Answer: A

Question. The functional group present in CH₃COOC₂H₅ is
(a) ester
(b) ketonic
(c) aldehydic
(d) carboxylic

Answer: A

Question. Which of the following compounds contains 1°, 2°, 3° as well as 4° carbon atoms ?
(a) 2,2,3-trimethyl pentane
(b) 2-methyl pentane
(c) Neopentane
(d) 2,3-dimethyl butane

Answer: A

Question. The number of secondary hydrogens in 2, 2-dimethylbutane is
(a) 2
(b) 6
(c) 8
(d) 4

Answer: A

Question. The compound which has one isopropyl group is
(a) 2- Methypentane
(b) 2, 2, 3- Trimethylpentane
(c) 2, 2 - Dimethylpentane
(d) 2, 2, 3, 3 - Tetramethylpentane

Answer: A

Question. Which of the following statements is false for isopentane ?
(a) It has a carbon which is not bonded to hydrogen
(b) It has one CH group
(c) It has one CH₂ group
(d) It has three CH₃ groups

Answer: A

Question. The number of primary, secondary and tertiary carbons in 3, 4-dimethylheptane are respectively
(a) 4, 3 and 2
(b) 4, 2 and 3
(c) 2, 3 and 4
(d) 3, 4 and 2

Answer: A

Question. The number of primary, secondary, tertiary and quaternary carbons in neopentane are respectively
(a) 4, 0, 0 and 1
(b) 4, 3, 2 and 1
(c) 5, 0, 0 and 1
(d) 4, 0, 1 and 1

Answer: A

Question. What is the IUPAC name of t-butyl alcohol
(a) 2–Methyl-propan–2-ol
(b) Propanol-2
(c) Butanol–2
(d) Butanol–1

Answer: A

Question. The IUPAC name of CH₃COCH (CH₃)₂ is -
(a) 3-methyl-2-butanone
(b) 4-methylisopropyl ketone
(c) 2-methyl-3-butanone
(d) isopropyl methyl ketone

Answer: A

Question. Which of the following statements is false for isopentane
(a) It has a carbon which is not bonded to hydrogen
(b) It has one CH group
(c) It has one CH₂ group
(d) It has three CH₃ groups

Answer: A

Question. The IUPAC name of the compound CH₃OCH₂CH₂CH₂OCH₂CH₃ is
(a) 3-ethoxy-1-methoxypropane
(b) 1-ethoxy-3-methoxypropane
(c) 2, 5-dioxyhexane
(d) ethoxypropane oxymethane

Answer: A