General Organic Chemistry & Isomerism · JEE Main previous year questions

2019 15 questions

1. Q692019 · 12 Apr 2019 · Shift 1

   An organic compound 'A' is oxidized with ${\text{Na}}_2{\text{O}}_2$ followed by boiling with ${\text{HNO}}_3$. The resultant solution is then treated with ammonium molybdate to yield a yellow precipitate. Based on above observation, the element present in the given compound is:

   1. A.Fluorine
   2. B.Phosphorus
   3. C.Nitrogen
   4. D.Sulphur
   Show answer

   Answer: B

2. Q862019 · 12 Apr 2019 · Shift 1

   The correct sequence of thermal stability of the following carbonates is :

   1. A.${\text{BaCO}}_3<{\text{SrCO}}_3<{\text{CaCO}}_3<{\text{MgCO}}_3$
   2. B.${\text{MgCO}}_3<{\text{CaCO}}_3<{\text{SrCO}}_3<{\text{BaCO}}_3$
   3. C.${\text{BaCO}}_3<{\text{CaCO}}_3<{\text{SrCO}}_3<{\text{MgCO}}_3$
   4. D.${\text{MgCO}}_3<{\text{SrCO}}_3<{\text{CaCO}}_3<{\text{BaCO}}_3$
   Show answer

   Answer: B

3. Q612019 · 12 Apr 2019 · Shift 2
   
   1. A.$120^{\circ }$
   2. B.$58^{\circ }$
   3. C.$151^{\circ }$
   4. D.$149^{\circ }$
   Show answer

   Answer: D

4. Q622019 · 12 Apr 2019 · Shift 2

   An 'Assertion' and a 'Reason' are given below. Choose the correct answer from the following options : Assertion (A) : Vinyl halides do not undergo nucleophilic substitution easily. Reason (R) : Even though the intermediate carbocation is stabilized by loosely held p-electrons, the cleavage is difficult because of strong bonding.

   1. A.Both (A) and (R) are correct statements but (R) is not the correct explanation of (A)
   2. B.Both (A) and (R) are correct statements and (R) is the correct explanation of (A)
   3. C.(A) is correct statement but (R) is a wrong statement
   4. D.Both (A) and (R) are wrong statements.
   Show answer

   Answer: C

5. Q632019 · 12 Apr 2019 · Shift 2
   
   1. A.3, 5-dimethyl-4-propylhept-1-en-6-yne
   2. B.3-methyl-4-(3-methylprop-1-enyl)-1-heptyne
   3. C.3-methyl-4-(1-methylprop-2-enyl)-1-heptene
   4. D.3,5-dimethyl-4-propylhept-6-en-1-yne
   Show answer

   Answer: A

6. Q732019 · 10 Apr 2019 · Shift 1

   The principle of column chromatography is :

   1. A.Gravitational force.
   2. B.Capillary action.
   3. C.Differential adsorption of the substances on the solid phase.
   4. D.Differential absorption of the substances on the solid phase.
   Show answer

   Answer: C

7. Q822019 · 10 Apr 2019 · Shift 1
   
   1. A.III < II < I
   2. B.III < I < II
   3. C.II < I < III
   4. D.I < III < II
   Show answer

   Answer: B

8. Q672019 · 10 Apr 2019 · Shift 2

   In chromatography, which of the following statements is incorrect for ${\mathrm{R}}_{\mathrm{f}}$ ?

   1. A.${\mathrm{R}}_{\mathrm{f}}$ value depends on the type of chromatography.
   2. B.Higher ${\mathrm{R}}_{\mathrm{f}}$ value means higher adsorption.
   3. C.${\mathrm{R}}_{\mathrm{f}}$ value is dependent on the mobile phase.
   4. D.The value of ${\mathrm{R}}_{\mathrm{f}}$ can not be more than one.
   Show answer

   Answer: B

9. Q782019 · 10 Apr 2019 · Shift 2

   Which of these factors does not govern the stability of a conformation in acyclic compounds?

   1. A.Angle strain
   2. B.Torsional strain
   3. C.Electrostatic forces of interaction
   4. D.Steric interactions
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   Answer: A

10. Q812019 · 10 Apr 2019 · Shift 2

    The increasing order of nucleophilicity of the following nucleophiles is : (a) $\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{O}}_2^{-}$ (b) ${\mathrm{H}}_2\mathrm{O}$ (c) $\mathrm{C}{\mathrm{H}}_3\mathrm{S}{\mathrm{O}}_3^{-}$ (d) $\overline{\mathrm{O}}\mathrm{H}$

    1. A.(b) < (c) < (a) < (d)
    2. B.(b) < (c) < (d) < (a)
    3. C.(a) < (d) < (c) < (b)
    4. D.(d) < (a) < (c) < (b)
    Show answer

    Answer: A

11. Q642019 · 9 Apr 2019 · Shift 1

    The organic compound that gives following qualitative analysis is : $$\begin{array}{lll}& \text{Test}& \text{Inference}\\ \text{(a)}& \text{Dil. HCl}& \text{Insoluble}\\ \text{(b)}& \text{NaOH solution}& \text{soluble}\\ \text{(c)}& \mathrm{B}{\mathrm{r}}_2\text{/water}& \text{Decolourization}\end{array}$$

    1. A.${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH}$ (phenol)
    2. B.${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{N}{\mathrm{H}}_2$ (aniline)
    3. C.${\mathrm{C}}_6{\mathrm{H}}_{11}\mathrm{N}{\mathrm{H}}_2$ (cyclohexylamine)
    4. D.${\mathrm{C}}_6{\mathrm{H}}_{11}\mathrm{OH}$ (cyclohexanol)
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    Answer: A

12. Q712019 · 9 Apr 2019 · Shift 1

    The correct IUPAC name of the following compound is : [Benzene ring with $\mathrm{N}{\mathrm{O}}_2$ at one position, $\mathrm{C}{\mathrm{H}}_3$ para to $\mathrm{N}{\mathrm{O}}_2$, and Cl ortho to $\mathrm{C}{\mathrm{H}}_3$ (meta to $\mathrm{N}{\mathrm{O}}_2$)]

    1. A.2-methyl-5-nitro-1-chlorobenzene
    2. B.2-chloro-1-methyl-4-nitrobenzene
    3. C.3-chloro-4-methyl-1-nitrobenzene
    4. D.5-chloro-4-methyl-1-nitrobenzene
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    Answer: B

13. Q752019 · 9 Apr 2019 · Shift 1

    The increasing order of reactivity of the following compounds towards aromatic electrophilic substitution reaction is : A: ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{Cl}$, B: ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OMe}$, C: ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{Me}$, D: ${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CN}$

    1. A.A < B < C < D
    2. B.D < A < C < B
    3. C.D < B < A < C
    4. D.B < C < A < D
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    Answer: B

14. Q792019 · 8 Apr 2019 · Shift 2

    The correct statement about $\mathrm{IC}{\mathrm{l}}_5$ and $\mathrm{IC}{\mathrm{l}}_4^{-}$ is

    1. A.$\mathrm{IC}{\mathrm{l}}_5$ is square pyramidal and $\mathrm{IC}{\mathrm{l}}_4^{-}$ is square planar.
    2. B.$\mathrm{IC}{\mathrm{l}}_5$ is trigonal bipyramidal and $\mathrm{IC}{\mathrm{l}}_4^{-}$ is tetrahedral.
    3. C.$\mathrm{IC}{\mathrm{l}}_5$ is square pyramidal and $\mathrm{IC}{\mathrm{l}}_4^{-}$ is tetrahedral
    4. D.Both are isostructural.
    Show answer

    Answer: A

15. Q622019 · 12 Jan 2019 · Shift 1
    
    1. A.
    2. B.
    3. C.
    4. D.
    Show answer

    Answer: B