Aldehydes, Ketones & Acids · JEE Main previous year questions

For the reaction $${\text{RCH}}_2\text{Br}+{\text{I}}^{-}\stackrel{\text{Acetone}}{\to }{\text{RCH}}_2\text{I}+{\text{Br}}^{-}\text{major}$$ The correct statement is

1. A.The solvent used in the reaction solvates the ions formed in rate determining step.
2. B.${\text{Br}}^{-}$ can act as competing nucleophile.
3. C.The reaction can occur in acetic acid also.
4. D.The transition state formed in the above reaction is less polar than the localised anion.

Match List I with List II | LIST I (Name of reaction) | LIST II (Reagent used) | | :--- | :--- | | A. Hell-Volhard-Zelinsky reaction | I. $NaOH+I_2$ | | B. Iodoform reaction | II. (i) $Cr{O}_{2}C{l}_2,C{S}_2$ (ii) $H_{2}O$ | | C. Etard reaction | III. (i) $B{r}_2$ / red phosphorus (ii) $H_{2}O$ | | D. Gatterman-Koch reaction | IV. $CO,HCl$, anhyd. $AlC{l}_3$ | Choose the correct answer from the options given below:

1. A.A-III, B-I, C-IV, D-II
2. B.A-III, B-I, C-II, D-IV
3. C.A-I, B-II, C-III, D-IV
4. D.A-III, B-II, C-I, D-IV

Reaction of propanamide with $\mathrm{B}{\mathrm{r}}_2/KOH(\mathrm{aq})$ produces :

1. A.Propanenitrile
2. B.Propylamine
3. C.Ethylnitrile
4. D.Ethylamine

1. A.Both Statement I and Statement II are true
2. B.Statement I is false but Statement II is true
3. C.Statement I is true but Statement II is false
4. D.Both Statement I and Statement II are false

1. A.(A) – (IV), (B) – (III), (C) – (II), (D) – (I)
2. B.(A) – (I), (B) – (II), (C) – (III), (D) – (IV)
3. C.(A) – (II), (B) – (III), (C) – (IV), (D) – (I)
4. D.(A) – (III), (B) – (II), (C) – (I), (D) – (IV)

1. A.
2. B.
3. C.
4. D.

'A' and 'B' respectively are: $\mathrm{A}\underset{\text{(2) }\mathrm{Zn}-{\mathrm{H}}_2\mathrm{O}}{\overset{\text{(1) }{\mathrm{O}}_3}{\to }}\text{Ethane-1,2-dicarbaldehyde}+\text{Glyoxal/Oxaldehyde}$ $\mathrm{B}\underset{\text{(2) }\mathrm{Zn}-{\mathrm{H}}_2\mathrm{O}}{\overset{\text{(1) }{\mathrm{O}}_3}{\to }}\text{5-oxohexanal}$

1. A.1-methylcyclohex-1,3-diene & cyclopentene.
2. B.Cyclohex-1,3-diene & cyclopentene
3. C.1-methylcyclohex-1,4-diene & 1-methylcyclopent-1-ene
4. D.Cyclohex-1,3-diene & 1-methylcyclopent-1-ene

1. A.(B) and (C)
2. B.(C) and (D)
3. C.(A) and (D)
4. D.(A) and (C)

Given below are two statements : Statement I : In Hofmann degradation reaction, the migration of only an alkyl group takes place from carbonyl carbon of the amide to the nitrogen atom. Statement II : The group is migrated in Hofmann degradation reaction to electron deficient atom. In the light of the above statements, choose the most appropriate answer from the options given below :

1. A.Both Statement I and Statement II are correct.
2. B.Both Statement I and Statement II are incorrect.
3. C.Statement I is correct but Statement II is incorrect.
4. D.Statement I is incorrect but Statement II is correct.

Decarboxylation of all six possible forms of diaminobenzoic acids ${\text{C}}_6{\text{H}}_3({\text{NH}}_2{)}_2\text{COOH}$ yields three products A, B and C. Three acids give a product 'A', two acids gives a product 'B' and one acid give a product 'C'. The melting point of product 'C' is

1. A.$63^{\circ }\text{C}$
2. B.$90^{\circ }\text{C}$
3. C.$104^{\circ }\text{C}$
4. D.$142^{\circ }\text{C}$

The reagent, from the following, which converts benzoic acid to benzaldehyde in one step is $${\mathrm{C}}_6{\mathrm{H}}_5\mathrm{COOH}⟶{\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CHO}$$

1. A.$\mathrm{LiAl}{\mathrm{H}}_4$
2. B.$\mathrm{KMn}{\mathrm{O}}_4$
3. C.$\mathrm{MnO}$
4. D.$\mathrm{NaB}{\mathrm{H}}_4$

A biodegradable polyamide can be made from :

1. A.Glycine and isoprene
2. B.Hexamethylene diamine and adipic acid
3. C.Glycine and aminocaproic acid
4. D.Styrene and caproic acid

1. A.(I), (III) and (IV) only
2. B.Only (IV)
3. C.Only (II)
4. D.(III) and (IV) only

In the reaction of hypobromite with amide, the carbonyl carbon is lost as :

1. A.$\mathrm{C}{\mathrm{O}}_2$
2. B.$\mathrm{CO}$
3. C.$\mathrm{HC}{\mathrm{O}}_3^{-}$
4. D.$\mathrm{C}{\mathrm{O}}_3^{2-}$

In Tollen's test for aldehyde, the overall number of electron(s) transferred to the Tollen's reagent formula $[\mathrm{Ag}(\mathrm{N}{\mathrm{H}}_3{)}_2{]}^{+}$ per aldehyde group to form silver mirror is ____. (Round off to the Nearest Integer).

The increasing order of the reactivity of the following compounds in nucleophilic addition reaction is : Propanal, Benzaldehyde, Propanone, Butanone

1. A.Butanone < Propanone < Benzaldehyde < Propanal
2. B.Benzaldehyde < Butanone < Propanone < Propanal
3. C.Propanal < Propanone < Butanone < Benzaldehyde
4. D.Benzaldehyde < Propanal < Propanone < Butanone

1. A.
2. B.
3. C.
4. D.

At $35^{\circ }\mathrm{C}$, the vapour pressure of $\mathrm{C}{\mathrm{S}}_2$ is $512\mathrm{mm}\mathrm{Hg}$ and that of acetone is $344\mathrm{mm}\mathrm{Hg}$. A solution of $\mathrm{C}{\mathrm{S}}_2$ in acetone has a total vapour pressure of $600\mathrm{mm}\mathrm{Hg}$. The false statement amongst the following is :

1. A.$\mathrm{C}{\mathrm{S}}_2$ and acetone are less attracted to each other than to themselves.
2. B.a mixture of $100\mathrm{ml}$. $\mathrm{C}{\mathrm{S}}_2$ and $100\mathrm{ml}$. acetone has a volume $<200\mathrm{ml}$.
3. C.Heat must be absorbed in order to produce the solution at $35^{\circ }\mathrm{C}$
4. D.Raoult's law is not obeyed by this system.

1. A.
2. B.
3. C.
4. D.

1. A.
2. B.
3. C.
4. D.

The vapour pressure of acetone at $20^{\circ }\mathrm{C}$ is $185\mathrm{torr}$. When $1.2\mathrm{g}$ of a non-volatile substance was dissolved in $100\mathrm{g}$ of acetone at $20^{\circ }\mathrm{C}$, its vapour pressure was $183\mathrm{torr}$. The molar mass ($\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$) of the substance is:

1. A.64
2. B.128
3. C.488
4. D.32

3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is:

1. A.36 mg
2. B.42 mg
3. C.54 mg
4. D.18 mg

Tollen's reagent and Fehling solutions are used to distinguish between

1. A.acids and alcohols
2. B.alkanes and alcohols
3. C.ketones and aldehydes
4. D.n-alkanes and branched alkanes