Organic Chemistry - 2

 

[1] Benzyne is reactive intermediate because of:

(A) It is short lived and more reactive ☑️

(B) It possess minimum potential energy

(C) It is always invisible during reaction 

(D) It possess perpendicular reactive π-bond


[2] The mechanism of nucleophilic aromatic substitution reaction based on elimination-addition is: 

(A) SN2 meachanism 

(B) Benzyne mechanism ☑️

(C) SN1 mechanism 

(D) SNAr mechanism


[3] The benzyne reactive intermediate species classified as:

(A) Aromatic ☑️

(B) Non-aromatic 

(C) Anti-aromatic 

(D) Non-benzinoid aromatic


[4] The benzyne mechanism mostly carried out in protic solvent because of:

(A) Finally it receive proton from carbanion☑️

(B) Finally it donate proton to carbanion 

(C) It helpful to produce reactive intermediate 

(D) It increased the rate of reaction


[5] Among the following most reactive bond present in benzyne reactive intermediate is:

(A) Ethylinic π-bond 

(B) Ethelinic π-bond 

(C) Benzynic π-bond 

(D) Benzylinic π-bond☑️


[6] Nucleophilic aromatic substitution (SN2) is slow reaction because of:

(A) Substrate : very weak electrophile ☑️

(B) Distortion in transition state 

(C) Repelsion between leaving group and nucleophile 

(D) Steric hindrance


[7] Ambident nucleophile meance ……

(A) Only one nucleophilic centre 

(B) Two similar nucleophilic centres

(C) Possess no nucleophilic centre 

(D) Two different nucleophilic centres☑️


[8] Von-Ritcher rearrangement is the example of :

(A) Intra-molecular rearrangement 

(B) [2,3]-Sigmatropic rearrangement 

(C) Inter-molecular rearrangement 

(D) Nucleophilic aromatic cine substitution☑️


[9] SRN1 reaction meance………….

(A) Radical nucleophilic substitution unimolecular ☑️

(B) Random nucleophilic substitution unimolecular 

(C) Racemic nucleophilic substitution unimolecular 

(D) Nucleophilic substitution reaction unimolecular


[10] Which among the following is most reactive against nucleophilic aromatic substitution ?

(A)C6H5Cl

(B)C6H5NO2☑️

(C)C6H5OCH3

(D)C6H5NH2


[11] Condensation reaction is the reverse of which of the following reaction?

(A) lock and key hypothesis 

(B) oxidation

(C) hydrolysis ☑️

(D) glycogen formation


[12] Condensation reaction always results in the formation of complex sugar (disaccharide or polysaccharide) and which of the following?

(A) amino acids 

(B) lipids 

(C) water ☑️

(D) maltose


[13] In which condensation an enol or an enolate ion reacts with a carbonyl compound to form a β-hydroxyaldehyde or β-hydroxyketone (an aldol reaction), followed by dehydration to give a conjugated enone happens?

(A) Aldol condensation ☑️

(B) Claisen reduction

(C) Henry condensation 

(D) Knoevenagel condensation


[14] Which combination of carbonyl compounds gives phenyl vinyl ketone by an aldol condensation?

Ph-co-CH=CH2

(A) Acetophenone and ketone ☑️
(B) Acetophenone and aldehyde
(C) Benzaldehyde and aldehyde 
(D) Benzaldehyde and ketone

[15] Anti Markownikoff addition with HBr/ Peroxide is not observed in _____
(A) Propene
(B) 1- Butylene
(C) 2- Butylene ☑️
(D) 1- Pentene






1 Comments

Post a Comment

Previous Post Next Post