Carbocation

Q. When phenol is treated with $CHC{l}_3$ and $NaOH$, the product formed is:

1. Benzaldehyde
2. Salicylaldehyde
3. Salicylic acid
4. Benzoic acid

Q.

What are electron deficient compounds? Are ${\mathrm{SiCl}}_4$ and ${\mathrm{BCl}}_3$ electron-deficient species. Explain

Q. The reagent with which both acetaldehyde and acetone will react is:

1. Fehling's reagent
2. Grignard reagent
3. Tollens' reagent
4. None of this

Q. 14. Reaction with PhMgBr + (Ch3)Ch-OH gives: i)Phenol ii)Benzene iii)Ch3Ch2Ch3 iv)Ch3Ch(O-Ph)Ch3

Q. What is the correct geometry for carbocation?

1. Tetrahedral
2. Linear
3. Trigonal planar
4. Pyramidal

Q. What is the role of Grignard reagent when it react with water to give alkane?

1. act as base
2. act as acid
3. act as nucleophile
4. act as electrophile

Q. Which of the following carbocation will undergo favourable rearrangement?

1. 
2. 
3. 
4. All of the above.

Q.

Number of$s{p}^2$ hybrid carbon atoms present in Aspartame is

Q. Which of the following is/are referred as an intermediate formed in a chemical reaction?

1. Carbocation
2. Carbanion
3. Free radical
4. All of the above

Q. What is the product of the reaction when 2-bromobutane react with magnesium in presence of dry diethylether ?

1. Grignard reagent
2. Alkane
3. Alcohol
4. Ketone

Q. Which one of the following carbocation is most stable?

1. 
2. 
3. 
4. 

Q. Whath are the products of the following sequence of reaction?

1. 2-Butanol and Mg(OH)Br
2. Butanol and Mg(OH)Br
3. 2-Butanol and MgHBr
4. Butane and Mg(OH)Br

Q. Consider the following compounds:

Which of the following show hyperconjugation?

1. I only
2. II only
3. III only
4. I and III

Q. 20.4:4 Co-ordination is found in (1)ZnS (2)CuCl (3)AgI (4)All

Q. When acetone is heated with hydroxylamine, the compound formed is

1. Cyanohydrin
2. Oxime
3. Semicarbazone
4. Hydrazone

Q. In addition reactions of aldehydes, the carbonyl carbon atom changes from:

1. $s{p}^3$ to $s{p}^2$
2. $s{p}^2$ to $s{p}^3$
3. sp to $s{p}^3$
4. $s{p}^3$ to sp

Q.

Which of the following is true for carbocations?

1. It has a positive charged carbon.

2. It has a carbon atom bearing six valence electrons

3. It has a negative charge

4. It has a carbon atom bearing valence of electrons

Q.

A solution of (-) - 1 - chloro - 1 - phenylethane in toluene racemises slowly in the presence of a small amount of $SbC{l}_5$, due to the formation of:

1. carbanion

2. carbene

3. carbocation

4. free radical

Q. What is the correct geometry for carbocation?

1. Trigonal planar
2. Tetrahedral
3. Linear
4. Pyramidal

Q. Reactivity order for $S_{N}1$ is:

1. i > ii > iii > iv
2. ii > i > iii > iv
3. iii > i > ii > iv
4. iv > iii > ii > i

Q. A tertiary carbocation is more stable than the seondary carbocation because of which one of the following?

1. +I effect of $-C{H}_3$ group
2. -I effect of $-C{H}_3$ group
3. Hyperconjugation effect of $-C{H}_3$ group
4. (a) and (c) above.

Q. 2-Phenylcycloprop-2-en-1-one is allowed to react with PhMgBr and the reaction mixture is hydrolysed with perchloric acid. Find the product, giving mechanism.

Q.

Which of the typical intermediate is sp hybridised?

1. Carbanion
   

2. Free radical
   

3. Triplet carbene
   

4. Singlet carbene

Q. What is the correct geometry for carbocation?

1. Trigonal planar
2. Tetrahedral
3. Linear
4. Pyramidal

Q.

The most efficient agent for the absorption of $S{O}_3$ is

1. 

2. 

3. 

4. 

Q. The total number of contributing structures showing hyperconjugation (involving C-H bonds) for the following carbocation is

1. 3
2. 8
3. 6
4. 2

Q.

The structure and hybridization of Si $(C{H}_3{)}_4$ is:

1. bent, sp

2. trigonal, sp²

3. octahedral, sp³ d

4. tetrahedral, sp³

Q. Reactivity order for \(S_N1\)

(i) (ii) \( CH _{3}- CH _{2}- CH _{2}- Cl \) (iii) (iv)

Q. Convert Methyl Bromide to butanol

Q. The most stable carbocation is:

1. all are equal
2. $CH\equiv \stackrel{⨁}{C}$
3. $C{H}_2=\stackrel{⨁}{C}H$
4. $C{H}_3-\stackrel{⨁}{C}{H}_2$