Dehydration of Alcohols

Q. Pure chloroform is obtained by treating (i) Ethanol with bleaching powder (ii) Acetone with bleaching powder (iii) Chloral with Sodium hydroxide (iv) CCl4 with moist Iron

Q. calculate percentage of carbon in ethanol (c2h5OH

Q. 44. The most stable carbocation amongst the following is(2) CH2 CH-CH2(3) CH3-CH2-CH2(4) CH2-C CH

Q. Why phenol react with PCL5 to give chlorobenzene as phenols do not undergo the cleavage of C-OH Bond

Q. The treatment of benzene with isobutene in the presence of sulphuric acid give (1) -butyl benzene (2) tent -butyl benzene (3) n -butyl benzene (4) No reaction

Q.

Arrange the following alcohols in the decreasing order of their ease of dehydration with H₂SO₄.

1. a > b > c > d > e

2. b > c > a > d > e

3. c > b > d > a > e

4. c > b > a > e > d

Q. Predict the pinacol-pinacolone rearrangement product of:

1. 
2. 
3. 
4. 

Q. Predict the major product in the given reaction?

1. 
2. 
3. 
4. 

Q. 21. Which of the following compound will not produce propene by reaction with HBr followed by elimination or direct only elimination reaction? 1) cyclopropane 2) propanol (CH3CH2CH2OH) 3) CH2=C=O 4) propyl bromide (CH3CH2CH2Br)

Q. The reaction of $C_2{H}_{5}OH$ with $H_{2}S{O}_4$ does not give

1. Ethylene
2. Diethyl ether
3. Acetylene
4. Ethyl hydrogen sulphate

Q. for SN1 reaction concentration pf alkyl halide and nucleophile increases by 2 times then rate of the reaction ??A.increases by 4 times B.2 times increases C. 2 times decreases D.6 times increases E.none of thes

Q. 164% Most stable carbocation is4(a) CH3- CH2(b) CH3-CH CH3(c) C(CH3)3(d) C6H5-CH2 (BHU)

Q.

Describe the effect of:

a) Addition of H₂

b) Addition of CH₃OH

c) Removal of CO

d) Removal of CH₃OH

on the equilibrium of the reaction:

Q.

Generally the Ionization enthalpy in a period increases but there are some exceptions, the one which is not an exception is

1. Be and B

2. N and O

3. Mg and Al

4. Na and Mg

Q.

The following alcohol is treated with conc. $H_{2}S{O}_4$, the major product obtained is ?

1. 
   

2. 
   

3. 
   

4. All the three will be formed in equal amounts

Q. arrange the following compounds in the increasing order of the negative inductive effect Cl CH2 CH3, CH Cl2 CH3, CCl3 CH3

Q. What is the migratory aptitude of pinnacol rearrangement and carbocation rearrangement?

Q. Explain why : Phenol is more acidic than ethanol.

Q.
The given compunds are individually heated in presence of concentrated $H_{2}S{O}_4$.
Choose the correct statement

1. Rate of dehydration is higher for compound $I$ as compared to $II$
2. Rate of dehydration is lower for compound $I$ as compared to $II$
3. Rate of dehydration is equal for compound $I$ as compared to $II$
4. None of them will react on heating in presence of concentrated $H_{2}S{O}_4$

Q.

When 3, 3-dimethyl-2-butanol is heated with $H_{2}S{O}_4$the major product obtained is

1. 2, 3-dimethyl-2-butene

2. 2, 3-dimethyl-1-butene

3. cis and trans isomers of 2, 3-dimethyl-2-butene

4. 3, 3-dimethyl-1-butene

Q. When two alkenes may be formed by dehydration of an alcohol, the alkene which is more substituted is the major or preferred product. This generalisation is known as

1. Markownikoff's rule
2. Hofmann rule
3. Saytzeff rule
4. None of these is correct

Q. Arrange the following alcohols in the decreasing order of their ease of dehydration with $H_{2}S{O}_4$

1. (iii)>(ii)>(iv)>(v)>(i)
2. (iii)>(ii)>(i)>(iv)>(v)
3. (ii)>(iii)>(iv)>(i)>(v)
4. (iii)>(ii)>(iv)>(i)>(v)

Q.

In the following reaction, X is

neo-pentyl alcohol + ^H₂^SO₄→x

1. 2-methylpent-2-ene

2. 2-methylpent-1-ene

3. 2-methylbut-2-ene

4. neopentane

Q.

The observed order of the stability of the cabocation is:

1. (CH₃)₂CH⁺ < (CH₃)₃C⁺ <CH₃⁺ < CH₃CH₂⁺

2. CH₃⁺ < CH₃CH₂⁺ <(CH₃)₂CH⁺ < (CH₃)₃C⁺

3. CH₃CH₂⁺ <(CH₃)₂CH⁺ < (CH₃)₃C⁺ < CH₃⁺

4. CH₃⁺ < CH₃CH₂⁺ < (CH₃)₃C⁺ <(CH₃)₂CH⁺

Q.

Ethylene may be obtained by dehydration of which of the following with concentrated$H_{2}S{O}_{4}at160-{170}^{0}C$

1. 

2. 

3. 

4. 

Q. Carbocation intermediate is formed in $S_{N}1$ type of reactions.

1. True
2. False

Q. In $S_{N}2$ reaction the configuration of the reactant is $R$, after the reaction the configuration of the product remains same i.e. $R$

1. True
2. False

Q. In $S_{N}2$ reaction the configuration of the reactant is $R$, after the reaction the configuration of the product remains same i.e. $R$

1. True
2. False

Q.

The sum of molar masses of the products A, B, C and D is

___

Q.
In the above reaction, the major product is shown which is formed through the intermediate (carbocation) given below:
Which bond will migrate to form the above product?

1. q
2. r
3. p
4. s