Write the reaction involved in the following :
(a) Reimer-Tiemann reaction
(b) Kolbe's reaction
(c) Friedal-Crafts acylation of anisole
CBSE CLASS 12 • CHEMISTRY • CHAPTER 07
Alcohols, Phenols and Ethers
165 distinct questions across 201 board paper set appearances (2022–2026).
(A) An organic compound 'A', with molecular formula $\text{C}_2\text{H}_6\text{O}$ reacts with active metals such as sodium to give compound 'B' and hydrogen gas. 'A' on treatment with iodine and sodium hydroxide gives 'C' and in presence of $\text{H}_2\text{SO}_4$ at $413\text{ K}$ gives 'D' ($\tex...
(b) Write the reaction involved in Kolbe's reaction.
Phenol, on heating with conc. $\text{HNO}_3$, gives :
(A) o-Nitrophenol
(B) p-Nitrophenol
(C) Picric acid
(D) Sodium phenoxide
The correct order of reactivity of alcohols with Lucas reagent is :
(A) $3^\circ > 1^\circ > 2^\circ$
(B) $2^\circ > 1^\circ > 3^\circ$
(C) $1^\circ > 2^\circ > 3^\circ$
(D) $3^\circ > 2^\circ > 1^\circ$
(a) Arrange the following compounds in the decreasing order of their acidic strength :
Phenol, 4-Nitrophenol, 2,4,6-Trinitrophenol
(b) Why are alcohols more soluble in water than hydrocarbons of comparable molecular masses ?
(c) Name the reagent used in the oxidation of a primary unsaturated alcohol...
Out of the following organic compounds, the one which will react with Lucas reagent at room temperature is :
(A) $ ext{CH}_2 = ext{CH} - ext{CH}_2 ext{OH}$
(B) $ ext{CH}_3 ext{CH}_2 ext{CH}_2 ext{OH}$
(C) $ ext{C}_6 ext{H}_5 ext{CH}_2 ext{OH}$
(D) $( ext{CH}_3)_3 ext{COH}$
Write the reaction involved in the following :
(a) Reimer-Tiemann reaction
(b) Kolbe's reaction
For the pair phenol and cyclohexanol, answer the following :
(a) Why is phenol more acidic than cyclohexanol?
(b) Give one chemical test to distinguish between the two.
Choose the compound which is more acidic than phenol :
(a) o-nitrophenol
(b) ethanol
(c) o-methylphenol
(d) o-methoxyphenol
Explain why, on addition of $1\text{ mol}$ of $\text{KCl}$ to $1\text{ litre}$ of water, the boiling point of water increases, while the addition of $1\text{ mol}$ of methyl alcohol to $1\text{ litre}$ of water decreases the boiling point.
Alcohols have higher boiling points than other compounds, namely hydrocarbons, ethers and haloalkanes of comparable molecular masses. On oxidation, primary alcohols yield aldehydes with mild oxidizing agents and carboxylic acids with strong oxidizing agents. Secondary alcohols yield ketones on oxida...
Assertion (A) : p-nitrophenol is more acidic than phenol.
Reason (R) : Nitro group is an electron-withdrawing group, it stabilises phenoxide ion by dispersal of negative charge.
Alcohols undergo a number of reactions involving the cleavage of $\text{C} - \text{OH}$ bond. However, phenols do not undergo reactions involving the cleavage of $\text{C} - \text{OH}$ bond. Alcohols are weaker acids than water. Alcohols react with halogen acids to form the corresponding haloalkanes...
Assertion ($A$) : A mixture of $o$-nitrophenol and $p$-nitrophenol can be separated by steam distillation.
Reason ($R$) : $o$-nitrophenol is steam volatile due to intermolecular hydrogen bonding.
Assertion (A) : p-methoxyphenol is a stronger acid than p-nitrophenol.
Reason (R) : Methoxy group is electron-donating group whereas nitro group is electron-withdrawing.
Give reasons for the following :
(a) t-butyl bromide on reaction with sodium methoxide gives alkene as main product and not ether.
(b) o-nitrophenol is steam volatile while p-nitrophenol is not.
(c) Alcohol is less acidic than phenol.
(a) Write the reactions involved in the following : (i) Reimer-Tiemann reaction (ii) Kolbe's reaction (b) Name the reagent used in the bromination of phenol to form 2,4,6-Tribromophenol.
Williamson's synthesis of preparing dimethyl ether is a/an :
(A) electrophilic substitution
(B) $S_N1$ reaction
(C) electrophilic addition
(D) $S_N2$ reaction
(a) Account for the following : (i) Phenol is a stronger acid than an alcohol. (ii) The boiling point of alcohols decreases with increase in branching of alkyl chain. OR (b) (i) Write the mechanism of the following reaction : $\text{CH}_3\text{CH}_2\text{OH} \xrightarrow[443 \text{ K}]{\text{H}^+} \...
How do you convert the following : (Any three) (a) Phenol to picric acid (b) Propanone to 2-Methylpropan-2-ol (c) Phenol to anisole (d) Propene to Propan-1-ol
In the reaction $\text{R} - \text{OH} + \text{HCl} \xrightarrow{\text{ZnCl}_2} \text{RCl} + \text{H}_2\text{O}$, what is the correct order of reactivity of alcohol ?
(a) $1^{\circ} < 2^{\circ} < 3^{\circ}$
(b) $1^{\circ} > 3^{\circ} > 2^{\circ}$
(c) $1^{\circ} > 2^{\circ} > 3^{\circ}$
(d) $3^{\circ}...
(a) Write the mechanism of the following reaction : $\text{CH}_3 - \text{CH}_2 - \text{OH} \xrightarrow[443 \text{ K}]{\text{H}^+} \text{CH}_2 = \text{CH}_2 + \text{H}_2\text{O}$ (b) Write the equation of the reaction for the preparation of phenol from cumene.
(a) (i) Why is the C - O bond length in phenols less than that in methanol? (ii) Arrange the following in order of increasing boiling point: Ethoxyethane, Butanal, Butanol, n-butane (iii) How can phenol be prepared from anisole? Give reaction. OR (b) (i) Give mechanism of the following reaction: $\t...
Assertion (A) : Phenol gives 2,4,6-trinitrophenol on treatment with concentrated $\text{HNO}_3$ and concentrated $\text{H}_2\text{SO}_4$. Reason (R) : $-\text{OH}$ group in phenol is $\text{m-directing}$.
(d) (i) An alcohol 'A', ($\text{C}_3\text{H}_8\text{O}$) on oxidation gives compound 'B'. 'B' gives negative Tollens' test and reacts with hydrazine to give compound 'C'. 'B' reacts with $\text{NaOH}$ and $\text{I}_2$ to give yellow precipitate of 'D'. Identify 'A', 'B', 'C' and 'D'.
At low temperature, phenol reacts with dil. $\text{HNO}_3$ to yield
(A) 2, 4, 6-Trinitrophenol
(B) o-Nitrophenol only
(C) p-Nitrophenol only
(D) ortho- and para-nitrophenol
What type of deviation from Raoult’s law is shown by a mixture of phenol and aniline ? Give reason.
What will happen to the boiling point of the solution on mixing phenol and aniline ?
At low temperature, phenol on reaction with $ ext{Br}_2$ in $ ext{CS}_2$ gives
(A) $2, 4, 6$-Tribromophenol
(B) a mixture of ortho- and para-bromophenol
(C) ortho-bromophenol only
(D) para-bromophenol only
Assertion (A) : p-nitrophenol is less acidic than phenol.
Reason (R) : Nitro group is an electron-withdrawing group, which stabilises the phenoxide ion.
The boiling points of alcohols and phenols increase with increase in the number of carbon atoms due to increase in van der Waals forces. The $- ext{OH}$ group in alcohols and phenols is involved in intermolecular hydrogen bonding, due to which their boiling points are higher than those of ethers, ha...
(a) (i) Write the name of the major product(s) formed in :
(I) Reimer-Tiemann reaction
(II) Kolbe's reaction
(ii) Name the method by which aspirin is formed from salicylic acid.
(b) (i) Why does phenol undergo electrophilic substitution reaction easily ?
(b) (ii) Why is phenol more acidic than alcohol ?
(ii) Write a simple chemical test to distinguish between :
(I) Propanal and Propanone
(II) Phenol and Benzoic acid
The intermediate formed during the slowest step involved in the dehydration of alcohol is :
(A) protonated alcohol
(B) carbanion
(C) free radical
(D) carbocation
Assertion (A) : Phenol is less acidic than 4-methylphenol.
Reason (R) : The presence of an electron releasing group in phenol makes it less acidic.
For the compound having molecular formula $\text{C}_4\text{H}_9\text{Br}$, write :
(a) the isomer which is most reactive towards $\text{S}_\text{N}1$ displacement.
(b) the isomer which, on reacting with $\text{Na}$ metal in the presence of dry ether, gives $2,5$-Dimethylhexane.
(a) (i) Write the product(s) when :
(I) One $ ext{mol}$ of ethanal is treated with $1 ext{ mol}$ of $ ext{CH}_3 ext{OH}$ in the presence of dry $ ext{HCl}$ gas.
(II) Benzaldehyde is treated with conc. $ ext{NaOH}$.
(III) Ethanoic acid is heated in the presence of $ ext{P}_2 ext{O}_5$.
(ii) Write a s...
Assertion (A) : Phenol is more acidic than 4-methylphenol.\nReason (R) : The presence of an electron releasing group in phenol makes it more acidic.
Explain why, on addition of $1\text{ mol}$ of $ ext{KCl}$ to $1\text{ litre}$ of water, the boiling point of water increases, while the addition of $1\text{ mol}$ of methyl alcohol to $1\text{ litre}$ of water decreases the boiling point.
For the compound having molecular formula $ ext{C}_4 ext{H}_9 ext{Br}$, write :
(a) the isomer which is most reactive towards $ ext{S}_ ext{N}1$ displacement.
(b) the isomer which, on reacting with $ ext{Na}$ metal in the presence of dry ether, gives $2,5$-Dimethylhexane.
How will you obtain the following from benzene diazonium chloride ? Write chemical equations involved :
(a) Phenol
(b) Iodobenzene
(c) $ ext{p}$-Aminoazobenzene
(a) Name the reagents used in the following reactions :
(i) Oxidation of a primary alcohol to aldehyde
(ii) Oxidation of a primary alcohol to carboxylic acid
For the compound having molecular formula $\text{C}_4\text{H}_9\text{Br}$, write :\n(a) the isomer which is most reactive towards $\text{S}_{\text{N}}1$ displacement.\n(b) the isomer which, on reacting with Na metal in the presence of dry ether, gives $2,5$-Dimethylhexane.
(a) (i) Write the product(s) when :
(I) One mol of ethanal is treated with $1\text{ mol}$ of $\text{CH}_3\text{OH}$ in the presence of dry $\text{HCl}$ gas.
(II) Benzaldehyde is treated with conc. $\text{NaOH}$.
(III) Ethanoic acid is heated in the presence of $\text{P}_2\text{O}_5$.
(ii) Write a si...
Lucas reagent produces cloudiness immediately with :
(A) 2-methyl-1-propanol
(B) Butan-2-ol
(C) 2-methyl-2-propanol
(D) Butan-1-ol
Answer the following questions :
(b) (ii) Write the structure of the major product expected from the dinitration of 3-methylphenol.
Answer the following questions :
(c) Why is ortho-nitrophenol more acidic than ortho-methoxyphenol ?
(b) (ii) Write the structure of the major product expected from the dinitration of 3-methylphenol.
(c) Why is ortho-nitrophenol more acidic than ortho-methoxyphenol ?
Benzene diazonium chloride on reaction with phenol in weakly basic medium gives :
(A) Benzene
(B) Anisole
(C) p-hydroxyazobenzene
(D) Benzophenone
Alcohols and Phenols are acidic in nature. Electron withdrawing groups in phenol increase its acidic strength and electron releasing groups decrease it. Alcohols undergo nucleophilic substitution with hydrogen halides to yield alkyl halides. Dehydration of alcohols gives alkenes. On oxidation, prima...
OR
(b) (ii) Anisole on reaction with HI gives phenol and $\text{CH}_3 - \text{I}$ and not methanol and iodobenzene. Justify the statement.
(ii) Write the major product in the following reactions :
(I) $2 \, \text{-Cl} \xrightarrow{\text{Na/dry Ether}}$
(II) $\text{O}_2\text{N} \, \text{-CH}(\text{CH}_3)_2 + \text{Br}_2 \xrightarrow{\text{heat}}$
Assertion (A) : p-nitrophenol is more acidic than phenol.\nReason (R) : Nitro group is an electron-withdrawing group, it stabilises phenoxide ion by dispersal of negative charge.
(b) (i) Answer the following :
(I) Which isomer of $\text{C}_4\text{H}_9\text{Br}$ is most reactive towards $\text{S}_\text{N}1$ reaction ?
(II) Predict the alkene that would be formed by dehydrohalogenation of 1-Bromo-1-methylcyclohexane.
(III) Although chlorine shows strong $-\text{I}$ effect, yet...
OR
(b) (ii) Anisole on reaction with $\text{HI}$ gives phenol and $\text{CH}_3 - \text{I}$ and not methanol and iodobenzene. Justify the statement.
(ii) Write the major product in the following reactions :
(I) $2 \text{ Cl} \xrightarrow{\text{Na/dry Ether}}
(II) $\text{O}_2\text{N} \text{-} \text{CH(CH}_3)_2 + \text{Br}_2 \xrightarrow{\text{heat}}$
The products of the following reaction are :
$ ext{Benzyl phenyl ether} \xrightarrow{ ext{HI}}$
(i) $ ext{C}_6 ext{H}_5 ext{CH}_2 ext{I}$
(ii) $ ext{C}_6 ext{H}_5 ext{OH}$
(iii) $ ext{C}_6 ext{H}_5 ext{OCH}_3$
(A) (i) and (ii)
(B) (i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii) and (iii)
(a) What happens when chlorobutane is treated with $ ext{Na}$ metal in the presence of dry ether ?
(b) Arrange the following compounds in increasing order of their boiling points :
1-Bromobutane, 1-Iodobutane, Butane, 1-Chlorobutane
(a) When alkyl chlorides are treated with aqueous KOH, alcohol is formed, whereas when alkyl chlorides are treated with alcoholic KOH, alkenes are formed. Explain.
(b) Complete the given equation :
$$\text{C}_6\text{H}_5\text{Cl} + \text{CH}_3\text{COCl} \xrightarrow{\text{Anhyd. AlCl}_3}$$
The products of the following reaction are :
$\text{Benzyl phenyl ether} \xrightarrow{\text{HI}} \dots$
(i) $\text{C}_6\text{H}_5\text{CH}_2\text{I}$
(ii) $\text{C}_6\text{H}_5\text{OH}$
(iii) $\text{C}_6\text{H}_5\text{OCH}_3$
(A) (i) and (ii)
(B) (i) and (iii)
(C) (ii) and (iii)
(D) (i), (ii) and ...
Carry out the following conversions. (Attempt any 3)
I. Butan-2-one to 3-Methylpentan-3-ol
II. Anisole to 4-Methoxytoluene
III. Phenol to Benzene
IV. Chloroethane to Ethoxy ethane
The action of $\text{HNO}_2$ on methylamine gives mainly :
(A) Methyl nitrite
(B) Nitromethane
(C) Methane
(D) Methyl alcohol
Explain the following :
(a) Williamson synthesis
(b) Reimer-Tiemann reaction
How will you convert the following ?
(a) Phenol to Anisole
(b) Aniline to Phenol
(c) Propanone to Propan-2-ol
What happens when
(a) Ethanal is treated with $\text{CH}_3\text{MgBr}$ followed by hydrolysis ?
(b) Phenol is treated with Zinc dust ?
(c) Anisole is treated with $\text{HI}$ ?
In the given reaction sequence, the structure of Y would be :
$\text{(Aniline)} \xrightarrow[\text{HCl}]{\text{NaNO}_2, 0 - 5^{\circ}\text{C}} \text{X} \xrightarrow{\text{C}_2\text{H}_5\text{OH}} \text{Y}$
(A) Phenol structure
(B) Benzene structure
(C) Nitrobenzene structure
(D) Benzenediazonium chl...
Alkenes are formed by heating alcohols with $\text{conc. } \text{H}_2\text{SO}_4$. The first step in the reaction is :
(A) formation of carbocation
(B) formation of ester
(C) protonation of alcohol molecule
(D) elimination of water
(a) Can sodium ethoxide and t-butyl chloride be used for the preparation of t-butyl ethyl ether ? Give suitable explanation. Justify your answer by suggesting the appropriate starting material required for preparation of t-butyl ethyl ether.
(b) Give the IUPAC name of above mentioned ether.
Alkenes are formed by heating alcohols with conc. $ ext{H}_2 ext{SO}_4$. The first step in the reaction is :
(A) formation of carbocation
(B) formation of ester
(C) protonation of alcohol molecule
(D) elimination of water
In the given reaction sequence, the structure of Y would be :
(Aniline) $\xrightarrow[\text{HCl}, 0-5^{\circ}\text{C}]{\text{NaNO}_2}$ X $\xrightarrow{\text{C}_2\text{H}_5\text{OH}}$ Y
(A) Phenol structure
(B) Benzene structure
(C) Nitrobenzene structure
(D) Benzenediazonium chloride structure
(a) Can sodium methoxide and t-butyl bromide be used for the preparation of t-butyl methyl ether. Give suitable reason. Justify your answer by suggesting the appropriate starting material if required for the preparation of t-butyl methyl ether.
(b) Give the IUPAC name of above mentioned ether.
Alkenes are formed by heating alcohols with conc. $\text{H}_2\text{SO}_4$. The first step in the reaction is :
(A) formation of carbocation
(B) formation of ester
(C) protonation of alcohol molecule
(D) elimination of water
(a) Can sodium propoxide and t-butyl chloride be used for the preparation of t-butyl propyl ether ? Give suitable explanation. Justify your answer by suggesting the appropriate starting material required for the preparation of t-butyl propyl ether.
(b) Give the IUPAC name of the above mentioned ethe...
Explain the mechanism of acid catalysed hydration of ethene.
(a) Arrange the following compounds in the increasing order of their acidic strength :
3,5-dinitrophenol, 4-methylphenol, phenol, 2,4,6-trinitrophenol
(b) What happens when : (write equations)
(i) Phenol is distilled with $\text{Zn}$ dust ?
(ii) Anisole is treated with $\text{HBr}$ ?
Write the mechanism of dehydration of ethyl alcohol with conc. $\text{H}_2\text{SO}_4$ at $413\text{ K}$.
(a) Write the chemical equation for Williamson's synthesis.
(b) Give a method to separate $o$-nitrophenol and $p$-nitrophenol. Explain the principle involved.
Write the mechanism of dehydration of ethyl alcohol with conc. $\text{H}_2\text{SO}_4$ at $443\text{ K}$.
(a) Write the chemical equation for the following :
(i) Preparation of phenol from cumene
(ii) Nitration of anisole
Williamson synthesis of preparing unsymmetrical ether is :
(A) $ ext{S}_ ext{N}1$ reaction
(B) $ ext{S}_ ext{N}2$ reaction
(C) Electrophilic addition reaction
(D) Elimination reaction
Which one of the following amines gives an alcohol on reaction with $ ext{HNO}_2$ ?
(A) Aniline
(B) $ ext{C}_2 ext{H}_5 ext{NH}_2$
(C) $( ext{C}_2 ext{H}_5)_2 ext{NH}$
(D) $( ext{C}_2 ext{H}_5)_3 ext{N}$
Assertion (A) : Phenol is strongly acidic as compared to ethanol.
Reason (R) : Phenoxide ion is more stable than ethoxide ion.
Alcohols undergo a number of reactions involving the cleavage of $ ext{C} - ext{OH}$ bond. However, phenols do not undergo reactions involving the cleavage of $ ext{C} - ext{OH}$ bond. Alcohols are weaker acids than water. Alcohols react with halogen acids to form the corresponding haloalkanes. Ph...
Which by-product is obtained in the manufacture of phenol from cumene ?
(A) Acetaldehyde
(B) Acetone
(C) Anisole
(D) $o$-Cresol
Assertion (A) : Phenol is less acidic than alcohol.
Reason (R) : Phenoxide ion is more stable than alkoxide ion.
During dehydration of alcohol to alkene by heating with conc. $ ext{H}_2 ext{SO}_4$, the initiation step is :
(A) Formation of an ester
(B) Formation of carbocation
(C) Protonation of alcohol
(D) Elimination of water
At low temperature, phenol reacts with $ ext{Br}_2$ in $ ext{CS}_2$ to form :
(A) 2,4,6-tribromophenol
(B) $p$-bromophenol
(C) $o$-and $p$-bromophenol
(D) 2,4-dibromophenol
Phenol reacts with Bromine ($\text{Br}_2$) water to form :
(A) 2,4-dibromophenol
(B) 2-bromophenol
(C) 2,4,6-tribromophenol
(D) 4-bromophenol
Write structure of the products of the following reactions :
(a) Anisole + $ ext{HI} \longrightarrow$
(b) Phenol + conc. $ ext{HNO}_3 \longrightarrow$
(c) Cyclohexylmagnesium bromide + $ ext{HCHO} \xrightarrow{ ext{H}^+/ ext{H}_2 ext{O}} $
The reaction
\begin{center}
\text{C}_6\text{H}_5\text{-OH} + \text{NaOH (aq)} \longrightarrow \text{C}_6\text{H}_5\text{-O}^-\text{Na}^+ + \frac{1}{2}\text{H}_2\text{ (g)}
\end{center}
suggests that phenol is :
(A) Basic
(B) Neutral
(C) Acidic
(D) Amphoteric
Phenol reacts with conc. $\text{HNO}_3$ to form :
(A) Salicylic acid
(B) Picric acid
(C) Benzoic acid
(D) Phthalic acid
Assertion (A) : A mixture of $o$-nitrophenol and $p$-nitrophenol can be separated by fractional distillation.
Reason (R) : $o$-nitrophenol is steam volatile due to intramolecular hydrogen bonding.
When phenyl methyl ether is heated with $\text{HI}$, it produces :
(A) Methyl chloride and Iodobenzene
(B) Benzene and Methanol
(C) Iodobenzene and Methanol
(D) Phenol and Methyl iodide
(a) Identify 'A' to 'F' in the following reaction sequence :
[Reaction sequence diagram with reagents: $ ext{Mg} / ext{dry ether}$, $ ext{H}_2 ext{O}$, $ ext{NaOC}_2 ext{H}_5$, $ ext{alc. KOH}$, $ ext{HBr}$, $ ext{Na}$, $ ext{dry ether}$]
OR
(b) What happens when :
(i) methyl chloride is treated wi...
When phenyl methyl ether is heated with $ ext{HI}$, it produces :
(A) Methyl chloride and Iodobenzene
(B) Benzene and Methanol
(C) Iodobenzene and Methanol
(D) Phenol and Methyl iodide
Assertion (A) : p-methoxyphenol is a stronger acid than p-nitrophenol.
Reason (R) : Methoxy group shows $- ext{I}$ effect whereas nitro group shows $+ ext{I}$ effect.
Give reasons for the following :
(a) Phenol is more acidic than alcohol.
(b) t-butyl bromide on reaction with sodium ethoxide gives alkene as main product and not ether.
(c) $p$-nitrophenol is not steam volatile while $o$-nitrophenol is steam volatile.
When phenyl ethyl ether is heated with $\text{HI}$, it produces :
(A) Phenol and ethyl iodide
(B) Iodobenzene and ethanol
(C) Benzene and ethanol
(D) Ethyl chloride and iodobenzene
(ii) Cresols are less acidic than phenol.
A solution of phenol was obtained by dissolving $2 imes 10^{-2}$ kg of phenol in 1 kg of benzene. Experimentally it was found to be 73 % associated. Calculate the depression in the freezing point recorded.
OR: A solution of phenol was obtained by dissolving $2 imes 10^{-2}$ kg of phenol in 1 kg of benzene. Experimentally it was found to be 73 % associated. Calculate the depression in the freezing point recorded.
Assertion (A) : o-nitrophenol is a weaker acid than p-nitrophenol.
Reason (R) : Intramolecular hydrogen bonding makes para-isomer stronger acid than ortho-isomer.
Name the reagents used in the following reactions : (a) Bromination of phenol to 2,4,6-tribromophenol (b) Conversion of Butan-2-one to Butan-2-ol
Explain the following : (a) Reimer-Tiemann reaction (b) Kolbe's reaction (c) Williamson synthesis
(a) Predict whether the reaction is spontaneous or non-spontaneous if $E^0_{\text{cell}}$ is positive ?
Which one of the following compounds has the lowest $\text{pK}_a$ value ?
(A) $p$-Cresol
(B) $p$-Nitrophenol
(C) $m$-Nitrophenol
(D) $2,4,6$-Trinitrophenol
Assertion (A) : The boiling point of ethanol is higher than that of dimethyl ether.
Reason (R) : Ethanol molecules are associated through hydrogen bonding whereas in dimethyl ether, it is not possible.
(a) Write the equations of the reactions involved in the following : (i) Reimer-Tiemann reaction (ii) Kolbe's reaction (b) Name the reagent used in the bromination of phenol to form 2,4,6-Tribromophenol.
Which one of the following compounds has the highest $\text{pK}_a$ value ?
(A) $p$-Nitrophenol
(B) $m$-Nitrophenol
(C) $p$-Cresol
(D) 2,4,6-Trinitrophenol
Assertion (A) : The boiling point of ethanol is higher than that of dimethyl ether.
Reason (R) : Dimethyl ether molecules are associated through hydrogen bonding.
Assertion (A) : Phenol on reaction with aqueous NaOH gives sodium phenoxide. Reason (R) : This reaction supports the acidic nature of phenol.
Williamson's synthesis of preparing dimethyl ether is a/an :
(A) electrophilic substitution
(B) $\text{S}_\text{N}1$ reaction
(C) electrophilic addition
(D) $\text{S}_\text{N}2$ reaction
What happens when : (any three)
(a) $\text{Cyclohexyl-MgBr}$ is treated with $\text{CH}_3\text{CHO}$ followed by hydrolysis.
(b) Phenol is treated with conc. $(\text{HNO}_3 + \text{H}_2\text{SO}_4)$.
(c) Anisole is treated with $\text{CH}_3\text{COCl}$ in the presence of anhydrous $\text{AlCl}_3$.
(...
What happens when : (any three)
(a) $\text{CH}_3\text{MgBr}$ is treated with cyclohexanone followed by hydrolysis
(b) Phenol is treated with $\text{Br}_2$ in the presence of $\text{CS}_2$
(c) Benzene diazonium chloride is treated with $\text{H}_2\text{O}$
(d) Anisole is treated with $\text{HI}$
What happens when : (any three) (a) Cyclohexylmagnesium bromide is treated with $\text{CH}_3\text{CHO}$ followed by hydrolysis. (b) Phenol is treated with conc. $(\text{HNO}_3 + \text{H}_2\text{SO}_4)$. (c) Anisole is treated with $\text{CH}_3\text{COCl}$ in the presence of anhydrous $\text{AlCl}_3$...
Phenol is less acidic than :
(A) Ethanol
(B) o-cresol
(C) p-cresol
(D) o-nitrophenol
Write the reactions involved in the following :
(a) Reimer-Tiemann reaction
(b) Friedel-Crafts alkylation of anisole
How do you convert the following ? (a) Propan-2-ol to Propanone (b) Phenol to Benzene (c) Propene to Propan-2-ol
In the reaction R – OH + HCl $\xrightarrow{\text{ZnCl}_2}$ RCl + H$_2$O, what is the correct order of reactivity of alcohol ?
(a) 1$^{\circ}$ < 2$^{\circ}$ < 3$^{\circ}$
(b) 1$^{\circ}$ > 3$^{\circ}$ > 2$^{\circ}$
(c) 1$^{\circ}$ > 2$^{\circ}$ > 3$^{\circ}$
(d) 3$^{\circ}$ > 1$^{\circ}$ > 2$^{\circ}...
(a) Predict the products of the following reactions :
(i) $\text{CH}_3\text{CH}_2\text{OH} \xrightarrow{\text{Cu}/273 \text{K}}
(ii) \text{C}_6\text{H}_5\text{OH} \xrightarrow{\text{Br}_2(\text{aq})} $
OR
(b) Give reasons for the following :
(i) p-nitrophenol is more acidic than p-methylphenol.
(ii)...
Complete the following reactions :
(a) $\text{CH}_3\text{CH}_2\text{CH}_2\text{Br} \xrightarrow[\Delta]{\text{Alc. KOH}} \text{(A)} \xrightarrow{\text{HBr}} \text{(B)}$
(b) $\text{(A)} \xrightarrow{\text{SOCl}_2} \text{(B)} \begin{cases} \xrightarrow{\text{Na/Ether}} \text{(C)} \\ \xrightarrow{\text...
How do you convert the following : (Any three)
(a) Phenol to 2-Hydroxybenzaldehyde
(b) Anisole to 2-Methoxyacetophenone
(c) Propene to Propan-2-ol
(d) Ethanol to Ethanal
(i) Write the mechanism of the following reaction : $\text{CH}_3\text{CH}_2\text{OH} \xrightarrow[ ext{443 K}]{\text{H}^+} \text{CH}_2 = \text{CH}_2 + \text{H}_2\text{O}$ (ii) Write the equation involved in Reimer-Tiemann reaction.
Which of the following observation is shown by 2-phenyl ethanol with Lucas Reagent?
(a) Turbidity will be observed within five minutes
(b) No turbidity will be observed
(c) Turbidity will be observed immediately
(d) Turbidity will be observed at room temperature but will disappear after five minutes...
Write the name of the reaction, structure and IUPAC name of the product formed when (any 2):
(a) phenol reacts with $\text{CHCl}_3$ in the presence of NaOH followed by hydrolysis.
(b) $\text{CH}_3\text{CH}_2\text{CH}(\text{CH}_3)\text{ONa}$ reacts with $\text{C}_2\text{H}_5\text{Br}$
(c) $\text{CH}_...
Write the chemical equation involved in the following : (a) Kolbe's reaction (b) Williamson synthesis
(d) Identify A and B in the following :
$$\text{Br} \xrightarrow[\text{Dry ether}]{\text{Mg}} \text{A} \xrightarrow{\text{H}_2\text{O}} \text{B}$$
(ii) Why ortho-nitrophenol is steam volatile while para-nitrophenol is not ?
(b) What happens when
(i) Anisole is treated with $\text{CH}_3\text{Cl}$/anhydrous $\text{AlCl}_3$ ?
(ii) Phenol is oxidised with $\text{Na}_2\text{Cr}_2\text{O}_7/\text{H}^+$ ?
(iii) $(\text{CH}_3)_3 \text{C} - \text{OH}$ is heated with $\text{Cu}/573 \text{ K}$ ?
Write chemical equation in sup...
Write the chemical equation involved in the following reactions :
(a) Reimer-Tiemann reaction
(b) Acetylation of Salicylic acid
(a) (i) Write the mechanism of the following reaction :
2CH_{3}CH_{2}OH \xrightarrow[413 \text{ K}]{\text{H}^{+}} CH_{3} - CH_{2} - O - CH_{2} - CH_{3} + H_{2}O
(ii) Why ortho-nitrophenol is steam volatile while para-nitrophenol is not ?
OR
(b) What happens when
(i) Anisole is treated with CH_{3}Cl/...
The action of nitrous acid on ethylamine gives mainly : (a) ethyl nitrite (b) ethane (c) nitroethane (d) ethyl alcohol
Assertion (A) : The boiling point of ethanol is lower than that of diethyl ether. Reason (R) : In ethanol, the molecules are associated due to intermolecular hydrogen bonding, whereas in diethyl ether it is not possible.
Write the chemical equation involved in :
(a) Reimer-Tiemann reaction
(b) Williamson ether synthesis
(a) How do you convert the following : (i) Phenol to Benzene (ii) Ethanol to propan-2-ol (iii) Anisole to 2-methoxyacetophenone OR (b) (i) How will you distinguish between primary, secondary and tertiary alcohol by Lucas reagent ? (ii) Why is o-nitrophenol steam volatile while p-nitrophenol is not ?
Aspirin is obtained by the acetylation of which of the following compounds?
(a) Salicylaldehyde
(b) Salicylic acid
(c) Acetyl salicylic acid
(d) Phenol
Write the structures and IUPAC names of the products expected from the following reactions :
(a) Reaction of methanal with $(\text{CH}_3)_2\text{CHMgBr}$ followed by hydrolysis.
(b) Reaction of phenol with conc. $\text{HNO}_3$.
What happens when bromobenzene is treated with Mg in the presence of dry ether ?
Answer the following questions : (i) What happens when bromobenzene is treated with Mg in the presence of dry ether ? (ii) Which compound in each of the following pairs will react faster in $\text{S}_\text{N}^1$ reaction with $\text{OH}^-$ ? (1) $\text{CH}_2 = \text{CH} - \text{CH}_2 - \text{Cl}$ or...
Give the structures and IUPAC name of the products expected from the following reactions :
(a) Reaction of methanal with cyclohexyl-MgBr followed by hydrolysis.
(b) Reaction of phenol with $\text{Br}_2$ (aq).
When diethyl ether is heated with excess of $\text{HI}$, it produces :
(a) ethanol
(b) iodoform
(c) methyl iodide
(d) ethyl iodide
The reduction of ethanenitrile with sodium and alcohol gives : (a) 1-aminopropane (b) 1-aminoethane (c) Ethanoic acid (d) Ethanamide
(a) (i) Write hydroboration-oxidation reaction with an example. (ii) Write the products of the following reaction : A methoxybenzene molecule reacting with $\text{HBr}$. (iii) Why is p-nitrophenol more acidic than phenol ?
(b) (i) What happens when phenol reacts with (1) Conc. $\text{HNO}_3$, and (2) $\text{CHCl}_3$ in presence of aqueous $\text{NaOH}$ followed by acidification ? Write equations only. (ii) Why does the reaction of $\text{CH}_3\text{ONa}$ with $(\text{CH}_3)_3\text{C} - \text{Br}$ give 2-methylpropene ...
The action of nitrous acid on ethylamine gives mainly : (a) ethyl nitrite (b) ethyl alcohol (c) nitroethane (d) ethane
(a) (i) Write hydroboration-oxidation reaction with an example. (ii) Write the products of the following reaction : C$_6$H$_5$OCH$_3$ + HBr ⟶ (iii) Why is p-nitrophenol more acidic than phenol ? OR (b) (i) What happens when phenol reacts with (1) Conc. HNO$_3$, and (2) CHCl$_3$ in presence of aqueou...
Which of the following alkenes on acid catalysed hydration gives a tertiary alcohol ?
(a) 2-Butene
(b) 2-Methylpropene
(c) Propene
(d) 1-Butene
(a) (i) Write hydroboration-oxidation reaction with an example.
(ii) Write the products of the following reaction :
Anisole + HBr $\rightarrow$
(iii) Why is p-nitrophenol more acidic than phenol ?
OR
(b) (i) What happens when phenol reacts with
(1) Conc. $\text{HNO}_3$, and
(2) $\text{CHCl}_3$ in pr...
(a) (i) Why is the $\text{C}-\text{O}$ bond length in phenols less than that in methanol ? (ii) Arrange the following in order of increasing boiling point : Ethoxyethane, Butanal, Butanol, n-butane (iii) How can phenol be prepared from anisole ? Give reaction. OR (b) (i) Give mechanism of the follow...
Write the chemical equation for the following :
(a) Hydration of propene in presence of an acid.
(b) Reaction between Ethyl bromide and $\text{C}_2\text{H}_5\text{ONa}$.
(c) Reaction between Dimethyl ether and Hydrogen iodide.
Write the chemical equation for the following :
(a) Oxidation of secondary alcohol to ketone by chromic anhydride (CrO$_3$).
(b) Reaction of anisole with a mixture of concentrated sulphuric acid and nitric acid.
(c) Reaction of HI with 1-propoxypropane.
Assertion (A) : Phenol gives 2,4,6-trinitrophenol on treatment with concentrated $\text{HNO}_3$ and concentrated $\text{H}_2\text{SO}_4$.
Reason (R) : - OH group in phenol is $m$-directing.
Write chemical equations for the following :
(a) Reaction between phenol and Zn dust.
(b) Reaction of anisole with bromine in ethanoic acid.
(c) Reaction between methoxybenzene and $\text{HI}$.
Which of the following, on reaction with $\text{CH}_3\text{MgI}$ and subsequent hydrolysis, will form a primary alcohol?
(a) $\text{HCHO}$
(b) $\text{CH}_3\text{CHO}$
(c) $\text{CH}_3\text{COCH}_3$
(d) Benzaldehyde
Which of the following compound is called Picric acid?
(a) p-Nitrophenol
(b) 2,4-Dinitrophenol
(c) 2,4,6-Trinitrophenol
(d) 2,6-Dinitrophenol
What happens when : (a) Isopropyl chloride is treated with Na in dry ether ? (b) Ethyl chloride is treated with AgCN ?
Alcohols have higher boiling points than other classes of compounds, namely hydrocarbons, ethers and haloalkanes of comparable molecular masses. Alcohols and phenols are acidic in nature. Electron withdrawing groups in phenol increase its acidic strength and electron releasing groups decrease it. Al...
OR (b) (i) Which acid of each pair would you expect to be stronger? Give reason. (I) $\text{CH}_3\text{COOH}$ or $\text{F}-\text{CH}_2-\text{COOH}$ (II) Phenol or $\text{CH}_3 - \text{COOH}$ (ii) Distinguish between Pentan-2-one and Pentan-3-one.
Assertion (A): An ether is more volatile than an alcohol of comparable molecular mass.
Reason (R): Ethers are polar in nature.
Select the most appropriate answer from the options given below:
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true but R is not the cor...
Write the equations for the following reaction: a. Salicylic acid is treated with acetic anhydride in the presence of conc. $\text{H}_2\text{SO}_4$ b. Tert butyl chloride is treated with sodium ethoxide. c. Phenol is treated with chloroform in the presence of $\text{NaOH}$
(a) Write the reactions of ethanal with
(i) $ ext{LiAlH}_4$
(ii) dil $ ext{NaOH}$
(iii) $ ext{HCN}$
OR
(b) How will you convert the following :
(i) Ethanoic acid to 2-chloroethanoic acid
(ii) Propanone to t-butyl alcohol
(iii) $ ext{CH}_3 - ext{CH} = ext{CH} - ext{CH}_2 - ext{CN}$ to $ ext{CH}_3...