Alcohols, Phenols and Ethers

CBSE Class 12 Chemistry · every board question from this chapter, 2023–2026 · 1 of them repeated across years

• Lucas reagent produces cloudiness immediately with:2026
• Dehydration of tertiary alcohols with Cu at 573 K gives:2026
• The intermediate formed during the slowest step involved in the dehydration of alcohol is:2026
• Williamson synthesis is an example of:2026
• The dehydration of 1°, 2° and 3° alcohols follows the order:2026
• Aspirin is obtained by acetylation of2026
• At low temperature, phenol on reaction with Br_2 in CS_2 gives2026
• (CH_3)_3 C-OC_2 H_5 on reaction with HI gives2026
• At low temperature, phenol reacts with dil. HNO_3 to yield2026
• Identify the correct increasing order of boiling points of the given compounds:2026
• Primary, secondary and tertiary alcohols can be distinguished by:2026
• Assertion: Alcohols act as Bronsted bases as well as Bronsted acids. Reason (R): Alcohols react as both nucleophiles and…2026
• Assertion: The presence of -OH group in phenols directs the incoming group to ortho and para positions. Reason (R): -OH group in…2026
• Assertion: The presence of -OH group in phenols directs the incoming group at ortho- and para- positions. Reason (R): -OH group…2026
• Assertion: Alcohols act as Bronsted bases as well as Bronsted acids. Reason (R): It is due to the presence of unshared electron…2026
• Assertion (A):(CH_3)_3 C-O-CH_3 gives (CH_3)_3 C-I and CH_3 OH on reaction with HI. Reason (R): The reaction occurs by S_N 1…2026
• Assertion: Ethers have lower boiling points than the boiling points of alcohols. Reason (R): This is due to the presence of…2026
• Assertion: Phenol is more acidic than 4-methylphenol. Reason (R): The presence of an electron releasing group in phenol makes it…2026
• Assertion: The presence of -OH group in phenols directs the incoming group to meta position in the ring. Reason (R): -OH group in…2026
• Assertion: Phenol is less acidic than 4-methylphenol. Reason (R): The presence of an electron releasing group in phenol makes it…2026
• Assertion: p-nitrophenol is more acidic than phenol. Reason (R): Nitro group is an electron-withdrawing group, it stabilises…2026
• Write the reaction involved in the following: Reimer-Tiemann reaction Kolbe's reaction Friedal-Crafts acylation of anisole2026
• Ethers are prepared by the dehydration of alcohols in presence of protic acids at 413 K. Symmetrical and unsymmetrical ethers can…2026
• Alcohols and Phenols are acidic in nature. Electron withdrawing groups in phenol increase its acidic strength and electron…2026
• Alcohols have higher boiling points than other compounds, namely hydrocarbons, ethers and haloalkanes of comparable molecular…2026
• An organic compound 'A', with molecular formula C_2 H_6 O reacts with active metals such as sodium to give compound 'B' and…2026
• Which by-product is obtained in the manufacture of phenol from cumene?2025
• During dehydration of alcohol to alkene by heating with conc. H_2 SO_4, the initiation step is:2025
• Williamson synthesis of preparing unsymmetrical ether is:2025
• CH_3 CH_2 OH can be converted to CH_3 CHO by:2025
• What will be formed after oxidation reaction of secondary alcohol with chromic anhydride (CrO_3)?2025
• The reaction R-OH+Na → RO^- Na^++1/2 H_2( g) suggests that alcohols are:2025
• The reaction suggests that phenol is:2025
• Which is the correct order of acid strength from the following?2025
• In the reaction R-OH+HCl →ZnCl_2 RCl+H_2 O, what is the correct order of reactivity of alcohols?2025asked 2×
• Phenol reacts with conc. HNO_3 to form:2025
• The conversion of phenol to salicylic acid can be accomplished by2025
• Phenol reacts with Bromine (Br_2) water to form:2025
• At low temperature, phenol reacts with Br_2 in CS_2 to form:2025
• Alkenes are formed by heating alcohols with conc. H_2 SO_4. The first step in the reaction is:2025
• Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by steam distillation. Reason(R): o -nitrophenol is…2025
• Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by steam distillation. Reason(R): o -nitrophenol is…2025
• Assertion: A mixture of o -nitrophenol and p -nitrophenol can be separated by fractional distillation. Reason(R): o -nitrophenol…2025
• Assertion: The boiling point of ethanol is higher than that of methoxymethane. Reason (R): There is intramolecular hydrogen…2025
• Assertion: Phenol is less acidic than alcohol. Reason (R): Phenoxide ion is more stable than alkoxide ion.2025
• Assertion: The bond angle C - O - C in ethers is slightly greater than tetrahedral angle. Reason (R): This is because of the…2025
• Assertion: Phenol is strongly acidic as compared to ethanol. Reason (R): Phenoxide ion is more stable than ethoxide ion.2025
• Write the mechanism of dehydration of ethyl alcohol with conc. H_2 SO_4 at 443 K.2025
• Write the mechanism of dehydration of ethyl alcohol with conc. H_2 SO_4 at 413 K.2025
• Explain the mechanism of acid catalysed hydration of ethene.2025
• Can sodium methoxide and t-butyl bromide be used for the preparation of t-butyl methyl ether. Give suitable reason. Justify your…2025
• Write the chemical equation for Williamson's synthesis. Give a method to separate o -nitrophenol and p -nitrophenol. Explain the…2025
• Write the chemical equation for the following: (i) Preparation of phenol from cumene (ii) Nitration of anisole Complete the…2025
• Arrange the following compounds in the increasing order of their acidic strength: 3,5-dinitrophenol, 4-methylphenol, phenol,…2025
• Can sodium propoxide and t-butyl chloride be used for the preparation of t-butyl propyl ether? Give suitable explanation. Justify…2025
• Can sodium ethoxide and t-butyl chloride be used for the preparation of t-butyl ethyl ether? Give suitable explanation. Justify…2025
• Phenols undergo electrophilic substitution reactions readily due to the strong activating effect of OH group attached to the…2025
• Alcohols undergo a number of reactions involving the cleavage of C - OH bond. However, phenols do not undergo reactions involving…2025
• An organic compound 'A', molecular formula C_2 H_6 O oxidises with CrO_3 to form a compound 'B'. Compound 'B' on warming with…2025
• Consider the following reaction: Identify A and B from the given options:2024
• Out of the following alkenes, the one which will produce tertiary butyl alcohol on acid catalysed hydration is2024
• Consider the following reaction: The major product of the reaction is:2024
• Consider the following reaction: The major product obtained is:2024
• Consider the following reaction: The major product obtained is:2024
• Which of the following is most acidic?2024
• Phenol is less acidic than:2024
• Which one of the following compounds has the highest pK_a value?2024
• (CH_3)_3 C-O-CH_3 reacts with HI to give:2024
• CH_3-O-CH_3 when treated with excess HI gives:2024
• (CH_3)_2 CH-O-CH_3 when treated with HI gives:2024
• (CH_3)_2 CH-O-CH_3 reacts with HI to give:2024
• Anisole reacts with HI to give:2024
• C_6 H_5-O-CH_3 when treated with HI gives:2024
• Ethanol on heating with conc. H_2 SO_4 at 413 K gives:2024
• Aspirin is formed by the acetylation of:2024
• A compound (X) with the molecular formula C_3 H_8 O can be oxidized by strong oxidizing agents to another compound (Y) whose…2024
• Visha took 4 text-tubes namely A, B, C & D containing CH_3 CH=CH_2, CH_3 CH_2 CH=CH_2, CH_3 CH=CH-CH_3 and (CH_3)_2 C=CH_2…2024
• Dehydration of tertiary alcohols with Cu at 573 K gives:2024
• Which of the following has the highest boiling point?2024
• The reaction of an alkyl halide with sodium alkoxide forming ether is known as:2024
• Phenol does not undergo nucleophilic substitution reaction easily due to:2024
• Match the reagents required for the given reactions: I. Oxidation of primary alcohols to (p) NaBH_4 aldehydes II. Butan-2-one to…2024
• The suitable Grignard reagent used for the synthesis of CH_3-CH-CH_2-OH with methanal is:2024
• The correct order of the ease of dehydration of the following alcohols by the action of conc. H_2 SO_4 is:2024
• Phenol on reaction with aqueous bromine at room temperature gives:2024
• Assertion: p-nitrophenol is less acidic than phenol. Reason (R): Nitro group is electron withdrawing and helps in the…2024
• Assertion: Phenols are stronger acids than alcohols. Reason (R): Alkoxide ion is more stable than phenoxide ion.2024
• Assertion: Bromination of Phenol can be carried out even in the absence of Lewis acid. Reason (R): - OH group of Phenol has the…2024
• Assertion: Phenol on reaction with aqueous NaOH gives sodium phenoxide. Reason (R): This reaction supports the acidic nature of…2024
• Assertion: The boiling point of ethanol is higher than that of dimethyl ether. Reason (R): Dimethyl ether molecules are…2024
• Assertion: p-methoxyphenol is a stronger acid than m-methoxy phenol. Reason (R): Methoxy group exerts +R effect at both ortho and…2024
• Assertion (A): The boiling point of ethanol is higher than that of dimethyl ether. Reason (R): Ethanol molecules are associated…2024
• Assertion: p-methoxyphenol is a stronger acid than p-nitrophenol. Reason (R): Methoxy group shows +I effect whereas nitro group…2024
• Give the structure of the major product expected from the following reactions: 1 × 3 Reaction of Ethanal with methyl-magnesium…2024
• Give the equations of reactions for the preparation of: (any three) Phenol from chlorobenzene Salicylaldehyde from phenol…2024
• Write the equations of the reactions involved in the following: (i) Reimer-Tiemann reaction (ii) Kolbe's reaction Name the…2024
• Write the mechanism of the following reaction: CH_3 CH_2 OH →[443 K]H^+ CH_2=CH_2 Write the main product in each of the following…2024
• Give the structure of the major product expected from the following reactions: 1 × 3 Reaction of propanal with methyl magnesium…2024
• Write chemical equations for the following reactions: (Do any three) Hydroboration - oxidation reaction Williamson Synthesis…2024
• Sodium phenoxide when heated with CO_2 under pressure, followed by acidification, yields:2023
• Which of the following alcohols will not undergo oxidation?2023
• Aspirin is obtained by the acetylation of which of the following compounds?2023
• For the conversion of propene into 1-propanol, which of the following reagents and conditions should be used?2023
• Which of the following alkenes on acid catalysed hydration gives a tertiary alcohol?2023
• When diethyl ether is heated with excess of HI, it produces:2023
• Show how you will synthesise: from a suitable alkene. from methanal using a suitable Grignard reagent.2023
• Write the mechanism of the following reaction: CH_2=CH_2+H_2 O →H^+ CH_3 CH_2 OH2023
• Write the chemical equation involved in the following reactions: 2 × 1 Reimer-Tiemann reaction Acetylation of Salicylic acid2023
• Account for the following: (i) Phenol is a stronger acid than an alcohol. (ii) The boiling point of alcohols decreases with…2023
• For the pair phenol and cyclohexanol, answer the following: Why is phenol more acidic than cyclohexanol? Give one chemical test…2023
• Predict the products of the following reactions: (i) CH_3 CH_2 OH →Cu / 273 K (ii) C_6 H_5 OH →Br_2(aq) OR Give reasons for the…2023
• Which of the following is an appropriate set of reactants for the preparation of 1-methoxy-4-nitrobenzene and why?2023
• Write the chemical equation involved in the following: 2 × 1 Kolbe's reaction Williamson synthesis2023
• Write the mechanism of acid dehydration of ethanol to yield ethene.2023
• Write the mechanism of the following reaction: CH_2=CH_2+H_2 O →H^+ CH_3 CH_2 OH Write the structures of the products obtained by…2023
• Write the mechanism of the following reaction: CH_3-CH_2-OH 443 K^+H^+ CH_2=CH_2+H_2 O Write the equation of the reaction for the…2023
• (i) Write hydroboration-oxidation reaction with an example. (ii) Write the products of the following reaction: (iii) Why is…2023
• (i) Write the mechanism of the following reaction: 2+1 2 CH_3 CH_2 OH →[413 K]H^+ CH_3-CH_2-O-CH_2-CH_3+H_2 O (ii) Why…2023
• How do you convert the following: (Any three) Phenol to 2-Hydroxybenzaldehyde Anisole to 2-Methoxyacetophenone Propene to…2023
• How do you convert the following: (Any three) Phenol to picric acid Propanone to 2-Methylpropan-2-ol Phenol to anisole Propene to…2023
• (i) Why is the C-O bond length in phenols less than that in methanol? (ii) Arrange the following in order of increasing boiling…2023

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