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Alcohols, Phenols and Ethers

Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.

Nomenclature and methods of preparation

Subtopic

Nomenclature and methods of preparation under Alcohols, Phenols and Ethers for Grade 12 ICSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Which of the following reagents is most suitable for the reduction of a carboxylic acid to a primary alcohol?

    A.

    NaBH4NaBH_{4}

    B.

    H2/PdH_{2}/Pd

    C.

    PCCPCC (Pyridinium chlorochromate)

    D.

    LiAlH4LiAlH_{4}

  2. 2.

    What is the IUPAC name for the simplest hydroxy derivative of benzene, commonly known as Phenol?

    A.

    Cyclohexanol

    B.

    Hydroxybenzene

    C.

    Benzenol

    D.

    Phenyl alcohol

  3. 3.

    The acid-catalyzed hydration of ethene (CH2=CH2CH_{2}=CH_{2}) produces which of the following alcohols?

    A.

    Methanol

    B.

    Ethanol

    C.

    Propan-1-ol

    D.

    Ethane-1,2-diol

Download the worksheet for Alcohols, Phenols and Ethers - Nomenclature and methods of preparation to practice offline. It includes additional chapter-level practice questions.

Physical and chemical properties

Subtopic

Physical and chemical properties under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    When phenol is treated with excess bromine water, the product obtained is:

    A.

    o-Bromophenol

    B.

    p-Bromophenol

    C.

    2,4,6-Tribromophenol

    D.

    m-Bromophenol

  2. 2.

    An unknown alcohol was treated with Lucas reagent (ZnCl2ZnCl_2 + conc. HClHCl). The observations are summarized in the flowchart below. Based on the diagram, identify the type of alcohol that reacts immediately.

    A.

    Primary alcohol

    B.

    Secondary alcohol

    C.

    Tertiary alcohol

    D.

    Dihydric alcohol

  3. 3.

    The solubility of lower alcohols in water is primarily due to:

    A.

    The formation of hydrogen bonds with water molecules

    B.

    The covalent nature of the O−HO-H bond

    C.

    The hydrophobic nature of the alkyl group

    D.

    The high boiling point of alcohols

Download the worksheet for Alcohols, Phenols and Ethers - Physical and chemical properties to practice offline. It includes additional chapter-level practice questions.

Primary, secondary and tertiary alcohols

Subtopic

Primary, secondary and tertiary alcohols under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    The vapors of a primary alcohol are passed over heated copper at 573K573 K. The main organic product formed is:

    A.

    A ketone

    B.

    An alkene

    C.

    A carboxylic acid

    D.

    An aldehyde

  2. 2.

    In the Victor Meyer's test, a primary alcohol produces a characteristic color. What is this color?

    A.

    Blue

    B.

    Blood Red

    C.

    Colorless

    D.

    Green

  3. 3.

    When a tertiary alcohol is treated with Lucas reagent (conc. HClHCl and anhydrous ZnCl2ZnCl_{2}) at room temperature, the turbidity appears:

    A.

    Immediately

    B.

    After 5 to 10 minutes

    C.

    Only upon heating

    D.

    Turbidity is not formed at all

Download the worksheet for Alcohols, Phenols and Ethers - Primary, secondary and tertiary alcohols to practice offline. It includes additional chapter-level practice questions.

Mechanism of dehydration

Subtopic

Mechanism of dehydration under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    What small molecule is eliminated as a byproduct during the conversion of CH3CH2OHCH_{3}CH_{2}OH to CH2=CH2CH_{2}=CH_{2}?

    A.

    H2H_{2}

    B.

    CO2CO_{2}

    C.

    H2OH_{2}O

    D.

    O2O_{2}

  2. 2.

    In the mechanism of dehydration of ethanol to ethene, what is the first step?

    A.

    Formation of a carbocation

    B.

    Protonation of the alcohol to form an oxonium ion

    C.

    Loss of a proton from the beta-carbon

    D.

    Nucleophilic attack of HSO4−HSO_{4}^{-} on the alcohol

  3. 3.

    The correct order of reactivity of alcohols towards acid-catalyzed dehydration is:

    A.

    1∘>2∘>3∘1^{\circ} > 2^{\circ} > 3^{\circ}

    B.

    3∘>2∘>1∘3^{\circ} > 2^{\circ} > 1^{\circ}

    C.

    2∘>1∘>3∘2^{\circ} > 1^{\circ} > 3^{\circ}

    D.

    3∘>1∘>2∘3^{\circ} > 1^{\circ} > 2^{\circ}

Download the worksheet for Alcohols, Phenols and Ethers - Mechanism of dehydration to practice offline. It includes additional chapter-level practice questions.

Acidic nature of phenol

Subtopic

Acidic nature of phenol under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    In the phenoxide ion, the negative charge is delocalized over the ortho and para positions of the benzene ring. This makes the phenoxide ion:

    A.

    Less stable than the neutral phenol molecule

    B.

    More stable than the neutral phenol molecule

    C.

    Equally stable as the ethoxide ion

    D.

    Highly reactive towards electrophilic substitution only

  2. 2.

    The presence of an electron-withdrawing group (EWG) like −NO2-\text{NO}_{2} on the benzene ring of phenol:

    A.

    Decreases the acidity by destabilizing the phenoxide ion

    B.

    Has no effect on the acidic strength

    C.

    Increases the acidity by stabilizing the phenoxide ion

    D.

    Increases the pKapK_{a} value of the phenol

  3. 3.

    Which of the following reagents can react with phenol to demonstrate its acidic nature by forming a salt?

    A.

    HClHCl

    B.

    CH3COOCH3CH_{3}COOCH_{3}

    C.

    NaOHNaOH

    D.

    NH3NH_{3}

Download the worksheet for Alcohols, Phenols and Ethers - Acidic nature of phenol to practice offline. It includes additional chapter-level practice questions.

Electrophilic substitution in phenols

Subtopic

Electrophilic substitution in phenols under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    Identify the major product obtained when phenol is treated with dilute HNO3HNO_3 at low temperature (298 K298\text{ K}):

    A.

    m-Nitrophenol

    B.

    A mixture of o-nitrophenol and p-nitrophenol

    C.

    Picric acid

    D.

    Nitrobenzene

  2. 2.

    Picric acid is chemically known as:

    A.

    2,4,6-Trinitrophenol

    B.

    2,4-Dinitrophenol

    C.

    o-Nitrophenol

    D.

    Trinitrotoluene

  3. 3.

    The −OH-OH group in phenol is:

    A.

    Deactivating and meta-directing

    B.

    Activating and ortho, para-directing

    C.

    Activating and meta-directing

    D.

    Deactivating and ortho, para-directing

Download the worksheet for Alcohols, Phenols and Ethers - Electrophilic substitution in phenols to practice offline. It includes additional chapter-level practice questions.

Preparation and properties of ethers

Subtopic

Preparation and properties of ethers under Alcohols, Phenols and Ethers for Grade 12 ICSE.

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Preview questions (no answers)

  1. 1.

    In the dehydration of ethanol using concentrated H2SO4H_{2}SO_{4}, identify 'Compound X' based on the temperature conditions shown in the diagram.

    A.

    Ethene

    B.

    Ethane

    C.

    Ethoxyethane

    D.

    Ethyl hydrogen sulfate

  2. 2.

    Ethers are soluble in water to a certain extent, similar to alcohols of comparable molecular mass. This solubility is attributed to:

    A.

    The formation of ionic bonds with water

    B.

    The ability of ether oxygen to form hydrogen bonds with water molecules

    C.

    The presence of high London dispersion forces

    D.

    The low density of ethers compared to water

  3. 3.

    Which of the following reaction conditions is used in the Williamson synthesis of diethyl ether?

    A.

    Ethanol and concentrated H2SO4H_{2}SO_{4} at 443 K443\ K

    B.

    Ethyl bromide and sodium ethoxide

    C.

    Ethanol and phosphorus pentachloride

    D.

    Ethyl bromide and aqueous KOHKOH

Download the worksheet for Alcohols, Phenols and Ethers - Preparation and properties of ethers to practice offline. It includes additional chapter-level practice questions.

Alcohols, Phenols and Ethers - Class 12 Chemistry (ICSE) | Krit.club