19 public questions tagged with this topic.
Ethanol (CH₃CH₂OH) is commonly used as a fuel additive (e.g., in gasoline) to improve the octane rating and reduce emissions.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Ethanol is the most commonly used solvent in pharmaceutical preparations due to its effectiveness and relatively low toxicity.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Preparation of Phenols and Ethers - Williamson and Other Methods
Phenol is more acidic due to resonance stabilization of the phenoxide ion, allowing it to form a soluble salt with NaOH, unlike ethanol, which is a weaker acid.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Physical Properties and Acidity of Alcohols and Phenols
Ethanol (CH₃CH₂OH) forms hydrogen bonds due to the -OH group, requiring more energy to break, whereas methoxymethane (CH₃OCH₃) lacks hydrogen bonding, leading to a lower boiling point.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Physical Properties and Acidity of Alcohols and Phenols
Glycerol (CH₂OH-CHOH-CH₂OH) has three -OH groups, forming extensive hydrogen bonding, which increases its boiling point compared to ethanol with one -OH group.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Classification and Nomenclature and Structures of Alcohols Phenols Ethers
Methanol (CH₃OH) has a lower molecular weight (32 g/mol) than ethanol (CH₃CH₂OH, 46 g/mol), reducing van der Waals forces and thus lowering its boiling point.
Ref: NCERT Class 12 Chemistry > Chapter 7: Alcohols, Phenols and Ethers > Topic: Chemical Reactions of Alcohols - Dehydration Oxidation Esterification
NaSH provides SH⁻ , which substitutes Br in CH₃CH₂Br via SN₂ , forming CH₃CH₂SH (ethanethiol).
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
CH₃CH₂CH₂Br reacts via SN₁ with AgNO₃ , forming AgBr (yellow precipitate) and CH₃CH₂CH₂ONO₂ .
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Classification and Nomenclature and Isomerism of Haloalkanes
Mole fraction of ethanol = 1 - 0.2 = 0.8 . Vapor pressure = 60 × 0.8 = 48 mm Hg .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Types of Solutions and Expressing Concentration
Initial moles of ethanol = (46/46) = 1 . Moles of water = (54/18) = 3 . Let additional moles of ethanol = x . New mole fraction = (1 + x/1 + x + 3) = 0.4 . 1 + x = 0.4 (4 + x) , 1 + x = 1.6 + 0.4x , 0.6x = 0.6 , x = 1 . Mass added = 1 × 46 = 46 g .
Ref: NCERT Class 12 Chemistry > Chapter 1: Solutions > Topic: Colligative Properties - Relative Lowering and Elevation of Boiling Point
Moles = 60 / 46 = 1.304 mol, heat released = 1.304 × 1366.7 = 1782.2 kJ.
Ref: NCERT Class 11 Chemistry > Chapter 5: Thermodynamics > Topic: First Law of Thermodynamics and Enthalpy and Internal Energy
Moles of H₂O = 0.5 mol; moles of C₂H₅OH = 0.5 mol. Total moles = 1. Mole fraction = 0.5.
Ref: NCERT Class 11 Chemistry > Chapter 1: Some Basic Concepts of Chemistry > Topic: Concentration Terms - Molarity Molality and Mole Fraction
