Organic 2 Flashcards
(32 cards)
Q: What causes optical isomerism in molecules?
A: Chirality due to a single chiral centre leading to non-superimposable mirror images
Q: What defines a racemic mixture?
A: Equal amounts of two enantiomers resulting in no net rotation of plane-polarised light
Q: How does SN1 mechanism affect optical activity?
A: Forms racemic mixture via planar carbocation attacked equally from both sides
Q: Identify the functional group in CH3CHO
A: Aldehyde
Q: Why do aldehydes have higher solubility than ketones in water?
A: Aldehydes can form hydrogen bonds with water via their polar C=O and H atoms
Q: What observation confirms oxidation of an aldehyde with Fehling’s solution?
A: Blue Cu2+ ions form a red Cu2O precipitate
Q: What reagent reduces ketones to secondary alcohols?
A: LiAlH4 in dry ether
Q: Describe the mechanism for HCN addition to carbonyls
A: Nucleophilic addition where CN- attacks δ+ C followed by H+ bonding to O
Q: What test identifies a carbonyl group?
A: Orange precipitate with 2
Q: What product forms when ethanal reacts with iodine and alkali?
A: Yellow crystalline CHI3 (iodoform)
Q: Identify the functional group in CH3COOH
A: Carboxylic acid
Q: Why do carboxylic acids have high boiling points?
A: Hydrogen bonding between dimer molecules
Q: How is propanoic acid prepared from a nitrile?
A: Hydrolysis of propanenitrile with dilute HCl under reflux
Q: What forms when carboxylic acid reacts with PCl5?
A: Acyl chloride misty HCl fumes
Q: Name the product of ethanoic acid and ethanol with H2SO4
A: Ethyl ethanoate and water
Q: Identify the functional group in CH3COCl
A: Acyl chloride
Q: What happens when acyl chloride reacts with water?
A: Forms carboxylic acid and steamy HCl fumes
Q: What product forms when ethanoyl chloride reacts with ammonia?
A: Ethanamide and NH4Cl white smoke
Q: How is polyester formed?
A: Condensation polymerisation of diol and dicarboxylic acid releasing H2O
Q: What breaks down polyesters?
A: Hydrolysis with acid or alkali to reform monomers
Q: What intermolecular forces do aldehydes and ketones have?
A: Permanent dipole-dipole interactions due to polar C=O bonds
Q: Why do aldehydes and ketones lack intermolecular hydrogen bonds?
A: No H bonded directly to electronegative atoms like O or N
Q: What observation occurs with Tollens reagent and aldehydes?
A: Silver mirror forms on test tube
Q: What happens when LiAlH4 reacts with carboxylic acids?
A: Reduces them to primary alcohols
