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Questions of the day: What is the functional group of Carboxylic Acids Anhydrides Esters Amides Amines Nitro ???
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Today: Unknown #2: Carboxylic Acids, Esters, Amides Amines (Cl, Br, nitro) MiniQuiz
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Preliminary test results? Mp., bp. Which would you expect to have relatively high/relatively low mp.s / bp.s? Odor Which would you expect to have a bad smell/a pleasant smell (human perspective…) Color Which would you expect to have a color? Preliminary tests? Solubility Classification tests Derivatives Spectra Carboxylic Acids Anhydrides Esters Amides Amines Nitro
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the ratio of the velocity of light in air to the velocity of light in a given medium. sin incident angle/sin refracted angle a constant at a given temperature. an important physical property of liquids (and gases and transparent solids!) Air has a refractive index of 1.000292 at 273 K/760 mm Hg for the yellow sodium D-line at 589.3 nm. Refractive Index:
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What type of information do you get if your unknown 1. is soluble in water? 2. is soluble in NaOH and in NaHCO 3 ? 3. is soluble in NaOH only, not in NaHCO 3 ? 4. is soluble in dilute HCl solution? 5. is soluble only in conc H 2 SO 4 ? 6. is not soluble in any of the above solvents? Solubility Tests Carboxylic Acids Anhydrides Esters Amides Amines Nitro Preliminary tests Solubility? Classification tests Derivatives Spectra
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Carboxylic Acids Good mp.s (consider recrystallization) Neutralization Equivalent (titration) experimental instructions on our webpage Solubility Classification tests Derivatives (not done) Spectra Derivatives (we do not do them in the lab): Convert carboxylic acid into acid chloride first, then into amides RCO 2 H+NaOH RCO 2 (–) Na (+) aq. + H 2 O 1. 2. + HCl
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Esters Classification Test Deep-red to purple Preliminary tests? Solubility Classification tests Derivatives Spectra Compare with known ester! a hydroxamic acid
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Derivatives for Esters Hydrolyze (experimental instructions on our webpage) … to its carboxylic acid component (mp.) …. and its alcohol component alcohol derivative Preliminary tests? Solubility Classification tests Derivatives Spectra
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Amines Derivatives Picrates Benzamides: amine + benzoyl chloride NH 2 OH NO 2 2 O 2 N + Preliminary tests? Solubility Classification tests Derivatives Spectra
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Carboxylic Acids IR: H-NMR: Preliminary tests? Solubility Classification tests Derivatives Spectra OH in gas phase (non-H-bonded)
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Amines IR H-NMR Voodoo Lily Amorphophallus
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Amides H-NMR : Preliminary tests? Solubility Classification tests Derivatives Spectra IR?
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Nitro Compounds Typical properties? Classification test: Always do with a known compound to compare! Derivatives (if no other functional group available): Reduce to amine and then prepare amine derivatives Preliminary tests? Solubility Classification tests Derivatives Spectra Iron (II) Hydroxide Test for Nitro Groups Nitro Compounds
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IR UV MiniQuiz on today’s class Inert Compounds: Alkanes Aromatic Hydrocarbons Alkyl halides Next time:
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Briefly describe one test (name and result) that would allow you to distinguish between a) an aldehyde and a primary alcohol. b) an alcohol and a phenol. MiniQuiz 7 Questions:
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