questions of the day: what is the functional group of carboxylic acids anhydrides esters amides...

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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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Questions of the day:

What is the functional group of Carboxylic Acids

Anhydrides Esters

Amides

Amines Nitro???

Today:

Unknown #2:

• Carboxylic Acids, Esters, Amides

• Amines

• (Cl, Br, nitro)

MiniQuiz

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

• 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:

What type of information do you get if your unknown

1. is soluble in water?

2. is soluble in NaOH and in NaHCO3?

3. is soluble in NaOH only, not in NaHCO3?

4. is soluble in dilute HCl solution?

5. is soluble only in conc H2SO4?

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

Carboxylic AcidsGood 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

RCO2H + NaOH        RCO2(–) Na(+)

aq.   +   H2O

1.

2.

+ HCl

Esters

Classification Test

Deep-red to purple

• Preliminary tests?

• Solubility

• Classification tests

• Derivatives

• Spectra

Compare with known ester!

a hydroxamic acid

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

Amines

Derivatives

Picrates

Benzamides: amine + benzoyl chloride

NH 2

OH

NO 2

NO 2

O 2 N

+

• Preliminary tests?

• Solubility

• Classification tests

• Derivatives

• Spectra

Carboxylic Acids

IR:

H-NMR:

• Preliminary tests?

• Solubility

• Classification tests

• Derivatives

• Spectra

OH in gas phase(non-H-bonded)

AminesIR

H-NMR

Voodoo Lily

Amorphophallus

Amides

H-NMR:

• Preliminary tests?

• Solubility

• Classification tests

• Derivatives

• SpectraIR?

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 GroupsNitro Compounds                                                                                                                                                                               

• IR

• UV

• MiniQuiz on today’s class

• Inert Compounds:

AlkanesAromatic Hydrocarbons

Alkyl halides

Next time:

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: