ch. 20 Flashcards

1
Q

What hybridization is the carbonyl carbon in carboxylic acids?

A

Sp2

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2
Q

Are carboxylic acids weaker or stronger than mineral acids?

A

weaker

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3
Q

Why do carboxylic acids dissociate more than alcohols?

A

the carboxylate ions are stablized by resonance

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4
Q

What is the pKa of carboxylic acids?

A

Approximately 5

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5
Q

What makes carboxylic acids more acidic?

A

Being substituted by EWG lowering the pKa and stabilizing the carboxylate ions.

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6
Q

What makes a carboxylic acid less acidic?

A

Being substituted by EDG raising the pKa and destabilizing the carboxylate ions.

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7
Q

Henderson-Hasselbalch Equation

A

pH = pK_a + log10([A^-] / [HA])

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8
Q

What pH causes carboxylic acids to entirely dissociate?

A

pH= 7.3; exist as carboxylate anions

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9
Q

Methods of synthesis of carboxylic acids?

A

Oxidation of alkylbenzenes, oxidation of primary alcohols/aldehydes, reaction of Grignard reagents with CO2 (carboxylation), and hydrolysis of nitriles

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10
Q

General reactions of carboxylic acids?

A

Loss of acidic proton, nucleophilic acyl substitution at the carbonyl group, substitution of the alpha carbon, and reduction.

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11
Q

Nitriles are prepared by what type of reactions?

A

SN2 reaction of alkyl halide with cyanide ion or dehydration of an amide

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12
Q

Reactions of nitriles

A

hydrolysis to carboxylic acids, reduction to primary amines, and reaction with Grignard reagents to yield ketones

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13
Q

Acids IR absorption?

A

2500-3300 cm O-H bond and 1710-1760 cm C=O

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14
Q

Nitriles IR absorption?

A

2250 cm

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15
Q

Acids CNMR and HNMR absorption?

A

165-185 and 12

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16
Q

Nitriles CNMR absoprtion

A

115-130