CHEM 2364 Final Exam Questions
Solved Correct.
acidity rules - Answer 1. Acidity of compounds that consist of any element BONDED TO H
increases from left to right and from top to bottom in the periodic table.
2. The acidity of CARBOXYLIC ACIDS increases with the electronegativity increases with the
electronegativity and decreases with the distance of the substituent to the carboxylic acid
group.
3. Inductive effect (shifting of electrons in a bond as result of the electronegativity of nearby
atoms)
4. Acidity increases as a result of stabilization of the conjugate base due to electron
delocalization (resonance).
order of acidity - Answer H3O+ > ArNH3+ > RCO2H > H2CO3 > ArOH > R2NH+ > H2O > ROH
basicity rules - Answer As acidity increases, basicity decreases.
order of basicity - Answer RO- > HO- > R3N > ArO- > HCO3- > RCO2- > ArNH2 > H2O
alkyl halide test - Answer a) AgNO3/EtOH (SN1)
b) NaI/Acetone (SN2)
AgNO3/EtOH - Answer - 2 step mechanism
- Carbocation formation (benzylic/allylic > 3 > 2)
- Stereochemistry: If starting with a chiral compound, the final product will be a racemic
mixture.
NaI/Acetone - Answer - 1 step (concerted) mechanism
- Inversion of configuration (backside attack)
- Causes a change in stereochemistry if the starting material and product are chiral
- Order of reactivity: Methyl > 1 > 2
alcohol test - Answer a) Lucas Test (HCl/ZnCl2)
b) Jones Oxidation (CrO3/H2SO4)
Lucas Test - Answer - SN1 mechanism without catalyst
, - Converts alcohol to alkyl chloride
- PHENOLS DO NOT REACT
- Order of reactivity: 3 > 2 > 1
- Caution: HCl is a corrosive poison.
Jones Oxidation - Answer - Oxidizes primary alcohols to carboxylic acids; oxidizes secondary
alcohols to ketones
- NO TERTIARY ALCOHOLS
- Cautions: H2SO4 is a corrosive poison; Cr(VI) compounds are carcinogenic
alkene test - Answer Bromination (Br2/CH2Cl2 - aka DCM)
bromination - Answer - Electrophilic addition at the double bond
- Stereochemistry: Anti- addition (Zaitsev); more substituted bonds are more stable
- Note: Anilines also react with Br2/DCM the same way as phenols.
- Caution: Bromine is a corrosive poison.
aldehyde test - Answer a) Tollen's test
b) 2,4-DNP
c) Jones
Tollen's test (aldehydes) - Answer - Aldehydes are oxidized to their corresponding carboxylic
acids
- Caution: Tollen's reagent is explosive! (Flush down the sink with copious amounts of water
after using)
2,4-DNP (aldehydes + ketones) - Answer - Addition, followed by elimination
- Does NOT react with esters, amides, or carboxylic acids
- Caution: 2,4-DNP is a suspected carcinogen; also corrosive (prepared with sulfuric acid)
phenol test - Answer a) FeCl3
b) Br2/DCM (regioselectivity!)
c) Jones
FeCl3 test - Answer - Forms enols
- Aldehydes/ketones WITH an a-hydrogen (undergo tautomerization)
Solved Correct.
acidity rules - Answer 1. Acidity of compounds that consist of any element BONDED TO H
increases from left to right and from top to bottom in the periodic table.
2. The acidity of CARBOXYLIC ACIDS increases with the electronegativity increases with the
electronegativity and decreases with the distance of the substituent to the carboxylic acid
group.
3. Inductive effect (shifting of electrons in a bond as result of the electronegativity of nearby
atoms)
4. Acidity increases as a result of stabilization of the conjugate base due to electron
delocalization (resonance).
order of acidity - Answer H3O+ > ArNH3+ > RCO2H > H2CO3 > ArOH > R2NH+ > H2O > ROH
basicity rules - Answer As acidity increases, basicity decreases.
order of basicity - Answer RO- > HO- > R3N > ArO- > HCO3- > RCO2- > ArNH2 > H2O
alkyl halide test - Answer a) AgNO3/EtOH (SN1)
b) NaI/Acetone (SN2)
AgNO3/EtOH - Answer - 2 step mechanism
- Carbocation formation (benzylic/allylic > 3 > 2)
- Stereochemistry: If starting with a chiral compound, the final product will be a racemic
mixture.
NaI/Acetone - Answer - 1 step (concerted) mechanism
- Inversion of configuration (backside attack)
- Causes a change in stereochemistry if the starting material and product are chiral
- Order of reactivity: Methyl > 1 > 2
alcohol test - Answer a) Lucas Test (HCl/ZnCl2)
b) Jones Oxidation (CrO3/H2SO4)
Lucas Test - Answer - SN1 mechanism without catalyst
, - Converts alcohol to alkyl chloride
- PHENOLS DO NOT REACT
- Order of reactivity: 3 > 2 > 1
- Caution: HCl is a corrosive poison.
Jones Oxidation - Answer - Oxidizes primary alcohols to carboxylic acids; oxidizes secondary
alcohols to ketones
- NO TERTIARY ALCOHOLS
- Cautions: H2SO4 is a corrosive poison; Cr(VI) compounds are carcinogenic
alkene test - Answer Bromination (Br2/CH2Cl2 - aka DCM)
bromination - Answer - Electrophilic addition at the double bond
- Stereochemistry: Anti- addition (Zaitsev); more substituted bonds are more stable
- Note: Anilines also react with Br2/DCM the same way as phenols.
- Caution: Bromine is a corrosive poison.
aldehyde test - Answer a) Tollen's test
b) 2,4-DNP
c) Jones
Tollen's test (aldehydes) - Answer - Aldehydes are oxidized to their corresponding carboxylic
acids
- Caution: Tollen's reagent is explosive! (Flush down the sink with copious amounts of water
after using)
2,4-DNP (aldehydes + ketones) - Answer - Addition, followed by elimination
- Does NOT react with esters, amides, or carboxylic acids
- Caution: 2,4-DNP is a suspected carcinogen; also corrosive (prepared with sulfuric acid)
phenol test - Answer a) FeCl3
b) Br2/DCM (regioselectivity!)
c) Jones
FeCl3 test - Answer - Forms enols
- Aldehydes/ketones WITH an a-hydrogen (undergo tautomerization)
