Reaction Methodology

Question 1

Substitution reaction for aromatic compounds

Answer 1

Hydrogen halides and water don’t react with benzene

Cl2 Br2 do not add, the substitute one of the hydrogen atoms –> preserves rings

Question 2

Friedel-Crafts Reaction

Answer 2

Benzene + alkyl chloride –> alkylated hydrocarbon + HCl
In presence of AlCl3 catalyst

Question 3

Condensation Polymers: Polyamides

Answer 3

Formed from a dicarboxylic acid and a diamine

Question 4

Condensation Polymers: Polyesters

Answer 4

Formed from a dicarboxylic acid and a diol

Question 5

Condensation polymers

Answer 5

Polyesters and polyamides

Question 6

Addition polymers

Answer 6

Polyalkenes and polydienes

Question 7

Hydrogenation (energy of delocalization of pi electrons

Answer 7

Only addition reaction that aromatic hydrocarbons can undergo

Heat from the hydrogenation of benzene is less than the predicted energy of breaking three C=C bonds (difference= energy of delocalization of electrons)

Question 8

Formation of ethers

Answer 8

Formed by condensation reactions from alcohols

Question 9

Halogenated hydrocarbons

Answer 9

F, Cl, I, Br substitute H on hydrocarbons

Question 10

Para-

Answer 10

Symmetrical/opposite of (1,4)

Question 11

Meta-

Answer 11

Skips one between (1,3)

Question 12

Ortho-

Answer 12

Next to (1,2)

Question 13

Nitration of aromatic compounds

Answer 13

Benzene + HNO3 (or HONO2) –> nitrobenzene + H2O
(H2SO4 catalyst is required)
Aromatic compounds can interact with HNO3 or HONO2 to produce nitro derivative (benzene with a NO2 group) and water

Question 14

Substitution reactions for aromatic compounds

Answer 14

benzene + Br2 –> bromobenzene + HBr (requires FeBr3 or FeCl3 catalyst)

One of the halogen atoms is substituted for a H atom, the other joins with the replaced H atom to form HX

Question 15

Oxidation of alcohols to ketones and aldehydes

Answer 15

Require catalyst – K2Cr2O7 in acidic solution
Need equivalent of one oxygen atom to convert alcohol to aldehyde or ketone, depending on where hydroxyl group is

Question 16

Preparation of carboxylic acid

Answer 16

Oxidize aldehyde to a carboxylic acid
Requires Cr2O7(2-) in acidic medium, need equivalent of one oxygen

Question 17

Hydrolysis of amides

Answer 17

Reaction with water, amides can be hydrolyzed back to parent carboxylic acid and amine (may require acid to catalyze)

Question 18

Carbonylation of methanol

Answer 18

CH3OH + CO (g) –> CH3COOH (requires Rh complex catalyst)
Used for preparation of acetic acid, not other carboxylic acids

Question 19

Saponification of esters (base hydrolysis)

Answer 19

RCOOR’ + NaOH -> RCOO-Na+ + R’OH
Reaction between an ester and a strong base (basically irreversible process)

Question 20

Formation of esters

Answer 20

Carboxylic acid + alcohol –> ester
Catalyzed by strong acid (H2SO4)
Reversible process

Question 21

Formation of carboxylic acids part 2

Answer 21

Oxidize alcohol to aldehyde then oxidize aldehyde to carboxylic acid with excess K2Cr2O7

Question 22

Addition reactions for alkenes

Answer 22

Break double (pi) bond, add halogens, hydrogens (hydrogenation), hydrogen halides, H2O

Question 23

Hydrohalogenation of alkenes/alkynes

Answer 23

Break double bond, add H or X to each C

Question 24

Hydration of alkenes/alkynes

Answer 24

Break double bond, add H or OH to each C (in acidic medium)

Question 25

pH-dependent redox potentials

Answer 25

half-rxns that don’t include OH- or H+ are pH-independent, ones that do are pH-dependent
So O2 is a stronger oxidizer in acidic medium than in basic medium