Organic Chemistry 1

Question 1

What are isomers?

Answer 1

Chemical compounds that have the same molecular formula but differ in structure (e.g. atomic connectivity or spatial orientation)

Question 2

What are structural/constitutional isomers?

Answer 2

Compounds that have the same molecular formula but differ in where and how atoms are connected to each other

Question 3

What are stereoisomers?

Answer 3

Compounds that have the same connectivity between their atoms and differ in the way their atoms are orientated

E.g. cis-trans isomers, enantiomers, disastereomers, meso compounds, conformational isomers

Question 4

What are diastereomers?

Answer 4

Stereoisomers that are not mirror images

Question 5

What are meso compounds?

Answer 5

Molecules with multiple chiral centers that have an internal plane of symmetry, not optically active

Question 6

What is generally the weaker bond (Pi or sigma)?

Answer 6

Pi bonds

Question 7

What is a primary, secondary carbon?

Answer 7

Primary carbon -> bonded to only one other carbon atom

Secondary carbon -> bonded to 2 carbons

Question 8

Do branched alkanes have higher or lower melting and boiling points?

Answer 8

Lower bc surface area reduces and LDF decrease

Question 9

What is a nucleophile?

Answer 9

Molecules attracted to positive charge, typically electron rich and negatively charged

Question 10

What is protic vs aprotic solvent?

Answer 10

Protic solvent-> solvent able to form hydrogen bonds

Aprotic solvent -> solvent cannot form hydrogen bonds

Question 11

What is the best leaving groups?

Answer 11

Weak bases that can accept a negative charge and dissociate to form a stable ion

Question 12

What are the steps of an SN1 reaction?

Answer 12

Dissociation of substrate into carbocation and leaving group followed by combination of carbocation with nucleophile to form the substituted product

Question 13

What are the steps of a free radical substitution product?

Answer 13

Initiation: Diatomic halogens are cleaved by either UV light (UV or hv) or peroxide resulting in free radicals

Propagation: free radical reacts with alkane removing hydrogen creating HX and alkyl radical which reacts with X2 to generate another radiation

Termination: 2 free radicals combine with one another to form a stable molecule

Question 14

What is a combustion reaction?

Answer 14

Alkane + O2 -> CO2 + H2O + heat

Question 15

What is pyrolysis?

Answer 15

Also called cracking, molecule is broken down by heat in the absence of oxygen

Question 16

What have higher mp and bp, internal or terminal alkenes?

Answer 16

Internal alkenes have higher mp and bp

Question 17

What are the steps of an E1 reaction?

Answer 17

The leaving group leaves producing a carbocation, then a proton is removed by a base and the double bond forms

Question 18

How do you manipulate the competition between E1 and SN1 reactions?

Answer 18

Adding heat favors E1 reaction

Question 19

What are the steps of an E2 reaction?

Answer 19

A strong base removes a proton while simultaneously a halide ion anti to the proton leaves resulting in the formation of a double bond, more substituted double bond is preferential

Question 20

How do we manipulate the competition between SN2 and E2 reactions?

Answer 20

Steric hinderance affects SN2 reactions more than E2

Strong bulky bases favor E2 over SN2 while SN2 is favored over E2 by strong nucleophiles that are weak bases

Question 21

What is catalytic hydrogenation?

Answer 21

Reductive process of adding H2 to a double bond with aid of metal catalyst (Pt, pd or Ni) and 2 hydrogens add to same face of double bond

Question 22

ADDITION REACTION TYPES

Answer 22

ON WRITTEN CUE CARDS AND IN NOTES

Question 23

What reaction conditions does polymerization need?

Answer 23

High temperature and pressure

Question 24

What has the higher BP, terminal or internal alkynes?

Answer 24

Internal alkynes boil at higher temperatures than terminal alkynes