O1: 11 Introduction to organic chemistry

Question 1

What is a homologous series?

Answer 1

A series of compounds containing the same functional group.

Question 2

What are the characteristics of a homologous series?

Answer 2

• members share a general formula
  
  • alkanes (CnH2n+2)
  • alkenes (CnH2n)
• each member differs from the next by CH2
• length of carbon chain has little effect on chemical reactivity
• physical properties are affected
  
  • e.g. melting/boiling points and solubility
  • melting/boiling points increase by a small amount because the
    number of van der Waals forces increase
• chain branching generally reduces melting points because the
  molecules pack together less well and the van der Waals forces are
  less effective

Question 3

What is the suffix and displayed formula of an alkane?

Answer 3

-ane

Question 4

What is the suffix and displayed formula for an alkene?

Answer 4

-ene

Question 5

What are the prefix and displayed formulas of the halogenoalkanes?

Answer 5

fluoro-/ chloro-/ bromo-/ iodo-

Question 6

What is the prefix/suffix and displayed formula of an alcohol?

Answer 6

hydroxy-
-ol

Question 7

What is the suffix and displayed formula of an aldehyde?

Answer 7

-al

Question 8

What is the prefix/suffix and displayed formula of a ketone?

Answer 8

oxo-
-one

Question 9

What is the suffix and displayed formula of a carboxylic acid?

Answer 9

-oic acid

Question 10

What is the suffix and displayed formula of a nitrile?

Answer 10

-nitrile

Question 11

What is the prefix/suffix and displayed formula of an amine?

Answer 11

amino-
-amine

Question 12

What is the suffix and displayed formula of an acyl chloride?

Answer 12

-oyl chloride

Question 13

What is the suffix and displayed formula of an acid anhydride?

Answer 13

-oic anhydride

Question 14

What is the suffix and displayed formula of an ester?

Answer 14

-oate

Question 15

What is the suffix and displayed formula of an amide?

Answer 15

-amide

Question 16

What are the rules of nomenclature?

Answer 16

1. Count the longest carbon chain that contains the functional group
   
   • 1 = meth-, 2 = eth, -3 = prop-, 4 = but-, 5 = pent-, 6 = hex-
2. Name the suffix using the main functional group
3. Number the carbons in the longest chain so the functional group has the lowest possible number
   
   • if there’s more than one longest carbon chain, pick the one with the
     most side-chains
4. Write the functional group’s carbon number before the suffix
5. Any side-chains/ less important functional groups are added as prefixes in alphabetical order, with the carbon number
6. If there’s more than one identical side-chain/ functional group, use di-/tri-/tetra-, but ignore them when working out alphabetical order

Question 17

What is the prefix/ suffix and displayed formula of a cycloalkane

Answer 17

cyclo- -ane

Question 18

What is a structural isomer?

Answer 18

Molecules with the same molecular formula but different structural formulas.

Question 19

What are chain isomers?

Answer 19

Structural isomers with different arrangements of the carbon chain.

Question 20

What are position isomers?

Answer 20

Structural isomers where the functional group is attached to the main chain at different points.

Question 21

What are functional group isomers?

Answer 21

Structural isomers where there are different functional groups.

Question 22

Why does E-Z isomerism occur?

Answer 22

Because of the restricted rotation about the planar C=C double bond.

Question 23

What is a stereoisomer?

Answer 23

They have the same structural formula but different arrangements in space.

Question 24

What are the CIP (Cahn-Ingold-Prelog) rules?

Answer 24

1. Look at atomic numbers of atoms attached to C=C double bond.
2. Highest values opposite = E
3. Highest values together = Z