(U2) Nomenclature And Isomerism In Organic Compounds

Question 1

What is meant by a homologous series? (4)

Answer 1

Compounds which have:

• the same general formula,
• similar chemical properties,
• show a gradation in physical properties and
• successive members differ by a CH₂ unit.

Question 2

What is a functional group?

Answer 2

Reactive group within a compound

Question 3

What are structural isomers? (2)

Answer 3

Molecules which have the:

• same molecular formula
• but a different structural formula

Question 4

What are geometric isomers? (3)

Answer 4

Molecules with:

• the same structural formula,
• but different 3D arrangement of atoms
• due to the presence of one or more C=C bonds

Question 5

How do you identify Z (cis) and E (trans) isomers?

Answer 5

• Z = same side of double bond for priority groups
• E = opposite

Question 6

How are priority groups determined?

Answer 6

Based on atomic number of the bonding atom

groups like CH₃ are assigned priority based on the atomic number of Carbon

Question 7

What is the prefix for:

• alcohol
• fluorine
• chlorine
• bromine
• iodine

Answer 7

• hydroxy-
• fluoro-
• chloro-
• bromo-
• iodo-

Question 8

What is the suffix for:

• alkene
• carboxylic acid
• aldehyde
• ketone
• alcohol

Also if there are multiple functional groups, how do you name them?

Answer 8

1.
- -ene
- -oic acid
- -al
- -one
- -ol

2. an, di, tri, tetra etc.

Question 9

What are the functional groups of:

• carboxylic acids
• alcohols
• alkenes
• aldehydes
• ketones
• amines

Answer 9

• C double bond O, single bond OH (-COOH)
• -OH
• C=C
• C double bond O, single bond H (-COH)
• -C=O
• -NH₂

Question 10

What type of isomerism do cis (z)-trans (e) isomers demonstrate?

Answer 10

Geometric stereoisomerism

Question 11

What is a stereoisomer? (2)

Answer 11

• Molecules with the same structural formula
• but a different spatial arrangement of atoms