Unit 4 - Topic 1 - Structure of Organic Compounds

Question 1

Define hydrocarbons

Answer 1

Organic compound molecules made of C and H atoms only

Question 2

Contrast between saturated hydrocarbons and unsaturated hydrocarbons

Answer 2

Saturated: Molecule only has single bonds, ie. the most H it can take

Unsatured: Contains 1 or more double or triple bonds

Question 3

What is a functional group?

Answer 3

When a hydrocarbon chain is replaced by a different atom or group of atoms - they determine physical and chemical properties of the compound

Question 4

State the naming convention & general formula for alkanes

Answer 4

Ends in “ane”
Cn H2n + 2

Question 5

State the naming convention & general formula for alkenes

Answer 5

Ends in “ene”
Cn H2n

Question 6

State the naming convention & general formula for alkynes

Answer 6

Ends in “yne”
Cn H2n - 2

Question 7

Give basic definition for structural isomers

Answer 7

Molecules that have the same molecular formula but different structural formula

Question 8

What does R stand for in functional groups?

Answer 8

Represents a carbon chain

Question 9

Give the functional group and naming convention for alcohols (is it numbered?)

Answer 9

OH group connected to carbon chain
R - OH
Ending replaced with “ol” (number if needed)

Question 10

Give the functional group and naming convention for aldehydes (is it numbered?)

Answer 10

Carbonyl group (C=O) attached to hydrogen at END of carbon chain
O
||
R - C - H
Ending replaced with “al”
(never numbered)

Question 11

Give the functional group and naming convention for ketones (is it numbered?)

Answer 11

Carbonyl group in middle/within chain
O
||
R- C - R’
Ends with “one”
(numbered)

Question 12

Give the functional group and naming convention for haloalkanes (is it numbered?)

Answer 12

Hydrogen atom replaced by halogen (F, Cl, Br, I)
H
|
R - C - X
|
H
Ends with “ane”
(numbered)

Question 13

Give the functional group and naming convention for esters (is it numbered?)

Answer 13

Carbonyl group (C=O) is attached to oxygen that’s linked to another carbon chain
O
||
R - C - O - R’
Alkyl group bonded to -O- is named first as “yl”, O=C ending in “oate”
(not numbered)

Question 14

Give the functional group and naming convention for nitriles (is it numbered?)

Answer 14

Nitrile functional group (C≡N) attached at end of carbon chain R - C ≡ N (with 2 non-bonding electrons on N atom)
Ends with “-nitrile”
(not numbered)

Question 15

Give the functional group and naming convention for amines (is it numbered?)

Answer 15

Contains an amino functional group (C - NH2)
R - NH2 (with 2 non-bonding electrons on nitrogen atom)
Ends with “-amine”
(numbered)

Question 16

Give the functional group and naming convention for amides (is it numbered?)

Answer 16

Contains a carbonyl functional group (C=O) attached to amino functional group (NH2)
O
||
R - C - NH2
Ends with “amide”
(Not numbered - it is always on end of hydrocarbon chain - made from carboxylic acid)

Question 17

Give the functional group and naming convention for carboxylic acid (is it numbered?)

Answer 17

Contains carboxyl group (COOH)
O
||
R - C - OH
Ending in “oic acid”
(not numbered)

Question 18

Define “isomers” and state the two types

Answer 18

Molecules with the same molecular formula but different structure

1. Structural isomers
2. Stereoisomers

Question 19

Define what a structural isomer is

Answer 19

A structural isomer of a compound is a molecule with the same molecular formula (number of atoms), but different structural arrangement of atoms

Question 20

Do structural isomers have different properties?

Answer 20

They can have very different chemical and physical properties

Question 21

What are the types of structural isomers? Explain them.

Answer 21

1. Chain isomers - different chain lengths and side groups (branching)
2. Positional isomers - functional group is at different position on the parent chain (parent chain remains same)

Question 22

Define what a stereoisomer is, types of stereoisomer, and when they can occur.

Answer 22

Isomers in which the atoms in two molecules are connected in the same order but different arrangements in space.
1. Geometric isomers
2. Optical isomers (irrelevant for this unit)
Only occur when each carbon atom in the double bond is attached to the two different groups (e.g H atoms, functional groups, HC chains of diff lengths)

Question 23

Do stereoisomers have different properties?

Answer 23

They possess similar physical and chemical properties

Question 24

What are the types of geometric isomers? Explain them.

Answer 24

1. Cis-isomers - the functional groups or hydrocarbon chains are on the same side