Chapter 3

Question 1

Alkanes

Answer 1

Hydro-Carbon molecule contains only Sp3 hybridised carbon atoms (single bonds)

Might be branched/unbranched or cyclical.

General formula : CnH2+2

Fully saturated - No double or triple bonds + no functional groups.
-As a result tend to be chemically unreactive

Question 2

Root names of a compound is named according to number of carbons.

Answer 2

C1 = Meth 
C2 = Eth
C3 = Prop 
C4 = But 
C5 = Pent 

C6 = Hex 
C7 = Hept 
C8 = Oct
C9 = Non 
C10 = Dec

Question 3

Alkyl Fragments

Answer 3

Alkane minus H atoms - Suffix ‘yl’ is used

When naming a Alkane ‘ane’ is used
/
Some prefixes come from number of R groups

Question 4

Cyclic Alkanes

Answer 4

Gives it the prefix cyclo

If each corner is a carbon then that number is the suffix

C-C
|. |. Cyclobutane
C-C

6C - cyclohexane

Question 5

Alkanes - Carbon Bonds

Answer 5

Carbon atoms/molecules can be characterised by their bonds.

1) Primary Bonded - Bonded to one other atom
2) Secondary Bonded - Bonded to two other Carbons
3) Tertiary - Bonded to three other carbons
4) Quarterbary - Bonded to 4 other carbons

Question 6

Branch Chain Naming

Answer 6

Names of branch chains Alkanes by longest straight chain.

Groups attatched are numbered

They are also cited alphabetically

If it appears more than once it becomes Di - Tri

Question 7

Naming Cycloalkanes

Answer 7

1) Use the cycloalkane as the parent name - Apart from if a side chain is longer then the ring is a substituent
2) Number the substituents on the ring to arrive at lowest sum.

Question 8

Physical Properties of Alkanes

Answer 8

Room Temp & 1 Atmosphere

1-4 Carbons - They are gases
4-17 Carbons - They are Liquid
17+ Carbons - They are Solid

-More carbons means higher boiling point.

Question 9

Free Radicals

Answer 9

Highly Reactive Substance which contains an unpaired electron which is symbolised by a single dot.

2Cl•

Question 10

Free Radical

-Initiation

Answer 10

Forming of a free radical

Question 11

Free Radical

-Propogation

Answer 11

Free radicals form new free radicals via a series of reactions

Question 12

Free Radical

-Termination

Answer 12

Destroys free radicals

Ends the propagation state

Question 13

Ring Strain

Answer 13

Cyclic Alkanes are strained

This strain causes them to be unstable
- Nit often found in nature

Most are in the chain formation as this is the most stable