1. Section 6
Hydrocarbons

2. What are Hydrocarbons?
A hydrocarbon is a molecule which contains only the elements Carbon and Hydrogen.
Hydrocarbons are obtained from the Fractional Distillation of crude oil.
We use them for fuels in cars (octane) and in cookers (methane).

3. How Do We Group All These Hydrocarbons Together?

4. Hydrocarbons Homologous Series Alkanes Alkenes Cycloalkanes
a group of chemically similar compounds which can be represented by a general formula.
Physical properties change gradually through the series
Alkanes
Alkenes
Cycloalkanes

5. Cycloalkanes X Monsters X Eat Cyclopropane Pupils Cyclobutane But
Cyclopentane Prefer
Cyclohexane Hairy
Cycloheptane Haggis
Cyclooctane Or
Cyclononane Nice
Cyclodecane Dinners

6. Cycloalkanes - Cyclopropane
3D Full Structural  2D Full Formula Structural
Formula
Get them to make a model of methane to show that it doesn’t sit flat on the table but does in fact have a 3D shape. Also C = 4 bonds and H = 1

7. Cycloalkanes Each member can be represented in three different ways:
Cyclopropane
Full Structural
Formula
Shortened Structural
Molecular Formula

8. Cycloalkanes
The Cycloalkanes are a family of hydrocarbons and all share the same chemical properties:
Single Carbon to carbon bonds
( - C – C - )
All end in -‘ane’
Saturated hydrocarbons
All share a General Formula
Instead of forming straight chain molecules they form circular or cyclical molecules.
Burn to produce carbon dioxide and water

9. Physical Properties They increase in size
The m.p/b.p increases as the size increases
Uses
Cyclohexane for making nylon
Solvents for compounds that don’t dissolve in water

10. Shortened Structural Formula Full Structural Formula
Cycloalkanes
Cycloalkane
(Carbon Atoms)
Molecular Formula
Shortened Structural Formula
Full Structural Formula
Cyclopropane
(3)
C3H6
CH2CH2CH2
Cyclobutane
(4)
Cyclopentane
(5)
C5H10

11. Shortened Structural Formula Full Structural Formula
Cycloalkanes
Cycloalkane
(Carbon Atoms)
Molecular Formula
Shortened Structural Formula
Full Structural Formula
Cyclohexane (6)
C6H12
Cycloheptane
(7)
Cyclooctane
(8)
C8H16

12. General Formula for cycloalkanes is CnH2n
The number of Hydrogen atoms = 2 times the number of Carbon atoms
General Formula for cycloalkanes is CnH2n