Fuels

Exothermic Reaction

An Exothermic reaction transfers thermal energy to the surroundings therefore losing heat this leads to an increase in the temperature of the surroundings.

Exothermic reaction involves bond making

Example: Burning

Endothermic Reaction

Takes in thermal energy from the surroundings therefore gaining heat this leads to a decrease in temperature of the surroundings

Endothermic reaction involves bond breaking

Examples: Ice cube melting, respiration

Reaction Pathway Diagrams

Activation Energy

Activation Energy is the minimum energy that colliding particles must have to react

Which is an endothermic process

Bond Breaking

What is an exothermic reaction

Bond Making

3 Main fossil fuels

Coal, Natural gases, Petroleum

Main constituent of Natural gases

Methane

What are hydrocarbons

Compounds that contain : Hydrogen and Carbon

Petroleum is a mixture of _____________

Petroleum is a mixture of Hydrocarbons

Fractional Distillation: Petroleum/ Crude Oil

Fractional Distillation is the separation of petroleum(crude oil) utilizing the different boiling points in the mixture

Describe how the fractionating column separates the crude oil

The Crude oil gets heated to a vapour and enters the fractionation coloumn, which then rise through the column. As the vapours rise, they cool and condense at different levels according to their boiling points, with higher-boiling (larger, more viscous, less volatile) fractions collecting at the bottom and lower-boiling (smaller, less viscous, more volatile) fractions collecting at the top. These distinct collections of hydrocarbons, called fractions, are then collected for various uses

uses of fractions in fraction distillaion

Properties of hydrocarbons

Saturated Compounds

A Saturated compound is a compound which all carbon bonds are single bonds

Unsaturated Compounds

A Unsaturated compounds is a compound is which one or more carbon bonds are not single bonds

Homologous Series

Homologous Series is a family of similar compounds with similar chemical properties

General Characteristics of Homologous Series

• Having the same general formula

• Displaying a trend in physical properties

Manufacture of Alkenes and Hydrogen- Cracking

Alkenes and hydrogens are produced by the cracking of larger alkane molecules

Cracking:

• Thermal Cracking- by using high temperature and pressure to break the bonds

• Catalytic Cracking- by using a low temperature and pressure with a catalyst

They are separated by fractional Distillation

Bonds in Alkenes

Includes a double carbon covalent bon and alkenes are unsaturated hydrocarbons

Test: Distinguish between saturated and unsaturated hydrocarbons

Bromine Water is used to tell the difference between an alkane and alkene

An alkene will turn brown bromine water colourless

An alkane will stay brown

Polymers

Polymers are large molecules built up from many smaller molecules called monomers

Formation of Polyethene

Formation of Polyethene is an example of additional polymerisation using ethene (an alkene) monomer

poly- multi