Fractional Distillation

Fractional distillation is the process of separating crude oil into groups of hydrocarbons with similar numbers of carbon atoms. We call these groups of hydrocarbons “fractions”.

Long-chain hydrocarbons

Hydrocarbons with lots of carbon atoms are called ‘long-chain hydrocarbons’.

Short-chain hydrocarbons

Hydrocarbons with few carbon atoms are called 'short-chain hydrocarbons'.

The Process of Fractional Distillation

Different-sized hydrocarbons have different boiling points. Fractional distillation separates hydrocarbons using their different boiling points. The steps of the process are:

Evaporation

We evaporate the crude oil by heating it.
Crude oil vapour is put into a fractionating column at the bottom and rises upwards.

Condensation

The temperature is highest at the bottom of the column. Long-chain hydrocarbons condense at the bottom and are collected as liquids.
Short-chain hydrocarbons have lower boiling points. They pass up the column and condense at lower temperatures nearer the top.

Collection

The fractions are collected. They are then processed to create end products:
- Fuels (e.g. petrol, diesel) are a common end product.
- The petrochemical industry can use some fractions as feedstock (material used in an industrial process) to make products such as solvents, detergents, lubricants etc.

1Atomic Structure

2Chemical Bonding

2.1Chemical Bonds

2.1.1Types of Bonds

2.1.2Ionic Bonds

2.1.3Ionic Compounds

2.1.4Covalent & Metallic Bonds

2.1.5Representing Covalent Bonds

2.1.6Dots-And-Cross Diagrams

2.1.7Exam-Style Questions - Chemical Bonds

2.2States of Matter

2.2.1States of Matter

2.2.2Changing State

2.2.3Changing State HyperLearning

2.2.4State Symbols

2.2.5Exam-Style Questions - States of Matter

2.3Chemical Properties

2.3.1Chemical Properties of Ionic Compounds

2.3.2Chemical Properties of Small Molecules

2.3.3Molecular Forces & Polymers

2.3.4Metals & Giant Covalent Structures

2.3.5Alloys & Conductors

2.3.6Carbon Structures - Diamond & Graphite

2.3.7Carbon Structures - Graphene & Fullerenes

2.3.8Carbon Structures - Summary

2.3.9Nanoparticles

2.3.10Nanotechnology

2.3.11Surface Area to Volume Ratio & Nanotechnology Uses

2.3.12End of Topic Test - Chemical Bonding

2.3.13Grade 9 - Bonding & Structure

2.3.14Exam-Style Questions - Allotropes of Carbon

3Quantitative Chemistry

4Chemical Changes

5Energy Changes

5.1Exothermic & Endothermic Reactions

5.1.1Energy Conservation

5.1.2Exothermic & Endothermic Reactions

5.1.3Reaction Profiles

5.1.4Reaction Profiles 2

5.2Chemical Cells & Fuel Cells

5.2.1Chemical Cells

5.2.2Batteries & Charging of Cells

5.2.3Fuel Cells

5.2.4Hydrogen Fuel Cell

5.2.5End of Topic Test - Energy Changes

5.2.6Grade 9 - Energy Changes

5.2.7Exam-Style Questions - Fuel Cells

6The Rate & Extent of Chemical Change

6.1Rate of Reaction

6.1.1Chemical Reactions

6.1.2Collision Theory

6.1.3Catalysts

6.1.4Catalysts in Industry

6.2Reversible Reactions

6.2.1Reversible Reactions

6.2.2Equilibrium

6.2.3Equilibrium Position

6.2.4Equilibrium Position 2

6.2.5End of Topic Test - Rates of Reaction

6.2.6Grade 9 - Rate & Extent of Chemical Change

6.2.7Exam-Style Questions - Reversible Reactions

7Organic Chemistry

8Chemical Analysis

8.1Purity, Formulations & Chromatography

8.1.1Purity & Formulations

8.1.2Chromatography

8.1.3Paper Chromatography 1

8.1.4Paper Chromatography 2

8.1.5Required Practical - Paper Chromatography

8.2Identification of Common Gases

8.2.1Identification of Hydrogen & Oxygen

8.2.2Identification of Carbon Dioxide & Chlorine

8.3Identifying Ions

8.3.1Flame Tests

8.3.2Required Practical: Flame Tests

8.3.3Metal Hydroxides

8.3.4Carbonates

8.3.5Halides, Sulfates

8.3.6Methodology for Chemical Analysis

8.3.7Flame Emission Spectroscopy

8.3.8End of Topic Test - Chemical Analysis

8.3.9Grade 9 - Chemical Analysis

8.3.10Exam-Style Questions - Identification of ions

9Chemistry of the Atmosphere

9.1The Earth's Atmosphere

9.1.1Proportions of Gases in the Atmosphere

9.1.2Oxygen & Carbon Dioxide in the Atmosphere

9.1.3Greenhouse Gases & Human Activities

9.1.4Greenhouse Gases & Human Activities

9.1.5Greenhouse Gases & Climate Change

9.1.6Carbon Footprints

9.1.7Common Atmospheric Pollutants & Their Properties

9.1.8End of Topic Test - The Earth

9.1.9Grade 9 - Chemistry of the Atmosphere

9.1.10Exam-Style Questions - Earth's Atmosphere

10Using Resources

10.1Using the Earth's Resources

10.1.1Potable Water & its Sources

10.1.2Potable Water in the UK & in Saudi Arabia

10.1.3Natural Resources

10.1.4Waste Water

10.1.5Metal Ore Extraction & the Properties of Copper

10.1.6Overexploitation & Alternative Extraction Methods

10.2Life Cycle Assessments & Recycling

10.2.1Life Cycle Assessments

10.2.2Difficulties with LCA

10.2.3Reducing Resource Usage

10.2.4Reducing Use of Metal and Glass

10.2.5Exam-Style Questions - Life Cycle Assessments

10.3Using Materials

10.3.1Corrosion

10.3.2Alloys

10.3.3Ceramics

10.3.4Polymers & Composites

10.4The Haber Process & NPK Fertilisers

10.4.1The Haber Process

10.4.2The Haber Process - Equation & Trade-Offs

10.4.3Formulated vs Manure Fertilisers

10.4.4NPK Fertilisers 1

10.4.5NPK Fertilisers 2

10.4.6End of Topic Test - Resources

10.4.7Grade 9 - Using Resources

10.4.8Exam-Style Questions - The Haber Process

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