Nature's Chemistry Flashcards
What is a fuel?
A fuel is a compound that contains stored energy.
What happens when a fuel burns?
It reacts with oxygen to release energy; this is known as combustion.
What are the three conditions needed for a fire using the fire triangle?
Oxygen, Heat and Fuel
What is combustion an example of?
Exothermic Reaction
Name four examples of fossil fuels
Coal, Natural Gas, Crude Oil and Peat
How is coal and peat formed?
It was formed from trees and plants falling into the swamps millions of years ago. The vegetation decayed due to lack of oxygen and was put under immense pressure from the layers covering it. Initially peat is formed but if the peat is put under huge pressure it will turn into coal.
How is crude oil and natural gas formed?
When plants and animals died millions of years ago, they fell to the bottom of the ocean where they were gradually buried under other plants and animals. Over the years layers of rocks crushed them, helping them decay without oxygen. Most of the oil and gas was trapped underneath the rocks.
What is crude oil a mixture of?
Hydrocarbons
How is crude oil separated into fractions?
They are separated using fractional distillation.
What is Fractional Distillation?
Fractional Distillation is a method used to separate crude oil compounds. The compounds are collected over a boiling range for example 60-120°C, and are known as fractions. The process starts by heating the crude oil to produce gases, the gases rise up the column with the fractions with higher boiling points condense at the bottom and those with lower boiling points higher up.
Name three useful substances that come from crude oil
Petrol, Diesel and Kerosene
What is a hydrocarbon?
A molecule that contains only carbon and hydrogen
What are the simplest family of hydrocarbons called?
Alkanes
Name the first eight Alkanes
Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane and Octane
Describe the shape of a methane molecule
Four hydrogens and one carbon
