Fuels and Energy
National 3 Unit 2 – Nature’s Chemistry
What is a fuel?
A fuel is a substance that can be burned to release energy
The Fire Triangle
A fire needs 3 things in order to keep burning:
If the fire is starved of one or more of these it will go out.
Fire Extinguishers
Different fire extinguishers are used for different fuel
sources.
Video
Combustion
Fuels containing only carbon and hydrogen atoms are known as
hydrocarbons.
When a hydrocarbon burns it is known as combustion.
Hydrocarbon + oxygen
carbon dioxide + water
You can test for the production of carbon dioxide using lime water:
Carbon dioxide turns lime water cloudy
Different Fuels
Here are some different fuels with some advantages and
disadvantages:
Fuel
Advantage
Disadvantage
Petrol
Provides a lot of energy
It is a finite resource- it will eventually
run out
Alcohol
It is renewable – can be remade
Need a lot of landmass to make it
Biomass
It is renewable – can be remade
It is expensive to make them
Everyday Consumer
Products
National 3 Unit 2 – Nature’s Chemistry
Plants
Plants (producers) are the first source of energy in all food
chains.
They change light energy from the sun into chemical energy
that animals (consumers) can use.
Fertilisers
Fertilisers are chemicals that are used to help plants grow.
They contain minerals that the plant needs in order to grow
into a big, healthy plant.
Food from Plants
Plants make and store food in the form of starch.
We know this because when iodine solution is placed on a
leaf, it turns a blue/black colour
Test for starch:
Iodine solution turns
from brown to
blue/black
Alcohol from Plants
Some plants can be used to make alcohol by fermentation.
Fermented Plant
Grapes
Potatoes
Apples
Alcohol Produced
Wine
Vodka
Cider
Harmful Effects of Alcohol
Alcohol can damage the body in the following ways:
Plants to Products
National 3 Unit 2 – Nature’s Chemistry
Products from Plants
Plants can be used to make products we use daily
Plant
Product
Poppy
Morphine
Flax
Linen
Aloe Vera
Moisturising cream
Lemon
Shampoo
Lavender
Soap
Peppermint
Mouthwash