3.4 I can recall the products of the complete and incomplete combustion of alkanes

Saturated hydrocarbons are called alkanes.
Small chain molecules are used as fuels.
The reaction is called combustion.
The word equation for this chemical reaction is
fuel + oxygen -> carbon dioxide + water + energy (heat, light, sound)
If there is insufficient oxygen then the word equation is:
fuel +inefficient oxygen -> water + carbon monoxide + energy (heat,light,sound)
The problem with this reaction is that carbon monoxide is produced this gas is a poison to the human body.
Where can you find incomplete combustion?
You can find incomplete combustion in car engines.
What is used to reduce the harmful products from incomplete combustion?

During incomplete combustion a smoky flame is often seen, explain this observation.

Describe the chemical test for carbon dioxide gas?
Limewater turns milky.
Describe a physical test for water?
Heating water in a beaker, and it's boiling point will be 100 degrees.