Reaction between Acids and Alkalis or between Acids and Bases
Combustion Complete
When a substance usually hydrocarbon is completely burnt to form carbon dioxide and water only in the presence of abundance of oxygen
Combustion Incomplete
When a substance usually hydrocarbon is burnt to form carbon (or soot), carbon monoxide, carbon dioxide and water due to limited and low amounts of oxygen
Precipitation
When two aqueous solutions each containing a soluble substance are mixed and a solid precipitates out