Chemistry- Reactions

• oxidation is a process in which a chemical substance changes because of the addition of oxygen
• Test for oxygen: insert a glowing splint into the gas, if the gas is oxygen the splint will relight
• Word equation for oxidation: Metals + oxygen --> metal oxide
• Metal oxides are basic ( react with an acid to form a salt and water) they react with acids and neutralise(acid and a base react to form salt and water) them. Some metal oxides dissolve in water to produce alkaline (a base that is soluble in water) solutions
• Oxidation in non-metals: non metals + oxygen --> non-metal oxide
• Non-metals react with oxygen in the air to produce acidic oxides e.g. carbon + oxygen --> carbon dioxide
• metals are basic because metal oxides react with acids to form salt and water. Since they neutralize the acids so they are basic.
• Non-metal oxides are acidic- they react with bases and neutralise them. Some non-metal oxides dissolve in water to produce acidic solutions.
• Prevention of corrosion:

  Painting- prevents oxygen from coming in contact with metals

  Coating with a layer of zinc- slows corrosion because zinc is more reactive than iron
• Combustion is the process of burning fuel to release energy.
• Most fuels are hydrocarbons. These are compounds which contain carbon and hydrogen only
• Word equation for combustion: Hydrocarbon + oxygen --> carbon dioxide + water
• Incomplete combustion happens when there is limited amount of oxygen for fuel to react with.
• word equation for incomplete combustion: hydrocarbon + oxygen (limited) --> water + carbon dioxide + carbon monoxide
• Thermal decomposition is chemically breaking down a substance using heat
• Word equation example for Thermal decomposition: Copper carbonate --> copper oxide + carbon dioxide