chapter 14 Flashcards
Oxidation Reaction
When a substance reacts with oxygen.
Neutralisation Reaction
An acid and a base reacting to form salt and water.
Electrolysis Reaction
Produced by electricity or produces electricity.
Decomposition Reaction
Breaking down a substance into simpler compounds.
Law of Conservation of Mass
In a reaction the total mass of reactants always equals the total mass of the products.
Hydrocarbon
A compound that contains hydrogen and carbon.
Testing for Oxygen in the Air
Copper turnings are put in silicia glass tubing with a gas syringe at each end. As they are heated using a bunsen burner, air is passed over them using syringes. Copper + Oxygen = Copper Oxide.
Observed that approximately 20cm cubed of air used up, i.e: Air contais 20% oxygen.
The Fire Triangle
- Fuel
- Heat
- Oxygen
Incomplete combustion of fuel word equation
Fuel (hydrocarbon) + oxygen = carbon monoxide + water
Incomplete combustion of fuel
When there is not enough oxygen for complete combustion of fuel the reaction will not be completely finished.
Carbon Monoxide (CO)
Colourless, odourless, toxic gas
Preventing poisoning by carbon monoxide
Boilers should be regularly serviced.
Rooms should be well ventilated.
Carbon monoxide detectors should be installed.
Metal + Water = Metal oxide/metal hydroxide and hydrogen
Metal oxide/metal hydroxide and hydrogen
Sodium + Water=
Sodium hydroxide + Hydrogen
Metal + Oxygen=
Metal oxide
Magnesium + Oxygen=
Magnesium Oxide
Corrosion
The gradual reaction of metals with water and oxygen in their environment. A metal oxide is formed.
Corrosion of iron
Iron oxide is formed (red) on the surface of the metal but this flakes off allowing iron underneath to be corroded further. Oxygen and water are both neede for iron to corrode.
Preventing Corrosion
- Painting the metal
- Covering metal with plastic coating
- Greasing moving parts of metal with oil.
- Galvinising: Covering with thin layer of a metal that doesn’t rust, e.g chromium, zinc.
Reactivity Series of Metals
Scientists use this to show metals in order of reactivity, e.g: if they react with water they are very reactive, but if they won’t react with oxygen they are very unreactive.
One reason why Gold, Platinum and Silver are so valuable
They are unreactive and will never corrode. They remain shiny.
Ion
A charged atom.
Ionic Bond
A force of attraction between two oppositely charged ions in a compound.
Covalent Bond
Formed when pairs of electrons are shared between two atoms.
Coefficient
The number in front of the formula which indicates the tital number of molecules or ions of each kind involved in the reaction.
Subscript
The number to the lower right of the chemical symbol which indicates the number of atoms of that element found in the compound.
Valency
The combining power of the element. It is the number of bonds that elements need to form in a compound.
Fuel (hydrocarbon) + oxygen =
carbon dioxide + water
