Chemistry: CR

Starting from most recting going down.

• K = Potassium
• Na = Sodium
• Ca = Calcium
• Mg = Magnesium
• Al = Aluminium
• Zn = Zinc
• Fe = Iron
• Pb = Lead
• H = Hydrogen
• Cu = Copper
• Ag = Silver
• Au = Gold

Yellow = does not react

Group 1 metals: these are called alkali metals. They are a familu of metals with similar chemical properties. They are rather unusual metals because they are soft and have fairly low melting points. The melting and boiling points decrease as they go down the group. The metals get softer down the group. There is a general increase in desity down the group.

They react readily with water to produce hydrogen gas and an alkali soultion of a metal hydroxide. Their reactivity increases down the group. Lithiumfizzes slowly on the surface of the water but potassium fizzes rapidly and the hydrogen produced catches fire.

Displacement reaction: A more reactive metal displaces a less reavtive metal form a solution or a salt. This is becasue the more reactive metal loses its vaency electrons more easily.

Oxidation: Is when an Ion losses electron(s).

Reduction: Is when an Ion gains electron(s).

Oxidation: The ion looses and electron.

Reduction: The ion gains and electron.

Oxidising agent: Something which causes something else to be oxidised (so itself reducted).

Reduction agent: Something which causes something else to be reduced (So itself oxidied)

Extracting Iron: Raw metails for making iron are haematite, coke, limestone and aire. They are added to the top of the blast furnace. A strong current of hot air is blown in at the bottom of the furnace. this air is between 550oc and 850oc.

For all the equation for the blat furnace look at pages 172 and 175

We extract Iron form Iron ore in a blast furnace. The commonest ore of Iron is Haematite. The other raw materials used are coke, limestone and air. Inside the blast furnace, carbon monoxide reduces the Iron(iii) oxide to Iron.

What causes rust: chemicals in the aire may attack metals causing the surface to get eaten away. We call this corrosion. Rusting is the corrosion of the iron and steel. only Iron and steel rust. For rusting to occur both water and oxygen are needed. Rusting is an oxidation reaction.

Rusting occurs when oxygen and water react with iron or steel. Rust is hydrated Iron(iii) oxide. The layer of rust easily flakes off the surface of the iron. The fresh iron surface then starts to rust.

Stopping the rust: Paint, a plastic coating, metal plating (the iron is covered in another metal e.g galvanising) and Greasing and oiling (used for tools and moving parts of machinery).