Metals
Physical propeties
Ductile/Malleable
High density (excluding Grp 1)
Good conductor of heat/electricity
High mp/bp
Shiny
metal atoms same size, arranged in orderly layers. When force applied, layers can slide over one another
metal atoms closely packed, many particles per unit vol
strong metallic bond (between + metal ion & 'sea' of mobile electron), a lot of energy needed to overcome strong metallic bond
Alloys
mixture of a metal with one or more other elements
Physical properties
Harder & stronger
Different sized atoms of another element, disrupt orderly arrangement of atoms, harder for atoms in alloy to slide over one another
Better appearance
More corrosion resistant
Lower mp/bp
Reactivity series
Please Stop Calling Me A Crazy (carbon) Zebra. I Like Hissing (hydrogen) Cobras So Go (further down, less reactive)
Reactions
Metal + Cold water --> Metal hydroxide + Hydrogen
Metal + Steam --> Metal oxide + Hydrogen
Metal + Acid --> Salt + hydrogen
Displacement
More reactive metal displaces less reactive metal
Decomposition of metal carbonate (breaks down from heat)
CaCO3 (s) → CaO (s) + CO2 (g)
(from blast furnace reaction)
Metal carbonate --> metal oxide + carbon dioxide
Reduction (reduced by hydrogen or carbon)
Metal oxide + hydrogen/carbon --> metal + steam (H2O g) OR metal + carbon dioxide
Metal + cold water (Please stop calling me)
Metal + acid/steam (Please stop calling me, Zebra I)
Heating of metal carbonate
Group 1 (KN) - unaffected by heat
Ca - Cu - decompose into metal oxide + carbon dioxide
Ag - decompose into silver + carbon dioxide
Silver oxide produced is thermally unstable → will decompose further to silver
Extracting metals
Electrolysis - K to Al
Reduction (with H or C or CO) - Z to Ag
*Gold - naturally uncombined
Extraction of Iron
Raw materials
Haematite (Iron (II) oxide)
Coke, Carbon, C
Limestone, calcium carbonate
Hot air, O2
Equations
Products
Slag, CaSiO3
Molten iron
Waste gases
Rusting
Conditions needed
Oxygen (from air)
Water
Speed up
Presence of NaCl, saltwater
Acidic substance
Slow down
Boiled water --> removes oxygen
Presence of anhydrous calcium chloride (drying agent → remove moisture) → removes water vapour
Oil on surface of water → prevent entry of oxygen into water
Prevention
Protective layer, Acts as a barrier to prevent water and oxygen in air from coming into contact with iron surface
Using a sacrificial metal
Using alloy
Recycling metals
metals are finite resources
conserves limited fossil fuel resources +
reduces damage to environment +
time and effort are needed for people to practice recycling as a lifestyle -
cause pollution problems. Harmful gases produced when lead from car batteries is recycle -
more expensive as costs are needed to also collect, sort, separate, clean and transport old metal -