Section 2- Metals

Extracting Metals:

• are linked to the order of reactivity 

1. Only metals less reactive than carbon can be extracted by a reduction reaction with carbon ----------> heating the ore with carbon monoxide 
• more reactive elements form compounds more readily 
• reduction= loss of oxygen 
2. Hydrogen: metals above H react with acids to release H2 

Extracting Iron:

(Blast Furnace) 

Raw materials:

1. Iron ore -----> iron
2. Coke -----> almost pure carbon; reducing iron oxide to iron metal
3. Limestone -----> take away impurities from slag 
4. Air ------> allows the coke to burn 

Reducing Iron ore to Iron:

1. Hot air blasted into the furnace -----> coke burns faster than normal. Raises to 1500C.  
2. Coke burns and produces carbon dioxide:
• Carbon and Oxygen ------> Carbon Dioxide 
• C            +        O2    ------> CO2 
3. Carbon monoxide 
• Carbon dioxide and Carbon -----> Carbon monoxide 
•          CO2          +         C     ----->          2CO 
4. Carbon monoxide then reduces the iron ore to iron
• Carbon monoxide + Iron(II) oxide ------> Carbon dioxide + Iron
•          3CO             +       Fe2O3       ------>        3CO2        +  2Fe 
5. Iron is molten at temperature also dense so goes to the bottom where it's tapped off 

Removing impurities: 

Slag forms as CaO from limestone reacts with rocks (SiO2) 

CaCO3 -----> CaO + CO2 

CaO + SiO2 ------> CaSiO3 (molten slag) 

• Coolen to solid and used for:
• road building 
• fertiliser 

Uses of Iron:

• steel 
• buildings
• car radio 
• railings

REDOX -------> reduction and oxidation occur together 

Oxidising Agent --------> produces Oxygen (O2) in the process. reduced itself

Reducing Agent --------> gains Oxygen (O2) in the process. oxidising itself

Rusting of iron:

• needs water and oxygen (from air) 
• doesn't rust in boiled water or dried air 

How to prevent rusting?

Barrier methods: 

• paint 
• plastic coat 
• tin plate 
• grease 
• coat in zinc 

Sacrificial methods: 

• Attach above (more reactive) metal to the iron (e.g. zinc)