Chemical Resources

1. Deeper = Hotter

1. Pangea: Old supercontinent
2. Explains wide range of evidence e.g. 'Puzzle Piece' atlas
3. Wegener's continental drift theory (1914) not initially accepted.

1. Iron-rich Basalt: Runny lava
2. Silica-rich Rhyolite: Viscous lava
   1. Explosions!

1. E.g. Granite > Marble > Limestone
   1. Granite
      1. Cooled Magma
      2. Igneous
      3. Interlocking Crystals
   2. Marble
      1. Metamorphic
      2. Limestone changed by heat+pressure
      3. Baked, therefore Marble>limestone
   3. Limestone
      1. Sedimentary - compressed and cemented sediment

1. One material heated --> 2+ new substances
2. Calcium Carbonate (Limestone):
   1. CACO3 --> CaO + CO2
      1. (Limestone) -->
      2. (Calcium oxide + Carbon Diox.)
3. Cement = Limestone + Clay + HEAT
   1. Concrete = Cement + Sand/Stones + Water
      1. Reinforced concrete: Steel rods/mesh
         1. Composite material: Both distinguishable
         2. Concrete weak under tension
            1. Steel stops stretching/cracking

1. Mixtures containing 2+ metals
2. Amalgam (Mercury): Fillings
3. Brass (Copper + Zinc)
4. Solder (Lead + Tin)
5. Smart alloys - Retain shape when heated
   1. E.g. Glasses frames of Nititol (Nickel-Titanium)

1. Advantages:
   1. Low melting point, little energy
   2. Reduces mining
   3. Reduces copper cost
2. Disadvantages:
   1. Small amounts in electrical equipment
      1. Difficult to separate
   2. Pure and impure cannot be mixed (e.g. Solder)
   3. Fewer mining jobs
   4. May produce pollution
3. Pure Cathode (-)
   1. Gains mass
   2. Cu(2+) Ions + 2e- --> Cu atoms
4. Impure Anode (+)
   1. Loses mass
   2. Drops impurities
   3. Cu atoms --> Cu(2+) +2e-

1. Iron and Steel rust: Other metals corrode
2. Acid rain + Salt water accelerate
3. Is Oxidation:
   1. Iron + Oxygen + Water --> Hydrated Iron (III) Oxide

1. Aluminium: lightweight, malleable, no corrosion
2. Iron/Steel: Malleable, strong
3. Plastics: No corrosion, cheap

1. Steel stronger than iron
2. Steel less likely to corrode than iron

1. Improve fuel economy
2. Less corrosion, will last

1. Advantages: Less mining, less crude oil in plastics, less landfill
2. Disadvantages: Fewer mining jobs, difficult to separate, can pollute, expensive
3. Minimum Recyclable % laws in place

Anotações:

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1. Optimum Conditions
   1. Iron Catalyst incr. rate of reaction (NOT percentage yield)
   2. High pressure incr. Ammonia yield
   3. High temperature incr. rate of reaction
   4. High temp. REDUCES Ammonia yield
      1. Optimum temp. 450'C
         1. Quick, low yield

1. High pressure = High plant costs
2. High temp = High energy costs
3. Catalysts increase reaction
4. Automation reduces wage costs (workers)
5. Aim for cheapest yield, not fastest/ largest

1. Metal oxides/hydroxides
2. Those soluble in water called ALKALIS
   1. Sodium hydroxide, calc. hydroxide
3. Alkalis contain OH- ions

1. Acid + Base --> Salt + Water
   1. H+ (Acid) + OH- (Alkali) <---> H2O

1. Shows gradual changes

1. All contain H+ ions
2. Higher the H+ concentration, lower the pH

1. Acid + Metal carbonate --> Salt + Water + CO2
2. Two-part names:
   1. Sulfate, nitrate, chloride, phosphate
3. E.g: Hydrochloric acid + copper carbonate --> Copper chloride + water + carbon dioxide

1. Fertilisers must be dissolved in water for plant roots to absorb
2. Some dissolve easily, others designed for slow energy release
3. Yield increased by:
   1. Provide extra essential elements
      1. (Fertiliser)
   2. Provide nitrogen encorporated into plant protein
      1. Increased growth

1. Excess fertiliser runoff causes algal bloom in river systems
   1. Sunlight blocked out
      1. Plants stop respiring
         1. Aerobic bacteria use all oxygen
            1. Fish die
2. Caused by nitrate / phosphate levels

1. Most fertilisers are salts
   1. (Water is heavy to transport)
2. Step 1: Titrate alkali and acid using indicator to find neutral
   1. Step 2: Use these ratios to scale up alkali + acid
      1. Step 3: Boil off most water, leave to crystalise

1. Rock salt mined from ground
2. Pump water underground, collect salt solution
3. Can cause subsidence - destroys land + homes
4. Leaking brine solution affects habitats

1. Brine can be separated using electrolysis.
2. Important the electrodes are INERT
   1. (Chlorine and Hyrdogen are highly reactive)
3. Equations:
   1. Ions not discharged make Sodium Hydroxide solution
      1. Na+ + OH- --> NaOH
   2. Chlorine OXIDISED at anode
      1. 2Cl- - 2e- --> Cl2
   3. Hydrogen REDUCED at cathode
      1. 2H+ + 2e- --> H2

1. Chlorine and Sodium Hydroxide important raw materials
   1. Bleach
   2. Paints
   3. Solvents
   4. Plastics
   5. Foods