Chemistry
- Created by: Lauren stenning
- Created on: 28-02-13 20:03
Bonding
Ionic Compounds = Metals and Non-metals, e.g carbon and oxygen - loss or gain of electrons, group 7 or 1
Covalent compounds = Non-metal and non-metal - sharing
Isotope = Atom with different amount of Neutrons to normal
Ion = Atom with different amount of electrons to normal (positively - lost an electron or negatively - gained an electron charged)
Limestone
Improves soil fertility
Soft rock - used for buildings
Calcium carbonate (CaCO3)
Calcium carbonate (Limestone) -> Calcium Oxide (Quicklime)+Carbon dioxide + Water -> Calcium Hydroxide (Slaked Lime) + Water ->Calcium Hydroxide (Lime Water)+Carbon Dioxide+Water->Calcium Carbonate (Limestone)
CaCO3->CaO+CO2+H2O->Ca(OH)2+H2O->Ca(OH)2 (aq)+CO2+H2O->CaCO3
THERMAL DECOMPOSITION
The more reactive the metal, the harder it is to thermally decompose. EXOTHERMIC reaction gives out heat when water is added.
Metals
Ores - combined with other elements
Native - Pure substances
- Create jobs
- Economic growth
- Pollution
- Health issues
Dense and Ductile
Metallic bonding = Free electrons (Delocalized) Unbreakable
Alloys = Mixtures of metal elements. Stronger than pure metal because of uirregular structure (different sized elements)
Extraction
Reduction By Carbon:
Below Carbon in reactivity series. Removing Oxygen (Always a metal Oxide). Not very pure or effective.
Blast Furnace:
- Limestone
- Iron ore
- Coke
Hot air, carbon dioxide made, reacts with coke to form carbon monoxide which reduces iron ore. 96% Pure.
Electrolysis
EXPENSIVE
Oxidation
Is
Loss (of electrons)
Reduction
Is
Gain (of electrons)
Pure metal from Anode (Positive, impure) to Cathode (negative, pure) Cu2+ + 2e- -> Cu
Leaching = Sulfuric acid to Copper sulfate then electrolysis (less electricity and waste gases)
Phytomining = Plants absorb metals from soil
Displacement
More reactive metals displace less reactive metals!!!
Hydrocarbons
Crude Oil
Larger, Higher boiling point (Stronger intermolecular forces, more energy needed to break bonds) Also more Viscous but hard to evaporate, very dark such as fuel oil. LPG has very short chains so its light and easily evaporated with a low boiling point.
FRACTIONAL DISTILLATION
VISCOSITY = runniness
AlkANES = Single bonds (CnH2n+2) SATURATED
Monkeys eat peanut butter
AlkENES = Double bonds (CnH2n) Test: Add Bromine, colourless = Double bond as bonds are broken. Brown = Single bonds (no reaction) UNSATURATED
Alchols = single hydroxide bond (OH)
Carboxylic Acids = Double bonded Oxygen and single bonded Hydroxide
Hydrocarbons continued
Halogenalkanes/alkenes = One hydrogen replaced with another element such as Chlorine (Chlorohydrocarbon)
Catalystic cracking:
A catalyst speeds up a reaction. It is used in thermal decomposition. Hydrocarbon molecules heated into vapour and mixed with catalyst. This forms smaller chains. The chains are called polymers and single molecules are called monomers. Plastics are polymers. When Monomers join together to make polymers its called addition polymerization. The double bonds of alkenes are broken to become alkanes.
Pollution
Lung damage/respiratory diseases from pollutant particles. Particles in blood lowers oxygen carrying capacity. Acid rain is a direct result of pollutant gases. Can kill fish (water too acidic).
Global warming/greenhouse effect, adaption
CO2, SO2(BURNING COAL), NO2
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