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C2A - The Structure of the Earth

EARTH'S STRUCTURE - SPERE SHAPE CONSISTING OF 4 LAYERS - CRUST, MANTLE, OUTER AND INNER CORE

  • CRUST - THIN OUTER LAYER (ABOUT 20KM DEEP) OF SOLID ROCK
  • LITHOSPHERE - CONSISTS OF UPPER MANTLE AND CRUST - FAIRLY SOLID - MADE UP OF A JIGSAW OF TECTONIC PLATES - RELATIVELY COLD AND RIGID - OVER 100KM THICK IN PLACES
  • MANTLE - SOLID SECTION BETWEEN CRUST AND CORE - NEAR CRUST IS VERY RIGID - TEMPERATURE INCREASES THE DEEPER INTO THE MANTLE YOU GET - BECOMES LESS RIGID - FLOWS VERY SLOWLY
  • CORE - JUST OVER HALF THE EARTHS RADIUS - INNER CORE IS SOLLID - OUTER CORE IS LIQUID
  • RADIOACTIVE DECAY - CREATES HEAT INSIDE EARTH - HEAT CREATES CONVECTION CURRENTS IN MANTLE - CAUSES PLATES IN LITHOSPHERE TO MOVE

TECTONIC PLATES - BID ROCKY RAFTS THAT FLOAT ON MANTLE (LESS DENSE THAN MANTLE) 

  • ROUGHLY A PLATE UNDER EACH CONTINENT - AS THEY MOVE, THE CONTINENTS MOVE
  • MOVE VERY SLOWLY - ABOUT 2.5CM PER YEAR
  • VOLCANOES AND EARTHQUAKES - CAUSED BY MOVEMENT OF PLATES AGAINST EACHOTHER - OFTEN OCCURS WHEN PLATES MEET 
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C2A - The Structure of the Earth

SEISMIC WAVES

  • DIFFICULT TO STUDY INNER STRUCTURE OF EARTH - CRUST TOO THICK TO DRILL THROUGH 
  • SCIENTISTS USE SEISMIC WAVES PRODUCED BY EARTHQUAKES OR BY SETTING OFF BIG MAN MADE EXPLOSIONS UNDERNEATH SURFACE OF EARTH TO STUDY STRUCTURE
  • MEASURE TIME IT TAKES TO WAVES TO TRAVEL THROUGH EARTH AND WHERE THEY'RE DETECTED - DRAW CONCLUSIONS ABOUT STRUCTURE
  • TWO TYPES OF WAVESS WAVES CAN TRAVEL THROUGH MANTLE - SHOWS MANTLE IS SOLID
    • P WAVES - GO THROUGH SOLIDS AND LIQUIDS
    • S WAVES - ONLY GO THROUGH SOLIDS
  • S WAVES NOT DETECTED IN CORES SHADOW - OUTER CORE IS LIQUID
  • P WAVES - TRAVEL FASTER THROUGH MIDDLE OF CORE - SUGGESTS INNER CORE IS SOLID
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C2A - The Structure of the Earth

UNEXPLAINED OBSERVATIONS ABOUT EARTH

  • FOSSILS OF VERY SIMILAR PLANTS AND ANIMALS FOUND ON DIFFERENT SIDES OF ATLANTIC OCEAN
  • FOR YEARS PEOPLE THOUGHT IT WAS BECAUSE CONTINENTS HAD BEEN LINKED BY 'LAND BRIDGES' WHICH HAD SUNK OR BEEN COVERED BY WATER WHN EARTH COOLED
  • COASTLINES OF AFRICA AND SOUTH AMERICA FIT TOGETHER
  • FOSSILS OF SEA CREATURES FOUND IN ALPS

EXPLAINING OBSERVATIONS

  • 1914 - ALFRED WEGENER - THEORY OF 'CONTINENTAL DRIFT HYPOTHESISED THAT AFRICA AND SOUTH AMERICA HAD PREVIOUSLY BEEN ONE WHICH THEN SPLIT
  • EVIDENCE - MATCHING LAYERS OF ROCKS AND MATCHING EARTHWORMS ON DIFFERENT CONTINENTS
  • SUPPOSED THAT 15 MILLION YEARS AGO THERE HAD BEEN ONE SUPERCONTINENT WHICH HE CALLED PANGEA - SPLIT INTO SMALLER CHUNKS (MODERN DAY CONTINENTS) WHICH ARE STILL DRIFTING APART
  • WHY THEORY WAS NOT IMMEDIATELY ACCEPTED
    • WEGENERS EXPLAINATION OF HOW DRIFTING HAPPENED (CAUSED BY TIDAL FORCES AND EARTHS ROTATING) PROVED IMPOSSIBLE BY GEOLOGISTS AND MOVEMENT NOT DETECTABLE
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C2A - The Structure of the Earth

OVERWHELMING EVIDENCE OF CONTINENTAL DRIFT

  • 1960'S - SCIENTISTS INVESTIGATED MID ATLANTIC RIDGE - RUNS WHOLE LENGTH OF ATLANTIC - FOUND THAT MAGMA (MOLTEN ROCK) RISES UP THROUGH SEA FLOOR, SOLIDIFIES AND FORMS UNDERWATER MOUNTAINS - ROUGHLY SYMMETRICAL EITHER SIDE OF RIDGE - SUGGESTED SEA FLOOR WAS SPREADING
  • MAGNETIC ORIENTATION OF ROCKS - AS LIQUID MAGMA ERUPTS OUT OF GAPS, IRON PARTICLES IN ROCKS ALIGN THEMSELVES WITH EARTHS MAGNETIC FIELD - SET IN POSITION AS IT COOLS - EARTHS MAGNETIC FIELD SWAPS DIRECTION EVERY 0.5MILLION YEARS = ROCK ON EITHER SIDE OF RIDGE HAS BANDS OF ALTERNATE MAGNETIC POLARITY, SYMMETRICAL ABOUT RIDGE
  • CONVINCING EVIDENCE THAT NEW SEA FLOOR BEING CREATED - CONTINENTS MOVING APART
  • EVIDENCE COLLECTED BY OTHER SCIENTISTS SUPPORTED WEGENERS THEORY - GRADUALLY ACCEPTED

VOLCANOES - OCCUR WHEN MAGMA FROM MANTLE EMERGES THROUGH EARTHS CRUST

  • MAGMA RISES THROUGH CRUST - 'BOILS OVER' WHERE IT CAN - SOMETIMES VIOLENTLY IF PRESSURE RELEASED SUDDENLY 
  • MOLTEN ROCK BELOW SURFACE IS MAGMA - WHEN ERRUPTS ITS LAVA
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C2A - The Structure of the Earth

SUBDUCTION - CAUSES VOLCANOES

  • CRUST AT OCEAN FLOOR - DENSER THAN CRUST BELOW CONTINENTS
  • SUBDUCTION - TWO TECTONIC PLATES COLLIDE - DENSE OCEANIC PLATE FORCED UNDERNEATH LESS DENSE CONTINENTAL PLATE 
  • OCEANIC CRUST TENDS TO BE COOLER AT EDGES OF A TECTONIC PLATE - EDGES SINK EASILY - PULL OCEANIC PLATE DOWN
  • OCEANIC CRUST FORCED DOWN - MELTS - STARTS TO RISE - VOLCANOES FORM WHEN MOLTEN ROCK FINDS IT'S WAY TO SURFACE

IGNEOUS ROCK - MADE WHEN MOLTEN ROCK SOLIDIFIES

  • TYPE OF IGNEOUS ROCK DEPENDS ON SPEED MAGMA COOLS AND COMPOSITION OF MAGMA
  • SOME MAGMA PRODUCES IRON RICH BASALT - LAVA FROM THAT ERUPTION RUNNY AND FAIRLY SAFE
  • SOME PRODUCE SYLICA-RICH RHYOLITE - ERUPTION EXPLOSIVE AND VIOLENT - PRODUCES THICH LAVA 

PREDICTING VOLCANIC ERUPTIONS

  • GEOLOGISTS STUDY MAGMA MOVEMENT - ALLOWS MORE ACCURATE PREDICTIONS OF ERRUPTIONS
  • TRICKY - VOLCANOES UNPREDICTABLE - SCIENTISTS ONLY SAY IF ERUPTION IS MORE LIKELY - NOT SURE
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C2B - Construction Materials

SEDIMENTARY ROCK - FORMED FROM LAYERS OF SEDIMENT LAID DOWN IN LAKES OR SEAS

  • OVER MILLIONS OF YEARS LAYERS GET BURIED UNDER MORE LAYERS - WEIGHT PRESSING DOWN SQUEEZES OUT WATER
  • FLUIDS FLOWING THROUGH PORES DEPOSIT NATURAL MINERAL CEMENT

METAMORPHIC ROCKS - FORMED BY ACTION OF HEAT AND PRESSURE ON SEDIMENTARY OR IGNEOUS ROCKS OVER A LONG PERIOD OF TIME

  • MINERAL STRUCTURE AND TEXTURE DIFFERENT BUT CHEMICAL COMPOSITION OFTEN THE SAME
  • AS LONG AS ROCKS DON'T MELT THEY'RE CLASSED AS METAMORPHIC - IF THEY MELT INTO MAGMA THEY ARE NO LONGER ROCKS BUT MAY EMERGE EVENTUALLY AS IGNEOUS ROCKS

IGNEOUS ROCKS - FORMED WHEN MAGMA COOLS

  • CONTAIN DIFFERENT MINERALS IN RANDOMLY ARRANGED INTERLOCKING CRYSTALS - MAKES THEM HARD
  • GRANITE - VERY HARD IGNEOUS ROCK - IDEAL FOR STEPS AND BUILDINGS
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C2B - Construction Materials

LIMESTONE - SEDIMENTARY ROCK FORMED FROM SEASHELLS

  • MOSTLY CALCIUM CARBONATEAND A GREY/WHITE COLOUR
  • ORIGIONAL SHELLS MOSTLY CRUSHES - CAN STILL BE A FEW FOSSILISED SHELLS REMAINING
  • LIMESTONE HEATED - THERMALLY DECOMPOSES TO MAKE CALCIUM OXIDE AND CARBON DIOXIDE
  • CALCIUM CARBONATE ----> CALCIUM OXIDE + CARBON DIOXIDE
  •           CaCO3 (S)             ---->       CaO (S)          +      CO2 (G)

MARBLE - A METAMORPHIC ROCK FORMED FROM LIMESTONE

  • ANOTHER FORM OF CALCIUM CARBONATE
  • VERY HIGH TEMPS AND PRESSURES BREAK DOWN LIMESTONE - REFORMS AS SMALL CRYSTALS
  • GIVES MARBLE MORE EVEN TEXTURE - MAKES MARBLE A LOT HARDER

GRANITE - IGNEOUS ROCK

  • HARDER THAN MARBLE - CONTAIN VARIOUS DIFFERENT MINERALS IN INTERLOCKING CRYSTALS
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C2B - Construction Materials

  • ALUMINIUM AND IRON - EXTRACTED FROM ORES IN ROCKS - ORES MINERALS WE GET USEFUL MATERIALS FROM
  • GLASS - MADE BY MELTING LIMESTONE (CALCIUM CARBONATE), SAND (SILOCEN DIOXIDE) AND SODA (SODIUM CARBONATE) TOGETHER UNTIL IT MELTS - MIXTURE COOLS AND COMES OUT AS GLASS
  • BRICKS - MADE FROM CLAY (MINERAL FORMED FROM WEATHERED AND DECOMPOSED ROCK) - SOFT WHEN DUG UP - EASY TO MOULD INTO BRICKS - CAN BE HARDENED BY FIRING AT HIGH TEMPS - WITHSTAND WEIGHT
  • CEMENT- POWDERED CLAY/LIMESTONE ROASTED IN ROTATING KILN - MAKE COMPLEX MIXTURE OF CALCIUM AND ALUMINIUM CILICATES - MIXED WITH WATER - SLOW CHEMICAL REACTION - SETS HARD GRADUALLY
    • CAN BE MIXED WITH SAND, AGGREGATE, WATER TO MAKE CONCRETE - QUICK AND CHEAP WAY TO MAKE BUILDINGS - MAKES UNATTRACTIVE BUILDINGS
    • REINFORCED CONCRETE - COMPOSITE MATERIAL - COMBINATION OF CONCRETE AND SOLID STEEL SUPPORT - BETTER CONSTRUCTION MATERIAL THAN ORDINARY CONCRETE - COMBINES HARDNESS OF CONCRETE WITH FLEXIBILITY AND STRENGTH OF STEEL
  • ENVIRONMENTAL DAMAGE FROM EXTRACTING ROCKS - QUARRYING - USES UP LAND, DESTROYS HABITATS, PRODUCES DUST AND NOISE (DUE TO DYNAMITE USE) - TRANSPORTING ROCK - NOISE AND POLLUTION 
    • DISUSED SITES - VERY DANGEROUS - TURNED INTO DEEP LAKES (DROWNING) - DISUSED MINES COLLAPSE - CAUSE SUBSIDANCE
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C2C - Metals and Alloys

ELECTROLYSIS - SPLITTING UP METAL WITH ELECTRICITY

  • USED FOR EXTRACTING PURE COPPER - COPPER IMMERSED IN LIQUID WHICH CONDUCTS ELECTRICITY (ELECTROLYTE) - ELECTROLYTE USUALLY FREE IONS DISSOLVED IN WATER - COPPER (II) SULPHATE SOLUTION USED FOR EXTRACTING COPPER - CONTAINS COPPER 2+ IONS
  • ELECTRICAL SUPPLY ACTS AS ELECTRON PUMP - PROCESS - 
    • PULLS ELECTRONS OFF COPPER ATOMS AT ANODE - CAUSES THEM TO GO INTO SOLUTION AS Cu2+ IONS
    • OFFERS ELECTRONS AT CATHODE TO NEARBY Cu2+ IONS - TURN BACK INTO COPPER ATOMS
    • IMPURITIES DROPPED AT ANODE AS SLUDGE - PURE COPPER ATOMS BOND AT ANODE

(http://www.bbc.co.uk/staticarchive/6b2b7333efdec983e77acb2a468eafdeac08229a.jpg)

REACTION AT CATHODE - Cu2+ + 2e- --> Cu                  ANODE - Cu --> Cu2+ + 2e-

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C2C - Metals and Alloys

  • REDUCTION - LOSS OF ELECTRONS
  • OXIDATION - GAIN OF ELECTRONS
  • COPPER DISOLVES FROM ANODE - DEPOSITED ON CATHODE

RECYCLING COPPER 

  • CHEAPER TO RECYCLE COPPER THAN EXTRACT NEW COPPER
  • RECYCLING USES ONLY 15% ENERGY USED TO MINE AND EXTRACT
  • HARD TO CONVINCE PEOPLE IT'S WORTH EFFORT OF RECYCLING - TIME AND ENERGY

ALLOY - MIXTURE OF TWO OR MORE DIFFERENT METALS OR MIXTURE OF METAL AND NON METAL - OFEN HAVE PROPERTIES DIFFERENT FROM METALS MADE FROM - OFTEN MORE USEFUL THAN PURE METAL

STEEL - ALLOY OF IRON AND CARBON

  • HARDER AND STRONGER THAN IRON AS LONG AS CARBON NOT HIGHER THAN 1%
  • MUCH LESS LIKELY TO RUST THAN IRON 
  • USED TO MAKE BRIDGES, CUTLERY, ENGINE PARTS, SAUCEPANS ETC.
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C2C - Metals and Alloys

  • BRASS - ALLOY OF COPPER AND ZINC - HARDER THAN EITHER METALS - USED FOR BRASS INSTRUMENTS, FIXTURES AND FITTINGS E.G. SCREWS, DOORNOBS ETC.
  • BRONZE - ALLOY OF COPPER AND TIN - HARDER AND STRONGER THAN TIN - MORE RESISTANT TO CORROSION THAN BOTH METALS - USED TO MAKE SPRINGS, BELLS ETC.
  • SOLDER - ALLOY OF LEAD AND TIN - DOESN'T HAVE DEFINITE MELTING POINT BUT GRADUALLY SOLIDIFIES AS COOLS - USED FOR SOLDERING THINGS TOGETHER
  • AMALGAM - ALLOY CONTAING MERCURY - USED FOR FILLING TEETH

NITINOL - NAME GIVEN TO ALLOYS OF NICKEL AND TITANIUM THAT HAVE SHAPE MEMORY

  • GO BACK TO ORIGIONAL SHAPE AFTER BEING BENT AND TWISTED - USED FOR GLASSES WHICH ARE LESS LIKELY TO BREAK IF BENT/SAT ON ETC.
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C2D - Making Cars

RUSTING - CORROSION OF IRON - OXIDATION REACTION

  • ONLY HAPPENS WHEN IRON'S IN CONTACT WITH BOTH OXYGEN AND WATER
  • IRON GAINS OXYGEN TO FORM IRON (III) OXIDE - WATER BECOMES LOOSLY BONDED TO IRON (III) OXIDE TO FORM HYDRATED IRON (III) OXIDE - RUST
  • IRON + OXYGEN + WATER ---> HYDRATED IRON (III) OXIDE
  • RUST SOON FLAKES OFF - LEAVES MORE IRON AVAILABLE TO RUST AGAIN
  • RUSTING QUICKER IF WATER SALTY OR ACIDIC - CARS IN COASTAL PLACES RUST QUICKLY - SALTY SEA SPRAY - CARS IN DRY PLACES BARELY RUST

CORROSION OF ALUMINIUM - DOESN'T CORRODE

  • MORE REACTIVE THAN IRON - DOESN'T CORRODE - REACTS VERY QUICKLY WITH OXYGEN IN AIR - FORMS ALUMINIUM OXIDE
  • PROTECTIVE ALUMINIUM OXIDE LAYER FORMS PROTECTIVE LAYER - STICKS FIRMLY TO ALUMINIUM - STOPS FURTHER REACTIONS TAKING PLACE - NOT CRUMBLY LIKE RUST - WON'T FALL OFF
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C2D - Making Cars

CAR BODIES - ALUMINIUM OR STEEL? - ALUMINIUM HAS TWO ADVANTAGES:

  • MUCH LOWER DENSITY - CAR BODY LIGHTER - BETTER FUEL ECONOMY - SAVES FUEL RECOURCES
  • CORRODES LESS - LONGER LIFETIME
  • DISADVANTAGE - A LOT MORE EXPENSIVE - CAR MANUFACTURERS BUILD CARS OUT OF STEEL

BUILDING CARS - VARIOUS MATERIALS NEEDED:

  • STEEL - STRONG, CAN BE HAMMERED INTO SHEETS, WELDED TOGETHER - BODYWORK
  • ALUMINIUM - STRONG, LOW DENSITY - PARTS OF ENGINE (REDUCE WEIGHT)
  • GLASS - TRANSPARENT - WINDOWS AND WINDSCREENS
  • PLASTICS - LIGHT, HARDWEARING, ELECTRICAL INSULATORS - INTERIOR COVERS (DASHBOARD ETC.), WIRING
  • FIBRES - HARD WEARING - COVER SEATS AND FLOORS

RECYCLING CARS - SAVES NATURAL RECOURCES, SAVES MONEY, REDUCES LANDFILL USE

  • ONLY METAL RECYCLED - REST PUT INTO LANDFILL - 85% OF CAR NEEDS TO BE RECYCLABLE BY LAW
  • PROBLEM - NON METAL PARTS NEED TO BE SEPERATED BEFORE RECYCLED - EFFORT
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C2E - Manufacturing Chemicals - Making Ammonia

THE HABER PROCESS - REVERSABLE REACTION

  • N2 + 3H2 <---> 2NH3
  • NITROGEN OBBTAINED FROM AIR - HYDROGEN FROM CRACKING OF OIL FRACTIONS OR NATURAL GAS
  • REACTION REVERSABLE - NOT ALL N2 AND H2 CONVERTS TO AMMONIA - RECYCLED - NON WASTED
  • INDUSTRIAL CONDITIONS - HIGH PRESSURE (200 ATMOSPHERES) - HIGH TEMP (450) - IRON CATALYST

COMPROMISING CONDITIONS - CONDITIONS COMPROMISED TO ENSURE BEST ECONOMY

  • HIGHER PRESSURES - FAVOUR FORWARD REACTION - INCREASE PERCENTAGE YEIILD OF AMMONIA
  • HIGH TEMPERATURES - FAVOUR REVERSE REACTION - DECREASES PERCENTAGE YEILD OF AMMONIA
  • LOWER TEMPERATURES MEAN SLOW REACTION RATES - MANUFACTURERS USE HIGH TEMPS TO SPEED UP
  • 450 DEGREES - OPTIMUM TEMPERATURE - FAST REACTION RATE AND RESONABLE PERCENTAGE YEILD
  • UNUSED N2 AND H2 RECYCLED AND USED AGAIN - NOTHING WASTED

IRON CATALYST - SPEEDS UP REACTION AND KEEPS COSTS DOWN

  • MAKES REACTION FASTER - EQUILIBRIUM PROPORTIONS MORE QUICKLY - CATALYST DOESN'T AFFECT EQILI.
  • NO CATALYST - TEMP NEED TO BE RAISED FURTHER - REDUCE PERCENTAGE YEILD
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C2E - Manufacturing Chemicals - Making Ammonia

MINIMISING PRODUCTION COST - DEPENDS ON FIVE MAIN THINGS:

  • PRICE OF ENERGY - INDUSTRY NEEDS TO KEEP BILLS AS LOW AS POSSIBLE
    • IF REACTION NEEDS HIGH TEMPERATURE, COSTS HIGHER
  • COST OF RAW MATERIALS - KEPT AT MINIMUM BY RECYCLING UNREACTED MATERIALS
    • E.G. HABER PROCESS - PERCENTAGE YEILD LOW, UNREACTED H2 AND N2 RECYCLED
  • LABOUR COSTS - LABOUR INTENSIVE PROCESSES CAN BE EXPENSIVE
    • AUTOMATION CUTS RUNNING COSTS - NUMBER OF PEOPLE INVOLVED
    • COMPANIES NEED TO WEIGH SAVINGS ON WEDGE BILL AGAINST INITIAL AND RUNNING MACHINERY COSTS
  • PLANT COSTS - DEPENDS ON CONDITIONS EQUIPMENT NEEDS TO COPE WITH
    • E.G. COST MORE TO MAKE SOMETHING TO WITHSTAND HIGH PRESSURES
  • RATE OF PRODUCTION - FASTER REACTION, MORE COSTS REDUCED
    • RATES INCREASED USING CATALYSTS
    • PRODUCTION RATES BALANCED WITH COSTS OF BUYING CATALYST AND REPLACING ANY LOST

OPTIMUM CONDITIONS - CONDITIONS THAT GIVE THE LOWEST PRODUCTION COST

  • RATE OF REACTION AND PERCENTAGE YEILD NEED TO BE HIGH ENOUGH TO MAKE SUFFICIENT AMOUNT
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C2F - Acids and Bases

PH SCALE - GOES FROM 1 TO 14 - 1 IS ACIDIC - 14 IS ALKALINE - 7 IS NEUTREL (PURE WATER)

UNIVERSAL INDICATOR - DYE THAT CHANGES COLOUR DEPENDING ON PH OF SUBSTANCE ITS ADDED TO

  • COMBINATIONS OF DYES - CHANGES COLOUR GRADUALLY AS PH CHANGES
  • ESTIMATE PH OF SOLUTION - ADD DROP AND COMPARE IT TO COLOUR CHART
  • SOME INDICATORS CHANGE COLOUR SUDDENLY AT CERTAIN PH \

LITMUS PAPER - INDICATOR OF PH

  • BLUE PAPER - TURNS RED IN ACID, STAYS BLUE IN NEUTREL OR ALKALI
  • RED PAPER - STAYS RED IN ACID OR NEUTREL, GOES BLUE IN ALKALI

ACID - SUBSTANCE WITH PH LESS THAN 7 - FORM H+ IONS IN WATER - PH OF ACID DETERMINED BY CONCENTRATION OF H+ IONS

BASE - SUBSTANCE WITH PH GREATER THAN 7 

ALKALI - BASE THATS INSOLUBLE IN WATER - FORM OH- IONS IN WATER

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C2F - Acids and Bases

NEUTRELISATION - REACTION BETWEEN ACID AND BASE

  • ACID + BASE ---> SALT + WATER
  • H+     +  OH-  <--->    H2O

METAL OXIDES AND METAL HYDROXIDE REACTIONS

  • ACID + METAL OXIDE ---> SALT + WATER
  • ACID + METAL HYDROXIDE ---> SALT + WATER
  • HYDROCHLORIC ACID + COPPER OXIDE ---> COPPER CHLORIDE + WATER
  • 2HCL + CuO ---> CuCl2 + H2O
  • SULPHURIC ACID + POTASSIUM HYDROXIDE ---> POTASSIUM SULPHATE + WATER
  • H2SO4 + 2KOH ---> K2SO4 + 2H20
  • NITRIC ACID + SODIUM HYDROXIDE ---> SODIUM NITRATE + WATER
  • HNO2 + NaOH ---> NaNO3 + H20
  • PHOSPHORIC ACID + SODIUM HYDROXIDE ---> SODIUM PHOSPHATE + WATER
  • H3PO4 + 3NaOH ---> Na3PO4 + 3H20
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C2F - Acids and Bases

ACID AND CARBONATE REACTIONS - ACID + CARBONATE ---> SALT + WATER + CARBONDIOXIDE

  • HYDROCHLORIC ACID + SODIUM CARBONATE ---> SODIUM CHLORIDE + CARBON DIOXIDE + WATER
  • 2HCL + Na2CO3 ---> 2NaCl + CO2 + H2O
  • SULFURIC ACID + CALCIUM CARBONATE ---> CALCIUM SULPHATE + CARBON DIOXIDE + WATER
  • H2SO4 + CaCO3 ---> CaSO4 + CO2 + H2O
  • PHOSPHORIC ACID + SODIUM CARBONATE ---> SODIUM PHOSPHATE + CARBON DIOXIDE + WATER
  • 2H3PO4 + 3Na2CO3 ---> 2Na3PO4 + CO2 + H2O

ACID AND AMMONIA REACTIONS - ACID + AMMONIA ---> AMMONIUM SALT

  • HYDROCHLORIC ACID + AMMONIA ---> AMONIUM CHLORIDE
  • HCl + NH3 ---> NH4Cl
  • SULPHURIC ACID + AMMONIA ---> AMMONIUM SULFATE
  • H2SO4 + 2NH3 ---> (NH4)2SO4
  • NITRIC ACID + AMMONIA ---> AMMONIUM NITRATE
  • HNO3 + NH3 ---> NH4NO3

 

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C2G - Fertilisers and Crop Yields

FERTILISERS - CHEMICALS WHICH PROVIDE PLANTS WITH ESSENTIAL ELEMENTS FOR GROWTH

  • NIROGEN, PHOSPHORUS AND POTASSIUM - PLANTS GROWTH AND LIFE PROCESSES AFFECTED IF LACKING
  • MAY BE MISSING FROM SOIL IF USED UP BY PREVIOUS CROP - FERTILISERS REPLACE MISSING ELEMENTS OR PROVIDE MORE OF THEM - ICREASES CROP YEILD - PLANTS GROW FASTER AND BIGGER
  • MUST DISSOLVE IN WATER BEFORE TAKEN IN BY CROP ROOTS

NEUTRILISING AMMONIA

  • AMMONIA - BASE WHICH CAN BE NEUTRILISED BY ACIDS TO MAKE AMMONIUM SALTS - KEY INGREDIENT IN MANY FERTILISERS (IMPORTANT IN FOOD PRODUCTION)
  • AMMONIA PRODUCTS USED AS FERTILISERS:
    • AMONIUM NOTRATE - NEUTRILISE NITRIC ACID WITH AMMONIA - GOOD FOR FERTILISER - NITROGEN FROM TWO SOURCES (AMMONIA AND NITRIC ACID) - DOUBLE DOSE
    • AMMONIUM SULPHATE - MADE BY NEUTRILISING SULFURIC ACID WITH AMMONIA
    • AMMONIUM PHOSPHATE - MADE BY NEUTRILISING PHOSPHURIC ACID WITH AMMONIA
    • POTASSIUM NITRATE - MADE BY NEUTRILISING NITRIC ACID WITH POTASSIUM HYDROXIDE
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C2G - Fertilisers and Crop Yields

EUTROPHICATION - WHEN FERTILISERS RUNS OFF FIELDS INTO RIVERS AND LAKES

  • LEVEL OF NITRATES AND PHOSPHATES IN WATER INCREASES
  • ALGAE LIVING IN RIVER WATER USE NUTRIENTS TO MULTIPLY RAPIDLY CREATING ALGAL BLOOM - BLOCKS OFF LIGHT TO PLANTS BELOW - CANNOT PHOTOSYNTHESISE - HAVE NO FOOD AND DIE
  • AEROBIC BACTERIA THAT FEED ON DEAD PLANTS START TO MULTIPLY - USE UP ALL OXYGEN IN WATER - EVERYTHING IN RIVER DIES

PERCENTAGE YEILD - COMPARES ACTUAL YEILD TO PREDICTED YEILD

  • YIELD - MASS OF PRODUCT YOU END UP WITH AFTER REACTION
  • ALWAYS MORE THAN 0% AND LESS THAN 100%
  • 100% YEILD MEANS ALL EXPECTED YEILD IS GOT
  • 0 % YIELD - NO REACTANT CONVERTED INTO PRODUCT - NO PRODUCT MADE
  • PREDICTED YEILD OF REACTION - AMOUNT OF PRODUCT YOU WOULD GET IF ALL THE REACTANT TURNED INTO PRODUCT
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C2G - Fertilisers and Crop Yields

AMMONIUM NITRATE

  • COMMOLY USED AS FERTILISER
  • MOST FERTILISERS MADE USING TITRATION METHOD - CHOOSE RIGHT ACID AND ALKALI TO GET SALT NEEDED
  • AMMONIUM NOTRATE NEEDS AMMONIA AND NITRIC ACID:
    • SET UP APPARATUS - ADD METHYL ORANGE INDICATOR TO AMMONIA - TURN YELLOW
    • SLOWLY ADD NITRIC ACID FROM BURETTE INTO AMMONIA UNTIL YELLOW COLOUR JUST CHANGES RED - SWIRL FLASK AS ACID ADDED - GO ESPECIALLY SLOWLY WHEN ACID ALMOST NEUTRELISED
    • METHYL ACID IS YELOW IN ALKALIS, RED IN ACID - COLOUR CHANGE MEANS ALL AMMONIA NEUTRELISED - AMMONIUM NITRATE SOLUTION FORMED
    • EVAPORATE SOLUTION UNTIL ONLY A BIT LEFT - LEAVE TO CRYSTALLISE
    • AMMONIUM NITRATE CRYSTALS AREN'T PURE - STILL GOT METHYLL ORANGE IN THEM 
    • TO GET PURE AMMONIUM NITRATE, NEED TO KNOW EXACTLY HOW MUCH NITRIC ACID IT TOOK TO NEUTRELISED AMMONIA - REPEAT TITRATION USING THAT VOLUME OF ACID - NO INDICATOR
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C2H - The Chemistry of Sodium Nitrate

MINING SALT

  • EXTRACTED FROM UNDERGROUND DEPOSITS LEFT M OF YEARS AGO WHEN ANCIENT SEAS EVAPORATED
  • ROCK SALT - MIXTURE OF SALT AND IMPURITIES - DRILLED, BLASTED AND DUG OUT - BOUGHT TO SURFACE BY MACHINERY
  • SOLUTION MINING - MINED BY PUMPING HOT WATER UNDERGROUND - SALT DISSOLVES AND FORCED TO SURFACE BY PRESSURE OF WATER
  • SUBSIDENCE - UNFILLED HOLES FROM MINING CAUSE GROUND TO COLLAPSE AND SLIDE INTO HOLES - REASON WHY IMPORTANT TO FILL HOLES IN AFTER MINING
  • ROCK SALT - CAN BE USED IN RAW STATE ON ROADS - STOP ICE FORMING
  • CAN BE SEPARATED OUT - USED FOR PRESERVING AND FLAVOURING FOOD, MAKING CHEMICALS

 

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C2H - The Chemistry of Sodium Nitrate

ELECTROLYSIS OF BRINE (SODIUM CHLORIDE SOLUTION)

  • CONCENTRATED BRINE ELECTROLYSED INDUSTRIALLY
  • (http://fb.ru/misc/i/gallery/18164/353447.jpg?1394809293045)
  • ELECTRODES MADE FROM INERT MATERIAL - WON'T REACT WITH ELECTROLYTE OR PRODUCTS OF ELECTROLYSIS
  • THREE USEFUL PRODUCTS:
    • HYDROGEN GAS - GIVEN OFF AT NEGATIVE CATHOSE
    • CHLORINE GAS - GIVEN OFF AT POSITIVE ANODE
    • SODIUM HYDROXIDE - FORMED FROM IONS LEFT IN SOLUTION
  • HALF EQUATIONS:
    • CATHODE - TWO HYDROGEN IONS BOND TO BECOME H2 MOLECULE - OXIDATION         2H+ + 2e- --> H2  
    • ANODE - TWO CHLORIDE IONS BOND TO BECOME CL MOLECULE - REDUCTION              2Cl- - 2e- --> Cl2
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C2H - The Chemistry of Sodium Nitrate

USES OF PRODUCTS OF CHLOR-ALKALI PROCESS

  • HYDROGEN GAS - USED TO MAKE AMMONIA AND MARGERINE
  • CHLORINE - DISINFECT WATER, MAKE PLASTICS, SOLVENTS, HYDROCHLORIC ACID
  • SODIUM HYDROXIDE - USED TO MAKE SOAP OR REACTED WITH CHLORINE TO MAKE HOUSEHOLD BLEACH

ECONOMIC IMPORTANCE OF CHLOR-ALKALI INDISTRY

  • NEW PRODUCTS MADE AND SOLD
  • NEW JOBS CREATED FROM HELPING MANUFACTURE PRODUCTS
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