C3 - Chemical Economics

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C3A - Rate of Reaction (1)

DIFFERENT REACTION RATES

SLOW REACTIONS - RUSTING OF IRON, CHEMICAL WEATHERING
MODERATE SPEED REACTONS - METAL REACTING WITHDILUTE ACID - PRODUCE GENTLE STREAM BUBBLES
FAST REACTIONS - BURNING, EXPLOSIONS

EXPERIMENT TO FOLLOW A REACTION

MEASURING CHANGE IN MASS - CARRY OUT REACTION ON A BALANCE - MASS OF FLASK WILL FALL AS GAS IS RELEASED - TAKE READINGS OF MASS AT REGULAR TIME INTERVALS - USES FLASK, BUNSEN BURNER, TIMER
MEASURING VOLUME OF GAS GIVEN OFF - USE GAS SYRINGE TO MEASURE VOLUME OF GAS GIVEN OFF AFTER REGULAR TIME INTERVALS

STOPPING OF REACTIONS

YEILD OF REACTION DEPENDS ON AMOUNT OF REACTANT STARTED WITH - MORE REACTANT MEANS MORE PARTICALS - HAVE MORE REACTIONS - CREATE MORE PRODUCT
AMOUNT OF PRODUCT DIRECTLY PROPORTIONAL TO AMOUNT OF LIMITING REACTANT (REACTANT THAT'S TOTALLY USED UP DURING REACTION) - REACTION STOPS WHEN ALL LIMITING REACTANT IS USED UP

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C3B - Rate of Reaction (2)

COLLISION THEORY

  • RATE OF REACTION DEPENDS ON:
  • COLLISION FREQUENCY OF PARTICLES - MORE COLLISIONS MEANS FASTER REACTIONS
  • ENERGY TRANSFERED DURING COLLISION - PARTICLES HAVE TO COLLIDE WITH ENOUGH ENERGY FOR REACTION TO BE SUCCESSFUL

INCREASING TEMPERATURE

  • PARTICLES MOVE MORE QUICKLY - COLLIDE MORE
  • INCREASES ENERGY OF COLLISIONS - MORE PARTICLES COLLIDING WITH ENOUGH ENERGY TO REACT

INCREASING CONCENTRATION

MORE PARTICLES OF REACTANT IN SAME VOLUME - MAKES COLLISION MORE LIKELY - IN GAS, HIGHER PRESSURE MEANS PARTICLES ARE MORE CROWED - FREQUENCY OF COLLISIONS INCREASES

SMALLER SOLID PARTICLES

INCREASE SURFACE AREA OF REACTANT EXPOSED TO OTHER REACTANT - MORE SPACE TO WORK ON

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C3C - Rate of Reaction (3)

CATALYSTS

  • SUBSTANCE WHICH INCREASES SPEED OF REACTION WITHOUT BEING CHEMICALLY CHANGED OR USED UP IN REACTION
  • ONLY NEED A TINY BIT OF CATALYST TO CATALYSE LARGE AMOUNTS OF REACTANTS - ISN'T USED UP
  • SPECIFIC CATALYSTS CATALYSE SPECIFIC REACTIONS - CATALYSTS AREN'T UNIVERSAL
  • WORKS BY GIVING REACTING PARTICLES A SURFACE TO STICK TO WHERE THEY CAN BUMP INTO EACHOTHER - REDUCES ENERGY NEEDED BY PARTICLES TO REACT - OVERALL NUMBER OF COLLISIONS NOT INCREASED BUT NUMBER OF SUCCESSFUL COLLISIONS IS

LUMP AND POWDERED REACTANTS

  • POWDERED REACTANT REACTS QUICKER - SMALLER PARTICLES - MORE SURFACE AREA EXPOSED TO SUBSTANCE IT'S REACTING WITH THAN A LUMP REACTANT OF SAME MASS - MORE AREA FOR REACTING SUBSTANCES TO WORK ON
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C3C - Rate of Reaction Data

INTERPRETING DATA ON REACTION RATES

(http://staff.norman.k12.ok.us/~cyohn/index_files/ratenotes_files/image002.jpg)

  • DETERMINE HOW MUCH PRODUCT IS PRODUCES WHEN REACTION FINISHES (LIMITING REACTANT USED UP) - WHERE ON AXIS LABELED 'VOLUME' LINE GOES FLAT
  • DETERMINE HOW LONG REACTION TOOK - WHERE ON AXIS LABELED 'TIME' LINE GOES FLAT
  • EXTRAPOLATION - DETERMINING VALUE THAT IS NOT VISIBLE ON GRAPH BY ASSUMING THAT GRAPH FOLLOWS LOGICALLY THE SAME PATTERN AS THE DATA THAT IS VISIBLE
  • INTERPOLATION - CONSTRUCTING NEW DATA POINTS ACCORDING TO ESTIMATE BASED ON PATERN THAT VISIBLE DATA FOLLOWS
  • COMPARING TWO REACTIONS - WHICH REACTION IS FASTER - WHICH LINE GOES FLAT FIRST, WHICH LINE IS STEEPER
  • WHEN CONCLUDING, TALK ABOUT DIRECT POINTS ON GRAPH AND LINK IT TO OWN KNOWLEDGE ON COLLISION THEORY
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C3D - Reacting Masses

REACTING MASSES

  • RELATIVE ATOMIC MASS - BIGGER NUMBER OF TWO NUMBERS FOR EACH ELEMENT - MASS OF PROTONS AND NEUTRONS IN NUCLEUS OF ELEMENT
  • RELATIVE FORMULA MASS - ALL RELATIVE ATOMIC MASSES OF INDIVIDUAL ELEMENTS IN COMPOUND ADDED TOGETHER

MASS CONSERVED

  • DURING CHEMICAL REACTION, NO ATOMS ARE DESTROYED AND NO ATOMS ARE CREATED - SAME NUMBER AND TYPES OF ATOM ON EACH SIDE OF EQUASION
  • YOU CAN SEE THAT MASS IS CONSERVED BY ADDING UP RELATIVE FORMULA MASSES ON EACH SIDE OF EQUASION
  • NEED TO BE ABLE TO BALANCE EQUASIONS

 

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C3D - Reacting Masses

CALCULATING MASSES IN REACTIONS - THREE STEPS

  • - WORK OUT BALANCED EQUASION
  • - WORK OUT RELATIVE FORMULA MASS FOR TWO BITS YOU WANT
  • - DIVIDE TO GET ONE, THEM MULTIPLY OUT TO GET ALL
  • E.G. CALCULATE MASS OF MAGNESIUM OXIDE PRODUCED WHEN 60g MAGNESIUM BURNED IN AIR
  • - BALANCED EQUASION: 2Mg +O2 ---> 2MgO
  • - RELATIVE FORMULA MASS OF MAGNESIUM - 48
  • - RELATIVE FORMULA MASS OF MAGNESIUM OXIDE PRODUCED - 80
  • 48g MAGNESIUM REACTS TO GIVE 80g OF MAGNESIUM OXIDE - DIVIDE BOTH SIDES BY 48 TO GET AMOUNT PRODUCED FOR 1g OF MAGNESIUM AND THEN MULTIPLY BY AMOUNT OF G BURNED (60) - (80 / 48) X 60 = 100g       60g MAGNESIUM REACTS TO GIVE 100G OF MAGNESIUM OXIDE
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C3E - Percentage Yield and Atom Economy

PERCENTAGE YIELD

  • PERCENTAGE YIELD = (ACTUAL YEILD (G) / PREDICTED YEILD (G)) X 100
  • PREDICTED YIELD OF A REACTION - CALCULATED BY LOOKING AT FORMULA MASSES OF BALANCED EQUASIONS
  • PERCENTAGE YEILD ALWAYS BETWEEN 0 AND 100 PERCENT - 100% MEANS ALL REACTANT WAS CONVERTED INTO PRODUCT, 0% MEANS NO REACTANT CONVERTED INTO PRODUCT
  • PERCENTAGE YEILD CAN NEVER BE 100% BECAUSE SOME REACTANT IS ALWAYS LOST THROUGH:
  • EVAPORATION - LIQUIDS CONSTANTLY EVAPORATING - EVEN MORE SO WHEN BEING HEATED
  • NOT ALL REACTANTS REACT TO MAKE PRODUCT - IN REVERSABLE REACTIONS, PRODUCTS CAN TURN BACK INTO REACTANTS - YIELD WILL NEVER BE 100%
  • FILTRATION - WHEN LIQUID IS FILTERED TO REMOVE SOLID PARTICLES, A BIT OF THE LIQUID OR SOLID IS ALWAYS LOST - IF LIQUID NEEDS TO BE KEPT, A BIT THAT REMAINS WITH SOLID AND FILTER PAPER IS LOST - IF YOU WANT TO KEEP SOLID, BITS THAT GET LEFT BEHIND WHEN SCRAPED OFF FILTER PAPER IS LOST
  • TRANSFERING LIQUIDS - ALWAYS LOSE A BIT OF LIQUID WHEN IT'S TRANSFERED FROM ONE CONTAINER TO ANOTHER - SOME BITS ALWAYS GET LEFT BEHIND ON SURFACE OF CONTAINER LIQUID IS BEING TRANSFERED FROM - ALWAYS WET WHEN FINISHED
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C3E - Percentage Yield and Atom Economy

ATOM ECONOMY

  • ATOM ECONOMY = (TOTAL FORMULA MASS OF DESIRED PRODUCTS / TOTAL FORMULA MASS OF ALL PRODUCTS) X 100
  • 100% ATOM ECONOMY MEANS THAT ALL REACTANTS HAVE BEEN TURNED INTO USEFUL PRODUCTS
  • E.G. ATOM ECONOMY OF REACTION OF METHANE AND STEAM TO GET HYDROGEN GAS
  • CH4 + H2O ---> CO + 3H2
  • - IDENTIFY USEFUL PRODUCT - HYDROGEN
  • - WORK OUT FORMULA MASS OF ALL PRODUCTS AND THEN FORMULA MASS OF ALL USEFUL PRODUCTS
  • ALL PRODUCTS = 34
  • HYDROGEN = 6
  • PUT IT INTO EQUASION - (34 / 6) X 100 = 17.6%
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C3E - Percentage Yield and Atom Economy

ECONOMIC ADVANTAGES OF HIGH ATOM ECONOMY

  • REACTIONS WITH LOW ATOM ECONOMY USE UP RECOURCES VERY QUICKLY AND MAKE A LOT OF WASTE
  • RAW MATERIALS NEEDED FOR REACTIONS ARE EXPENSIVE
  • DISPOSAL OF WASTE PRODUCTS CAN BE EXPENSIVE - NEED TO FIND A WAY TO REUSE WASTE PRODUCTS RATHER THAN JUST DISPOSING OFTHEM
  • LOW ATOM ECONOMY REACTIONS NOT PROFITABLE - HIGH ATOM ECONOMY MEANS THEY ONLY HAVE ONE PRODUCT SO MOST MONEY SPENT ON RAW MATERIALS (REACTANTS) IS NOT WASTED

ENVIRONMENTAL ADVANTAGES OF HIGH ATOM ECONOMY

  • DISPOSAL OF WASTE PRODUCTS - BAD FOR ENVIRONMENT - LANDFILL SITES WASTE SPACE - BURNING RELEASES TOXIC GASES
  • MORE RAW MATERIALS NEEDED MEANS MORE UNRENEWABLE RECOURCES BEING USED UP FOR NOT A LOT OF RESULT
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C3F - Energy

  • EXOTHERMIC REACTIONS - REACTIONS THAT GIVE OUT ENERGY TO SURROUNDINGS USUALLY IN FORM OF HEAT - SHOWN BY RISE IN TEMPERATURE
  • ENDOTHERMIC REACTIONS - REACTIONS THAT TAKE IN ENERGY FROM SURROUNDINGS USUALLY IN FORM OF HEAT - SHOWN BY FALL IN TEMPERATURE
  • EXPERIMENT - MEASURE TEMPERATURE OF INDIVIDUAL REACTANTS AND THEN MIX THEM AND MEASURE TEMPERATURE OF MIXTURE
  • ADDING ACID TO ALKALI - EXOTHERMIC REACTION - TEMPERATURE INCREASES WHEN ACID AND ALKALI MIX
  • DISSOLVING AMMONIUM NITRATE IN WATER - ENDOTHERMIC REACTION - TEMPERATURE DECREASES WHEN AMMONIUM NITRATE IS DISSOLVED

BONDS - CHEMICAL REACTION - OLD BONDS BROKEN AND NEW BONDS FORMED

  • ENERGY SUPPLIED TO BREAK BONDS - BONDS BREAKING IS ENDOTHERMIC - ENERGY RELEASED WHEN BONDS FORM - BONDS FORMING IS EXOTHERMIC
  • EXOTHERMIC REACTIONS - ENERGY RELEASED IN BONDS FORMING GREATER THAN ENERGY TAKEN IN WHEN BONDS BREAK
  • ENDOTHERMIC REACTION - ENERGY TAKEN IN WHEN BONDS BREAK IS GREATER THAN ENERGY GIVEN OUT WHEN BONDS FORM
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C3F - Energy

SPECIFIC HEAT CAPACITY

  • CALOMETRIC EXPERIMENT - INVOLVES HEATING WATER BY BURNING LIQUID FUEL
  • IF YOU MEASURE HOW MUCH FUEL YOU'VE BURNED AND THE TEMPERATURE CHANGE OF THE WATER, YOU CAN WORK OUT HOW MUCH ENERGY IS SUPPLIED FOR EACH GRAM OF FUEL
  • ALSO NEED TO KNOW SPECIFIC HEAT CAPACITY OF WATER - 4.2 J TO RAISE TEMP BY 1 DEGREE
  • DO SAME EXPERIMENT WITH DIFFERENT FUELS, COMPARE ENERGY TRANSFERRED WITH EACH FUEL - FUEL WITH HIGHER ENERGY CONTENT PER GRAM MEANS YOU NEED LESS TO RAISE TEMP BY SAME AMOUNT

METHOD

  • IMPORTANT TO REDUCE HEAT LOSS AS MUCH AS POSSIBLE - USE SCREEN TO ACT AS DRAUGH EXCLUDER
  • PUT FUEL INTO SPIRIT BURNER AND WEIGH BURNER FULL OF FUEL
  • MESURE OUT 200CM WATER INTO COPPER CALORIMETER
  • TAKE INITIAL TEMP OF WATER AND PUT BURNER UNDER CALORIMETER AND LIGHT
  • WHEN TEMP OF WATER HAS RISEN BY 20-30 DEGREES, PUT OUT SPIRIT BURNER AND MAKE NOTE OF HIGHEST TEMP THE WATER REACHES
  • REWEIGH BURNER OF FUEL
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C3F - Energy

CALCULATIONS

  • FIND OUT MASS OF FUEL BURNED BY SUBTRACTING FINAL MASS OF FUEL BURNER FROM INITIAL MASS
  • ENERGY TRANSFERED (J) = MASS OF WATER (G) X SPECIFIC HEAT CAPACITY OF WATER X TEMP CHANGE (C)
  • ENERGY GIVEN OUT PER GRAM = ENERGY RELEASED (J) / MASS OF FUEL BURNED (G)

FAIR TEST

  • TO COMPARE ENERGY CONTENT OF DIFFERENT FUELS THE SAME EXPERIEMNT NEEDS TO BE DONE SEVERAL TIMES, USING DIFFERENT FUELS EACH TIME
  • FOR COMPARISON TO BE FAIR, EVERYTHING EXCEPT FUEL USED NEEDS TO BE THE SAME
  • SAME APPERATUS SHOULD BE USED
  • SAME AMOUNT OF WATER SHOULD BE USED
  • WATER SHOULD START AND FINISH AT SAME TEMPERATURE EACH TIME
  • FOR RELIABLE RESULTS, REPEAT EXPERIMENT WITH SAME FUEL SEVERAL TIMES AND DICOUNT ANOMOLOUS RESULTS
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C3G - Batch or Continuous?

BATCH PRODUCTION

  • ONLY OPERATES AT CERTAIN TIMES - USED FOR COMPLICATED DRUGS WITH FAIRLY LOW DEMAND
  • ADVANTAGES - FLEXIBLE - SEVERAL DIFFERENT PRODUCTS CAN BE MADE USING SAME EQUIPMENT
  • START UP COSTS RELATIVELY LOW - SMALL SCALE, MULTI PURPOSE EQUIPMENT CAN BE BOUGHT OFF THE SHELF
  • DISADVANTAGES - LABOUR INTENSIVE - EQUIPMENT NEEDS TO BE SET UP MANUALLY, CONTROLLED FOR EACH BATCH AND CLEARED OUT AT END
  • CAN BE TRICKY TO KEEP SAME QUALITY FROM BATCH TO BATCH

CONTINUOUS PRODUCTION

  • RUNS ALL THE TIME - USED FOR LARGE SCALE INDUSTRIAL MANUFACTURE OF POPULAR CHEMICALS
  • ADVANTAGES - PRODUCTION NEVER STOPS - NO TIME WASTED CLEARING UP AND SETTING UP AGAIN
  • RUNS AUTOMATICALLY - NO LABOUR UNLESS SOMETHING GOES WRONG
  • QUALITY OF PRODUCT VERY CONSISTANT
  • DISADVANTAGES - START UP COSTS HUGE, NOT COST EFFECTIVE IF RUN LESS THAN FULL CAPACITY
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C3G - Batch or Continuous?

PHARMACEUTICAL DRUGS

  • COMPLICATED AND FAIRLY EXPENSIVE TO MAKE - FAIRLY LOW DEMAND - BATCH PRODUCTION MOST COST EFFECTIVE WAY - PRODUCTION HAS SEVERAL STAGES:
  • RESEARCH AND DEVELOPMENT - FINDING A SUITABLE COMPOUND, TESTING, MODIFYING, RETESTING - INVOLVES WORK OF A LOT OF HIGHLY PAID SCIENTISTS
  • TRIALLING - NO DRUG ALLOWED TO BE MANUFACTURED UNLESS IT'S BEEN TRIALED - TIME CONSUMING - ANIMAL AND HUMAN TRIALS - PROVE THAT DRUG MEETS LEGAL REQUIREMENTS AND IS SAFE
  • MANUFACTURE - MULTI STEP BATCH PRODUCTION - LABOUR INTENSIVE - CAN'T BE AUTOMATED 
  • RAW MATERIALS AND ENERGY FOR MANUFACTURE COST MONEY - RAW MATERIALS OFTEN RARE - EXTRACTED USING CERTAIN METHOD:
  • TO EXTRACT SUBSTANCE FROM PLANT, IT HAS TO BE CRUSHED, BOILED AND DISSOLVED IN SOLUBLE SOLVENT - SUBSTANCES THEN EXTRACTED BY CHROMATOGRAPHY

TESTING FOR PURITY

  • IMPURE SUBSTANCES WON'T BE SEPERATED BY CHROMATOGRAPHY
  • IMPURE SUBSTANCE - NO SPECIFIC MELT TEMPS, MELTING POINT TOO LOW AND BOILING POINT TOO HIGH
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C3H - Allotropes of Carbon and Nanochemistry

PROPERTIES OF DIAMOND

(http://www.nicediamond.com/storage/Image/Diamond%20Types/IIbAtomStructureColor.JPG)

  • LUSTROUS AND COLOURLESS - IDEAL FOR JEWELLERY
  • HARD - EACH CARBON ATOM FORMS FOUR COVALENT BONDS IN VERY RIGID, GIANT COVELENT STRUCTURE - USED FOR CUTTING TOOLS
  • VERY HIGH MELTING POINT - COVALENT BONDS TAKE A LOT OF ENERGY TO BREAK - GOOD CUTTING TOOL
  • DOESN'T CONDUCT ELECTRICITY - NO FREE ELECTRONS
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C3H - Allotropes of Carbon and Nanochemistry

PROPERTIES OF GRAPHITE

(http://www.eduys.com/photo/original_108b32da9e1f2e6743b3ffb9bb70fa77/demonstration-model-of-graphite-molecular-structure.jpg)

  • BLACK AND OPAQUE BUT STILL SHINY
  • EACT CARBON FORMS THREE COVALENT BONDS, CREATING SHEETS OF CARBON ATOMS FREE TO SLIDE OVER EACHOTHER
  • LAYERS CAN BE RUBBED OFF ONTO PAPER - LEAVES BLACK MARK - LAYERS HELD TOGETHER WEAKLY - SLIPPERY - USED IN PENCILS
  • CONDUCTS ELECTRICITY - THREE COVELENT BONDS - LOTS OF DELOCALISED ELECTRONS
  • HIGH MELTING POINT - COVALENT BONDS - A LOT OF ENERGY TO BREAK
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C3H - Allotropes of Carbon and Nanochemistry

GIANT MOLECULAR STRUCTURES

  • CARBON CAN FORM LOTS OF COVALENT BONDS WITH ITSELF - CAN FORM LOTS OF GIANT MOLECULAR STRUCTURES - DIAMOND AND GRAPHITE SHEETS
  • STRONG, HIGH MELTING POINTS, DON'T DISSOLVE IN WATER - COVALENT BONDS
  • DON'T CONDUCT ELECTRICITY - NO DELOCALISED ELECTRONS - GRAPHITE IS AN ACCEPTION

FULLERINES

  • (http://www.nanotube.msu.edu/fullerene/C180/C180-0.png)MOLECULES OF CARBON SHAPED LIKE CLOSED TUBES OR HOLLOW BALLS - NANOPARTICLES
  • CAN BE USED TO CAGE OTHER MOLECULES - FORMS AROUND ANOTHER ATOM OR MOLECULE WHICH IS THEN TRAPPED INSIDE - NEW WAY OF DELIVERING DRUG INTO BODY FOR SLOW RELEASE
  • CAN BE JOINED TOGETHER TO FORM NANOTUBES - TINY HOLLOW CARBON TUBES
  • (http://britton.disted.camosun.bc.ca/carbon_nano/nanotube-70.gif)NANOTUBES - HUGE SURFACE AREA - MAKE GOOD INDUSTRIAL CATALYSTS - INDIVIDUAL CATALYST MOLECULES COULD BE ATTATCHED TO NANOTUBE
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