C3 - Chemical Economics

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

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

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

INTERPRETING DATA ON REACTION RATES

• 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

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

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

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

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%

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

• 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

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

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

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

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

PROPERTIES OF DIAMOND

• 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

PROPERTIES OF GRAPHITE

• 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

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

• 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
• NANOTUBES - HUGE SURFACE AREA - MAKE GOOD INDUSTRIAL CATALYSTS - INDIVIDUAL CATALYST MOLECULES COULD BE ATTATCHED TO NANOTUBE