Presentation on theme: "Unit 3 – Sections B, C & D Petroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum."— Presentation transcript:
1Unit 3 – Sections B, C & DPetroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum
2HW 1Read and take notes on B.1 & B.2 (starting on pg. 238)
3B.1 Energy and Fossil Fuels Fossils fuels originated from organic compounds plants & animals. These organisms originally captured energy from the sun via photosynthesis.Fossil fuels - crude oil, natural gas and coal are buried potential energy.
4B.1 Energy and Fossil Fuels (continued) Potential energy is the energy of position (or condition).Energy related to motion is kinetic energy.
5B.1 Energy and Fossil Fuels (continued) In a similar manner, chemical energy is a form of potential energy, is stored within chemical bonds in chemical compoundsAll of the above are examples of chemical energy !
6B.1 Energy and Fossil Fuels (continued) CH4 + 2 O2 CO2 + 2 H2O + energyThe above reaction produces considerable thermal energy (heat).
7B.1 Energy and Fossil Fuels (continued) CH4 + 2 O2 CO2 + 2 H2O + energyThink of the above as a two step process.Step 1 CH4 + 2 O2 C + 4H + 4OAll bond-breaking steps are energy requiring processes called endothermic changes.
8B.1 Energy and Fossil Fuels (continued) Step 1 CH4 + 2 O2 C + 4H + 4OIn an endothermic change energy must be added to “pull apart” the atoms in each molecule.
9B.1 Energy and Fossil Fuels (continued) Step 2 C + 4 H + 4 O CO2 + 2 H2O + ENERGYThe formation of chemical bonds is an energy-releasing process called an exothermic changes, because energy is given off.
10B.1 Energy and Fossil Fuels (continued) Step 1 CH4 + 2 O2 + energy C + 4 H + 4 OBottom line: MORE energy is given off in step 2 than is taken in for step 1.Step 2 C + 4 H + 4 O CO2 + 2 H2O + ENERGYThe overall change is exothermic.
11B.1 Energy and Fossil Fuels (continued) Pick up hereIf MORE energy has to be added than is given off the reaction is endothermic.
12B.1 Energy and Fossil Fuels (continued) In general, if a process converts potential energy into kinetic energy ... then the reverse process...converts kinetic energy back into potential energy.
13B.1 Energy and Fossil Fuels (continued) Likewise, if a chemical reaction is exothermic (releases heat)...then the reverse process...is endothermic (converts thermal energy into potential energy.)
14B.2 Energy ConversionEnergy can change form from chemical to thermal to mechanical to electrical.The law of conservation of energy states that energy is neither created nor destroyed in any mechanical, physical or chemical process.
17B.4 Energy EfficiencyAs you car owners have no doubt noticed gasoline (petroleum products) are expensive.And still going up – average cost of 1 gallon of regular (3/26/12) = $3.918
18B.4 Energy Efficiency (continued) Unfortunately devices which convert chemical energy thermal mechanical energy are typically less than 50% efficient
19B.4 Energy Efficiency (continued) Typical automobile in using 100 units of energy will:Lose :33 units through exhaust3 units to piston friction6 units pumping combustion air4 units other engine friction29 units cylinder coolingUse :25 units for horsepower
20HW Before Class Work 2Answer questions in B on pg 245, making certain to show all work AND ESPECIALLY CONVERSION FACTORS
21B.5 Example (How problems should be set up!) Assume my automobile averages miles per gallon and travels 15,000. miles per year.How much fuel will be burned in one year?If gasoline is $3.87 per gallon what will I spent in one year?=XANSWER:=XANSWER:21
22B.5 Energy Conversion Efficiency 1. Assume an automobile averages 23.0 miles per gallon and travels 11,000 miles per year.How much fuel will be burned in one year?If gasoline is $3.00 per gallon what would be spent in one year?1 gallon23.0 miles478 gallons1 year11,000 miles1 year=XANSWER: 478 gallons/yr$3.001 gallon$14341 year478 gallons1 year=XANSWER: $1434/yr
23B.5 Energy Conversion Efficiency (continued) 2. Hybrid-automobile averages 50.0 miles per gallon and travels 11,000 miles per year.How much fuel will be burned in one year?If gasoline is $3.00 per gallon what would be spent in one year?1 gallon50.0 miles220 gallons1 year11,000 miles1 year=XANSWER: 220 gallons/yr$3.001 gallon$6601 year220 gallons1 year=XANSWER: $660/yr
24B.5 Energy Conversion Efficiency (continued) 3. Q1 automobile uses only 25% of the gasoline’s energy.How much fuel is wasted each year due to inefficiency?At $3.00 per gallon , how much $?359 gallons1 year478 gallons1 year0.75=XANSWER: 359 gallons/yr WASTED$3.001 gallon$10771 year359 gallons1 year=XANSWER: $1077/yr WASTED
25B.5 Energy Conversion Efficiency (continued) 4. New car gets 70.0 mile /gallon with a 40% efficient engine.How much fuel is saved per year versus car 1 and 2?How much fuel & $ is wasted?1 gallon70 miles157 miles1 year11,000 miles1 year=XANSWER: Car gallon/yr – 157 gallon/yr = 321 g/yrCar gallon/yr – 157 gallon/yr = 63 g/yr94 gallons1 year157 gallons1 year0.60=XANSWER: 359 gallons/yr X $3.00 gallon = $283 WASTED
265 point Quiz (Remember how problems should be set up!) Assume my new hybrid automobile averages 51 miles per gallon and travels 14,500. miles per year.How much fuel will be burned in one year?If gasoline is $3.96 per gallon what will I spent in one year?=XANSWER:=XANSWER:26
28B.6 Combustion (continued) Questions ? Characteristic property of material is the amount of heat it takes to raise the temperature of 1 g of material 1°C This is called the specific heat capacity of the material.
29HWRead and take notes on B.7 starting on pg. 251
30B.7 Using Heats of Combustion With enough O2 and complete combustion the burning of a hydrocarbon is expressed as follows:Hydrocarbon + oxygen gas carbon dioxide + water + thermal energyThermal energy is a product because it is produced by the reaction.Ethane C2H6
31B.7 Using Heats of Combustion (continued) To complete this equation, the CORRECT quantity of thermal energy involved must be included2 C2H6 + 7 O2 4 CO2 + 6 H20 + ? thermal energyPer the table 3.6 on page 250 ethane releases kj/Mol2 C2H6 + 7 O2 4 CO2 + 6 H kj
32B.7 Using Heats of Combustion (continued) Sample: How much thermal energy would be produced by burning 12.0 g octane, C8H18?47.8 kj1 g octane574 kj12.0 g octane=X
33ClassworkClass work B.8 on pg 252 – Questions 1 a.-d.,2 a. & 3 a.-d. - show work and especially conversion factors
34B.8 Heats of Combustion1. Write chemical equations including thermal energy for :propaneButaneoctaneC3H O2 3 CO2 + 4 H kj2 C4H O2 8 CO H kj2 C8H O2 16 CO H kj
35B.8 Heats of Combustion (continued) 1. Write chemical equations including thermal energy for : (continued)decane2 C10H O2 20 CO H kj
36B.8 Heats of Combustion (continued) 2. a. How much thermal energy is produced burning 2 Mol of octane?5450 kj1 Mol octane=10,900 kj2 Mol octaneXANSWER: 10,900 kj produced
37B.8 Heats of Combustion (continued) 3.Write a chemical equation for burning coal including the thermal energy.C (s) + O2 CO kj
38B.8 Heats of Combustion (continued) 3.Gram for gram which is the better fuel carbon or octane? Explain your answer using calculations.Octane releases 47.8 kJ/g (Table 3.6 on pg 250)Burning coal releases1 Mol C12.01 g C394 kj1 Mol C32.8 kj/Mol=XOctane is better on a mass basis.
39B.8 Heats of Combustion (continued) 2. b. How much thermal energy is produced burning 1 gallon of octane?5450 kj1 Mol octane=10,900 kj2 Mol octaneXANSWER: 10,900 kj produced
49C.1 Creating New Options: Petrochemicals (continued) It takes few builder molecules to make many new substances. Ethene C2H4 is an example of a simple builder molecule.The arrangement of electrons is called a double covalent bond – the carbons are sharing two pair of electrons.
50C.1 Creating New Options: Petrochemicals (continued) As the double bonds have a high reactivity they are easily transformed.AcidcatalystEthenewaterEthenolThe water molecule “adds” to the double-bonded carbons – this type of reaction is called an addition reaction.
51C.1 Creating New Options: Petrochemicals (continued) Polymers formed by reactions such as this are called addition polymersAcidcatalystEthenewaterEthenolPolyethene is an example which is commonly used in grocery store bags.
52HWNotes on section C.2 Polymer Structure & Properties & C.3 Beyond Alkanes on pgs52
53C.2 Polymer Structure & Properties While unmodified polymer molecules coil loosely. Liquid polymer is intertwined like spaghetti.In this form it is flexible and soft.
54C.2 Polymer Structure & Properties (continued) For polymers, ductility means the ability to be drawn out into thin strands.While warm it is flexible – when cool more rigid.
55C.2 Polymer Structure & Properties (continued) Polymers can be enhanced by adding molecules that act as internal lubricants.Add lubricant and the material becomes flexible.
56C.2 Polymer Structure & Properties (continued) Added molecules acting as lubricants may form side chains off the main polymer chain.They are called branched polymers.
57C.2 Polymer Structure & Properties (continued) If we are trying to design a more rigid molecule we may not want them to move or slide as easily. This is done through cross linking.
58C.3 Beyond AlkanesFrom section A we learned each carbon in an alkane is bonded to 4 other atoms.Alkanes are called saturated hydrocarbons because each carbon forms as many single covelent bonds as it can.
59C.3 Beyond Alkanes (continued) In some hydrocarbon molecules, carbons only bond to THREE other atoms, not four – these are called alkenes.The carbon-carbon bonding that characterizes alkenes is a double covalent bond.
60C.3 Beyond Alkanes (continued) Alkenes which contain carbon-carbon double bonds are described as unsaturated hydrocarbons.Not all carbon atoms are bonded to their full capacity.Because of their double bonds they are more chemically reactive than alkanes.
61C.3 Beyond Alkanes (continued) Unsaturated hydrocarbons are better builder molecules than alkanes.
62C.3 Beyond Alkanes (continued) The substituted alkenes are another class of builder molecules.These molecules contain one or more of other atoms such as O, N, Cl, or S. These additions significantly change the chemical reactivity.
63C.4 The Builders (pg )On a lined piece of paper answer questions:23 (all)4 a5678910 (nothing to write)111213 (nothing to write)14
64HW on C.5 & C.6Notes on C.5 More Builder Molecules pg 270 & C.6 Builder Molecules Containing Oxygen pg 27264
65C.5 More Builder Molecules The cycloalkanes are another class of molecules which are made up of carbon atoms joined in rings.
66C.6 Builder Molecules Containing Oxygen Organic compounds are classified in functional groups most often based on properties and characteristics
67C.6 Builder Molecules Containing Oxygen (continued) Member of the alcohol group all contain an –OH.67
68C.6 Builder Molecules Containing Oxygen (continued) Member of the carboxylic acid and ester group all contain a =O and a –O bonded to the same carbon atom.68
70Notes on section D.1 and preview D.2 pgs 282 & 283 After Section C QuizNotes on section D.1 and preview D.2 pgs 282 & 28370
71D.1 Energy: Past and Present The sun is our primary energy source for the entire planet Earth.
72D.1 Energy: Past and Present (continued) Green plants using photosynthesis convert radiant energy and store it as chemical potential energy.Animals ingest plants and use that chemical energy to form other organic molecules.
73D.1 Energy: Past and Present (continued) Solar energy and energy stored in biomolecules are key energy sources for life on Earth.
74D.1 Energy: Past and Present (continued) Humans use of this stored energy is so important that the forms, availability and cost greatly influence where we live.
75D.1 Energy: Past and Present (continued) Within the U.S., until about 1850 , wood, water, wind and animal energy met our energy needs.
76D.1 Energy: Past and Present (continued) Due to the industrial revolution and increasing population demands our primary fuel source changed we became dependant on oil & coal.
77D.2 Fuel Sources over the Years Answer all questions 1-4 on pg , remember complete sentences for complete credit.
80D.3 Alternative Fuel and Energy Sources Due to the U.S. being a mobile society, U.S. oil consumption is increasing.70% of the oil consumed in the U.S. goes for transportation.
81D.3 Alternative Fuel and Energy Sources What alternatives might science offer?Alternative Energies
82D.3 Alternative Fuel and Energy Sources (continued) Oil shale is rocks which contain kerogen, partial formed oil. When processed with heat the kerogen decomposes into material similar to crude oilProConMajor deposits located west of Rocky MountainsHuge quantities of sand and rock need to be processedCurrent extraction methods are inefficientEnormous amounts of water are needed for processing
83D.3 Alternative Fuel and Energy Sources (continued) Coal liquefaction is the technology of turning coal to a liquid fuel.ProConU.S. coal reserves are much greater than U.S. oil reserves.Current cost of mining and converting is far higher than simply producing the same amount of oil(COST TOO HIGH)
84D.3 Alternative Fuel and Energy Sources (continued) Biodiesel is using technology to convert plant or animal fat into diesel liquid fuel.ProConAny source of plant or animal fat can be converted.Producing Biofuels Use More Energy than They Can Generateenergy content of biodiesel is 11% less than that of petroleum based diesel
85D.3 Alternative Fuel and Energy Sources (continued) hydropower is power that is derived from the force or energy of moving water.ProConEnvironmentally cleanpotential is limited globally to about 5 to 10% of energy needsInexpensivedependability is an issue; think prolonged droughts
86D.3 Alternative Fuel and Energy Sources (continued) Wind power is power that is derived from the force or energy of moving air.ProConEnvironmentally cleanTechnology susceptible to damage from weather eventsInexpensive!!!wind resource needs to be at over ten mph for long periods of time
87D.3 Alternative Fuel and Energy Sources (continued) Biomass Plant in TexasBurning Biomass is electricity derived from burning organic matter, particularly wood.ProCona completely renewable resourceStill producing greenhouse gasseslead to lower atmospheric greenhouse gas levelsExpensive to collect, harvest and store raw materials
88D.3 Alternative Fuel and Energy Sources (continued) Geothermal energy taps into the vast stores of natural heat within the Earth.Geothermal Plant in IcelandProConnearly completely non-pollutinghydrothermal hot spots don’t occur everywhererelatively inexpensive to operateeconomically usable sites are few
89D.6 Alternative-Fuel Vehicles Personal vehicles account for 50% of U.S. petroleum consumption.
90D.6 Alternative-Fuel Vehicles (continued) What are the alternatives?
91D.6 Alternative-Fuel Vehicles (continued) Compressed Natural gas vehicles run on methane (CH4) rather than gasoline or diesel.ProConFuel widely availableincreased vehicle cost (refueling system)Less pollution than gasoline enginesHigher fire risk danger resulting from collisions
92D.6 Alternative-Fuel Vehicles (continued) Fuel cell vehicles run on electricity generated to power the vehicle.Based on the following reaction:2 H2 + O2 2 H2O + electrical energy (and some thermal)ProConMore efficient than internal-combustion enginesfuel handlingEnvironmentally cleanFuel-cell manufacturing costs
93D.6 Alternative-Fuel Vehicles (continued) Hybrid vehicles run on gasoline-burning engine as well as a battery-powered electric motor.Captures . . .Kinetic energy and stores it as chemical potential energy.ProConGreater mpg, typically over 40 & can travel more than 650 mile between fuel stopStill emit greenhouse gasses
94D.5 Biodiesel as a Petroleum Substitute Fun with numbers – questions 1-3 on pg 288 , please show all your work