Presentation on theme: "Unit 3 – Sections B, C & D Petroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum."— Presentation transcript:
Unit 3 – Sections B, C & D Petroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum
HW 1 Read and take notes on B.1 & B.2 (starting on pg. 238)
B.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.
B.1 Energy and Fossil Fuels (continued) Potential energy is the energy of position (or condition). Energy related to motion is kinetic energy.
B.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 compounds All of the above are examples of chemical energy !
B.1 Energy and Fossil Fuels (continued) CH O 2 CO H 2 O + energy The above reaction produces considerable thermal energy (heat).
B.1 Energy and Fossil Fuels (continued) CH O 2 CO H 2 O + energy Think of the above as a two step process. Step 1 CH O 2 C + 4H + 4O All bond-breaking steps are energy requiring processes called endothermic changes.
B.1 Energy and Fossil Fuels (continued) Step 1 CH O 2 C + 4H + 4O In an endothermic change energy must be added to “pull apart” the atoms in each molecule.
The formation of chemical bonds is an energy-releasing process called an exothermic changes, because energy is given off. B.1 Energy and Fossil Fuels (continued) Step 2 C + 4 H + 4 O CO H 2 O + ENERGY
B.1 Energy and Fossil Fuels (continued) Step 2 C + 4 H + 4 O CO H 2 O + ENERGY Bottom line: MORE energy is given off in step 2 than is taken in for step 1. Step 1 CH O 2 + energy C + 4 H + 4 O The overall change is exothermic.
B.1 Energy and Fossil Fuels (continued) If MORE energy has to be added than is given off the reaction is endothermic.
B.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.
B.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.)
B.2 Energy Conversion Energy 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.
B.2 Energy Conversion (continued)
HW 2 Notes from B.4
B.4 Energy Efficiency As 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
B.4 Energy Efficiency (continued) Unfortunately devices which convert chemical energy thermal mechanical energy are typically less than 50% efficient
B.4 Energy Efficiency (continued) Typical automobile in using 100 units of energy will: Lose : 33 units through exhaust 3 units to piston friction 6 units pumping combustion air 4 units other engine friction 29 units cylinder cooling Use : 25 units for horsepower
HW Before Class Work 2 Answer questions in B on pg 245, making certain to show all work AND ESPECIALLY CONVERSION FACTORS
B.5 Example (How problems should be set up!) Assume my automobile averages miles per gallon and travels 15,000. miles per year. a.How much fuel will be burned in one year? b.If gasoline is $3.87 per gallon what will I spent in one year? X = X = ANSWER:
B.5 Energy Conversion Efficiency 1. Assume an automobile averages 23.0 miles per gallon and travels 11,000 miles per year. a.How much fuel will be burned in one year? b.If gasoline is $3.00 per gallon what would be spent in one year? 11,000 miles 1 year 1 gallon 23.0 miles X = 478 gallons 1 year 478 gallons 1 year $ gallon X = $ year ANSWER: 478 gallons/yr ANSWER: $1434/yr
B.5 Energy Conversion Efficiency (continued) 2. Hybrid-automobile averages 50.0 miles per gallon and travels 11,000 miles per year. a.How much fuel will be burned in one year? b.If gasoline is $3.00 per gallon what would be spent in one year? 11,000 miles 1 year 1 gallon 50.0 miles X = 220 gallons 1 year 220 gallons 1 year $ gallon X = $660 1 year ANSWER: 220 gallons/yr ANSWER: $660/yr
B.5 Energy Conversion Efficiency (continued) 3. Q1 automobile uses only 25% of the gasoline’s energy. a.How much fuel is wasted each year due to inefficiency? b.At $3.00 per gallon, how much $? 478 gallons 1 year 0.75 X = 359 gallons 1 year 359 gallons 1 year $ gallon X = $ year ANSWER: 359 gallons/yr WASTED ANSWER: $1077/yr WASTED
B.5 Energy Conversion Efficiency (continued) 4. New car gets 70.0 mile /gallon with a 40% efficient engine. a.How much fuel is saved per year versus car 1 and 2? b.How much fuel & $ is wasted? 157 gallons 1 year 0.60 X = 94 gallons 1 year 11,000 miles 1 year 1 gallon 70 miles X = 157 miles 1 year ANSWER: 359 gallons/yr X $3.00 gallon = $283 WASTED ANSWER: Car gallon/yr – 157 gallon/yr = 321 g/yr Car gallon/yr – 157 gallon/yr = 63 g/yr
5 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. a.How much fuel will be burned in one year? b.If gasoline is $3.96 per gallon what will I spent in one year? X = X = ANSWER:
B.6 Combustion Pre-read B.6 – pg
B.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.
HW Read and take notes on B.7 starting on pg. 251
B.7 Using Heats of Combustion With enough O 2 and complete combustion the burning of a hydrocarbon is expressed as follows: Ethane C 2 H 6 Hydrocarbon + oxygen gas carbon dioxide + water + thermal energy Thermal energy is a product because it is produced by the reaction.
B.7 Using Heats of Combustion (continued) To complete this equation, the CORRECT quantity of thermal energy involved must be included 2 C 2 H O 2 4 CO H ? thermal energy Per the table 3.6 on page 250 ethane releases 1560 kj/Mol 2 C 2 H O 2 4 CO H kj
B.7 Using Heats of Combustion (continued) Sample: How much thermal energy would be produced by burning 12.0 g octane, C 8 H 18 ? 12.0 g octane 47.8 kj 1 g octane X = 574 kj
Classwork Class work B.8 on pg 252 – Questions 1 a.-d.,2 a. & 3 a.-d. - show work and especially conversion factors
B.8 Heats of Combustion 1. Write chemical equations including thermal energy for : a.propane b.Butane c.octane C 3 H O 2 3 CO H kj 2 C 4 H O 2 8 CO H kj 2 C 8 H O 2 16 CO H kj
B.8 Heats of Combustion (continued) 1. Write chemical equations including thermal energy for : (continued) d. decane 2 C 10 H O 2 20 CO H kj
B.8 Heats of Combustion (continued) 2. a. How much thermal energy is produced burning 2 Mol of octane? 2 Mol octane 5450 kj 1 Mol octane X = 10,900 kj ANSWER: 10,900 kj produced
B.8 Heats of Combustion (continued) 3.a. Write a chemical equation for burning coal including the thermal energy. C (s) + O 2 CO kj
B.8 Heats of Combustion (continued) 3.b. 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) 394 kj 1 Mol C g C X = 32.8 kj/Mol Burning coal releases Octane is better on a mass basis.
B.8 Heats of Combustion (continued) 2. b. How much thermal energy is produced burning 1 gallon of octane? 2 Mol octane 5450 kj 1 Mol octane X = 10,900 kj ANSWER: 10,900 kj produced
Quiz Tomorrow on Section B Please be prepared
HW on C.1 Notes on C.1 Creating New Options: Petrochemicals pg 262
C.1 Creating New Options: Petrochemicals Until early 1800s everything we used was made of Wood Stone Metals
C.1 Creating New Options: Petrochemicals (continued) All medicines and food additives came from natural sources.
C.1 Creating New Options: Petrochemicals (continued) At that time celluloid (wood) and shellac (animal material) were the only source for commercially produced polymers.
C.1 Creating New Options: Petrochemicals (continued) Polymers are typically large molecules, 500 to 20,000 repeating units. The single unit is known as a monomer.
C.1 Creating New Options: Petrochemicals (continued) Many of today’s polymers are created using compounds produced using oil or natural gas and they are called petrochemicals.
C.1 Creating New Options: Petrochemicals (continued) Most petrochemicals serve as raw materials producing a wide range of polymers.
It takes few builder molecules to make many new substances. Ethene C 2 H 4 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.
As the double bonds have a high reactivity they are easily transformed. The water molecule “adds” to the double- bonded carbons – this type of reaction is called an addition reaction. EthenewaterEthenol Acid catalyst
C.1 Creating New Options: Petrochemicals (continued) Polymers formed by reactions such as this are called addition polymers Polyethene is an example which is commonly used in grocery store bags. EthenewaterEthenol Acid catalyst
HW Notes on section C.2 Polymer Structure & Properties & C.3 Beyond Alkanes on pgs
C.2 Polymer Structure & Properties While unmodified polymer molecules coil loosely. Liquid polymer is intertwined like spaghetti. In this form it is flexible and soft.
C.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.
C.2 Polymer Structure & Properties (continued) Polymers can be enhanced by adding molecules that act as internal lubricants. Add lubricant and the material becomes flexible.
C.2 Polymer Structure & Properties (continued) Added molecules acting as lubricants may form side chains off the main polymer chain. They are called branched polymers.
C.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.
C.3 Beyond Alkanes From 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.
C.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.
C.3 Beyond Alkanes (continued) Alkenes which contain carbon-carbon double bonds are described as unsaturated hydrocarbons. Because of their double bonds they are more chemically reactive than alkanes. Not all carbon atoms are bonded to their full capacity.
C.3 Beyond Alkanes (continued) Unsaturated hydrocarbons are better builder molecules than alkanes.
C.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.
C.4 The Builders (pg ) On a lined piece of paper answer questions: 2 3 (all) 4 a (nothing to write) (nothing to write) 14
HW on C.5 & C.6 Notes on C.5 More Builder Molecules pg 270 & C.6 Builder Molecules Containing Oxygen pg 272
C.5 More Builder Molecules The cycloalkanes are another class of molecules which are made up of carbon atoms joined in rings.
C.6 Builder Molecules Containing Oxygen Organic compounds are classified in functional groups most often based on properties and characteristics
C.6 Builder Molecules Containing Oxygen (continued) Member of the alcohol group all contain an –OH.
C.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.
Section C Quiz Break
After Section C Quiz Notes on section D.1 and preview D.2 pgs 282 & 283
D.1 Energy: Past and Present The sun is our primary energy source for the entire planet Earth.
D.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.
D.1 Energy: Past and Present (continued) Solar energy and energy stored in biomolecules are key energy sources for life on Earth.
Humans use of this stored energy is so important that the forms, availability and cost greatly influence where we live.
Within the U.S., until about 1850, wood, water, wind and animal energy met our energy needs.
Due to the industrial revolution and increasing population demands our primary fuel source changed we became dependant on oil & coal.
D.2 Fuel Sources over the Years Answer all questions 1-4 on pg , remember complete sentences for complete credit.
D.2 Fuel Sources over the Years
HW Notes on D.3 on pgs
D.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.
What alternatives might science offer? Alternative Energies
D.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 oil ProCon Major deposits located west of Rocky Mountains Huge quantities of sand and rock need to be processed Current extraction methods are inefficient Enormous amounts of water are needed for processing
D.3 Alternative Fuel and Energy Sources (continued) Coal liquefaction is the technology of turning coal to a liquid fuel. ProCon U.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)
D.3 Alternative Fuel and Energy Sources (continued) Biodiesel is using technology to convert plant or animal fat into diesel liquid fuel. ProCon Any source of plant or animal fat can be converted. Producing Biofuels Use More Energy than They Can Generate energy content of biodiesel is 11% less than that of petroleum based diesel
D.3 Alternative Fuel and Energy Sources (continued) hydropower is power that is derived from the force or energy of moving water. ProCon Environmentally clean potential is limited globally to about 5 to 10% of energy needs Inexpensive dependability is an issue; think prolonged droughts
D.3 Alternative Fuel and Energy Sources (continued) Wind power is power that is derived from the force or energy of moving air. ProCon Environmentally clean Technology susceptible to damage from weather events Inexpensive!!! wind resource needs to be at over ten mph for long periods of time
D.3 Alternative Fuel and Energy Sources (continued) Burning Biomass is electricity derived from burning organic matter, particularly wood. ProCon a completely renewable resource Still producing greenhouse gasses lead to lower atmospheric greenhouse gas levels Expensive to collect, harvest and store raw materials Biomass Plant in Texas
D.3 Alternative Fuel and Energy Sources (continued) Geothermal energy t aps into the vast stores of natural heat within the Earth. ProCon nearly completely non-polluting hydrothermal hot spots don’t occur everywhere relatively inexpensive to operate economically usable sites are few Geothermal Plant in Iceland
D.6 Alternative-Fuel Vehicles Personal vehicles account for 50% of U.S. petroleum consumption.
D.6 Alternative-Fuel Vehicles (continued) What are the alternatives?
D.6 Alternative-Fuel Vehicles (continued) Compressed Natural gas vehicles run on methane (CH 4 ) rather than gasoline or diesel. ProCon Fuel widely available increased vehicle cost (refueling system) Less pollution than gasoline engines Higher fire risk danger resulting from collisions
D.6 Alternative-Fuel Vehicles (continued) Fuel cell v ehicles run on electricity generated to power the vehicle. ProCon More efficient than internal- combustion engines fuel handling Environmentally clean Fuel-cell manufacturing costs Based on the following reaction: 2 H 2 + O 2 2 H 2 O + electrical energy (and some thermal)
D.6 Alternative-Fuel Vehicles (continued) Hybrid vehicles run on gasoline-burning engine as well as a battery- powered electric motor. ProCon Greater mpg, typically over 40 & can travel more than 650 mile between fuel stop Still emit greenhouse gasses Captures... Kinetic energy and stores it as chemical potential energy.
D.5 Biodiesel as a Petroleum Substitute Fun with numbers – questions 1-3 on pg 288, please show all your work