Unit 3 – Sections B, C & D Petroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum.

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 FuelsFossils 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.


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 !


CH4 + 2 O2 CO2 + 2 H2O + energy

The above reaction produces considerable thermal energy (heat).


CH4 + 2 O2 CO2 + 2 H2O + energy

Think of the above as a two step process.

Step 1 CH4 + 2 O2 C + 4H + 4O

All bond-breaking steps are energy requiring

processes called endothermic changes.


Step 1 CH4 + 2 O2 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.


Step 2 C + 4 H + 4 O CO2 + 2 H2O + ENERGY


Step 2 C + 4 H + 4 O CO2 + 2 H2O + ENERGY

Bottom line: MORE energy is given off in step 2 than is

taken in for step 1.

Step 1 CH4 + 2 O2 + energy C + 4 H + 4 O

The overall change is exothermic.


If MORE energy has to be added than is given off the reaction is endothermic.


In general, if a process converts potential energy into kinetic energy ... then the reverse

process

...converts kinetic energy back into potential energy.


Likewise, if a chemical reaction is exothermic (releases

heat)...then the reverse process

...is endothermic (converts thermal

energy into potential energy.)

B.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.

B.2 Energy Conversion(continued)

HW 2

Notes from B.4

B.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

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.5 1-4 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 28.45 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:

ANSWER:

B.5 Energy Conversion Efficiency1. 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 milesX =478 gallons

1 year

478 gallons

1 year

$3.00

1 gallonX =$1434

1 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.


b.If gasoline is $3.00 per gallon what would be spent in one year?

11,000 miles

1 year

1 gallon

50.0 milesX =220 gallons

1 year

220 gallons

1 year

$3.00

1 gallonX =$660

1 year

ANSWER: 220 gallons/yr

ANSWER: $660/yr


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 year0.75X =

359 gallons

1 year

359 gallons

1 year

$3.00

1 gallonX =$1077

1 year

ANSWER: 359 gallons/yr WASTED

ANSWER: $1077/yr WASTED


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 year0.60X =

94 gallons

1 year

11,000 miles

1 year

1 gallon

70 milesX =157 miles

1 year

ANSWER: 359 gallons/yr X $3.00 gallon = $283 WASTED

ANSWER: Car 1 478 gallon/yr – 157 gallon/yr = 321 g/yrCar 2 220 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.


b.If gasoline is $3.96 per gallon what will I spent in one year?

X =

X =

ANSWER:

ANSWER:

B.6 Combustion

Pre-read B.6 – pg 248-251

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 CombustionWith enough O2 and complete combustion the burning of a hydrocarbon is expressed as follows:

Ethane C2H6

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 C2H6 + 7 O2 4 CO2 + 6 H20 + ? thermal energy

Per the table 3.6 on page 250 ethane releases 1560 kj/Mol

2 C2H6 + 7 O2 4 CO2 + 6 H20 + 3120 kj

B.7 Using Heats of Combustion(continued)

Sample: How much thermal energy would be produced by burning 12.0 g octane, C8H18?

12.0 g octane

47.8 kj

1 g octaneX = 574 kj

ClassworkClass 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 Combustion1. Write chemical equations including thermal

energy for :a.propane

b.Butane

c.octane

C3H8 + 5 O2 3 CO2 + 4 H20 + 2200 kj

2 C4H10 + 13 O2 8 CO2 + 10 H20 + 5718 kj

2 C8H18 + 25 O2 16 CO2 + 18 H20 + 10900 kj

B.8 Heats of Combustion(continued)

1. Write chemical equations including thermal energy for : (continued)

d.decane

2 C10H22 + 31 O2 20 CO2 + 22 H20 + 13540 kj


2. a. How much thermal energy is produced burning 2 Mol of octane?

2 Mol octane5450 kj

1 Mol octaneX = 10,900 kj

ANSWER: 10,900 kj produced


3. a.Write a chemical equation for burning coal including the thermal energy.

C (s) + O2 CO2 + 394 kj


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

1 Mol C

12.01 g C X = 32.8 kj/Mol

Burning coal releases

Octane is better on a mass basis.


2. b. How much thermal energy is produced burning 1 gallon of octane?

2 Mol octane5450 kj

1 Mol octaneX = 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.


At that time celluloid (wood) and shellac (animal material) were the only source for commercially produced polymers.


Polymers are typically large molecules, 500 to 20,000 repeating units. The single unit is known as a monomer.


Many of today’s polymers are created using compounds produced using oil or natural gas and they are called petrochemicals.


Most petrochemicals serve as raw materials producing a wide range of polymers.


Synthetic polymers include:• Paint components• Fabrics• Rubber• Insulating materials• Foams• Adhesives• Molding• Structural materials


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.


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.

Ethene water Ethenol

Acid

catalyst


Polymers formed by reactions such as this are called addition polymers

Polyethene is an example which is commonly used in grocery store bags.

Ethene water Ethenol

Acid

catalyst

HW

Notes on section C.2 Polymer Structure & Properties & C.3 Beyond Alkanes on pgs 265-267

C.2 Polymer Structure & PropertiesWhile 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.


Polymers can be enhanced by adding molecules that act as internal lubricants.

Add lubricant and the material becomes flexible.


Added molecules acting as lubricants may form side chains off the main polymer chain.

They are called branched polymers.


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.


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.


Unsaturated hydrocarbons are better builder molecules than alkanes.


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 267-269)

On a lined piece of paper answer questions:• 2• 3 (all)• 4 a• 5• 6• 7• 8• 9

•10 (nothing to write)• 11•12•13 (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.


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 283-284, remember complete sentences for complete credit.

D.2 Fuel Sources over the Years

HW

Notes on D.3 on pgs 284-285.

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

Pro ConMajor 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


Coal liquefaction is the technology of turning coal to a liquid fuel.

Pro ConU.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)


Biodiesel is using technology to convert plant or animal fat into diesel liquid fuel.

Pro ConAny 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


hydropower is power that is derived from the force or energy of moving water.

Pro ConEnvironmentally clean potential is limited globally to about

5 to 10% of energy needs

Inexpensive dependability is an issue; think prolonged droughts


(continued)

Wind power is power that is derived from the force or energy of moving air.

Pro ConEnvironmentally clean Technology susceptible to damage

from weather events

Inexpensive!!! wind resource needs to be at over ten mph for long periods of time


Burning Biomass is electricity derived from burning organic matter, particularly wood.

Pro Cona 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


Geothermal energy taps into the vast stores of natural heat within the Earth.

Pro Connearly 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?


Compressed Natural gas vehicles run on methane (CH4) rather than gasoline or diesel.

Pro ConFuel widely available increased vehicle cost (refueling

system)

Less pollution than gasoline engines

Higher fire risk danger resulting from collisions


Fuel cell vehicles run on electricity generated to power the vehicle.

Pro ConMore efficient than internal-combustion engines

fuel handling

Environmentally clean Fuel-cell manufacturing costs

Based on the following reaction:

2 H2 + O2 2 H2O + electrical energy (and some thermal)


Hybrid vehicles run on gasoline-burning engine as well as a battery-powered electric motor.

Pro ConGreater 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

DONE – next stop test on sections B,C & D

Unit 3 – Sections B, C & D Petroleum: An Energy Source, A Building Material Source & Energy Alternative to Petroleum.

Documents

energy slide

energy conversion energy

units of energy

energy efficiency

kinetic energy

energy source

energy states

energy of position