energy: hard work & hot stuff energy is the ability to do work. work is done when movement...

Energy: Hard Work & Hot Energy: Hard Work & Hot StuffStuff

• Energy is the ability to do work.• Work is done when movement occurs

against a restraining force, and it is equal to the force multiplied by the distance over which the motion occurs.

• Heat is that which flows from a warmer to a cooler substance

• Temperature is a property that determines the direction of heat flow. When two bodies are in contact, heat always flows from the object with a higher temperature to the one with lower temperature.


• Heat is a consequence of motion at the molecular level. When matter, for example liquid water in a pan, absorbs heat, its molecules move more rapidly.

• Temperature is a statistical measure of the average speed of that motion. Hence, temperature rises as the amount of heat energy is a body increases.


• Units of energy are termed the Joule (J).

• Calories are also used as a measure of energy.

• 1cal = 4.184J• 1Cal = 1kcal = 1000 cal• 1Cal = 4184J

Your TurnYour Turn

• Convert the 425 kcal released when a donut is metabolized to joules. Then calculate the number of books you could lift to a shelf 6 feet off the floor with that amount of energy. (It takes 1J of energy to lift a book 4 inches.)

Your TurnYour Turn

• A 12 oz can of a soft drink has an energy equivalent of 92kcal. Assume that you use this energy to lift concrete blocks that weigh 22lb (10kg) each. How many of these blocks could you lift to a height of 4 feet with this quantity of energy? (It takes 10J of energy to lift a book 4 inches.)

Energy Conservation and Energy Conservation and ConsumptionConsumption

• Strictly speaking, energy is not consumed.

• Law of Conservation of Energy or the First Law of Thermodynamics assures us of this.

• The energy in the universe is constant.• However, energy sources like coal,

oil, natural gas are consumed.• The U.S. and Canada use more fossil

fuel than any nation at 95 million kcal.

Energy Conservation and Energy Conservation and ConsumptionConsumption

• Graphs like on ICT show that the world’s reliance and usage of fossil fuel is growing exponentially.

• We are using 5 times as much fossil fuels in 2000 than we did in the 1950’s.

• Our main sources of energy are oil, natural gas, coal, nuclear power and hydropower, geothermal, wind and solar power in that order.

Consider This…

• Imagine that you are put in a time machine and transported 200 years into the future. You become an instant celebrity. The talk show host of the day invites you in to be interviewed. The first question is “How could the people of your century feel justified in using up so much of the world’s store of non-renewable resources such as oil and coal? What is your answer?

Zero Talking on this ActivityZero Talking on this Activity• Get in groups of 3—2 min• Give your essay to the person to the right for

them to read—10 sec• Read the article that you now have and respond

to them in another short paragraph—2 min• Pass your paper to the right again—10 sec• Read the article and the response and write a

response of your own commenting on the original and the response—2 min

• Give the paper back to the original author—2 min

• Read the responses to your essay—2 min• Discuss your papers and responses with each

other—2 min

Energy: Where from and Energy: Where from and How Much?How Much?

• At a time when the nation is seeking new sources of energy, it is reasonable to ask what is it that makes some substances such as coal, oil or wood usable as fuels, while many others are not.

• To find the answer, we must consider the properties of fuels and the means by which energy is released from them.


• The most common energy-generating chemical reaction is burning or combustion.

• Combustion is the combination of the fuel with oxygen to form CO2, H2O and energy.

• The stored energy (potential energy) of the reactants is more than the stored energy of the products, so the 1st Law of Thermodynamics tells us that energy must be given off (usually as heat).


• The above reaction is exothermic.• This means that energy was given

off as the reactants broke bonds and reformed bonds to make products.

• Endothermic reactions are those that need energy to be added to the reactants in order to turn into products.

CH4 + O2 CO2 + H2O + Energy


• The amount of heat energy produced by a reaction such as the previous can be calculated using a calorimeter.

• The amount of heat generated depends on the amount of fuel burned.

• Heat of combustion is the quantity of heat energy evolved when a specified amount of a substance burns in oxygen. (kJ/mole or equivalents)


• If the heat of combustion of methane is determined by calorimetry to be 802 kJ/mole, it means that every mole of methane emits 802kJ of energy.

• We can use factor label to determine that the amount of energy given off per gram is 52kJ/g.

• The fact that heat is evolved signals that there is a decrease in the energy of the chemical system during the reaction.


• The fact that heat is evolved signals that there is a decrease in the energy of the chemical system during the reaction.

• So, the energy change is reported as -802kJ/mole.


• But where does the energy come from? We have discussed that energy is released during a reaction such as this, and that the reactants have more energy than the products, but where does the energy come form?

• The answer is found in the molecular structures of the compounds…

Today

• Pick up more notes at desk nearest door. • WHAT!? MORE NOTES?!

• Yes, more notes…• Get out a sheet of paper, periodic table, pen/pencil, and a calculator for the graded

quiz. • QUIZ?!

• Yes, a graded quiz.• GRADED QUIZ?! THIS STINKS!

Yes, I know.

Today’s Graded Quiz CheckAbsolutely no talking or asking questions—if you are talking you will get no credit for this graded

quiz.1. Define electronegativity (χ).2. Which has a higher χ,

Ba or OCl or FN or C

3. Draw NF3 and check the formal charges.

4. List two units to measure heat.5. What does it mean to say the heat of

combustion of methane is -802kJ/mol?

Final Quiz Question

6. According to the information given to you, the heat of combustion of methane is 802kJ/mole. Methane is usually sold by the standard cubic foot (SCF). One SCF contains 1.25moles of CH4. Calculate the energy (in kJ) that would be released by burning 15 SCF of methane. (Hint: this is a factor label problem)

Energy: Where from and How Much?Energy: Where from and How Much?

• Bond breaking is endothermic—need energy to tear away atoms.

• Bond forming is exothermic.

C

H

H

H O

H

O

O=O

O=O

O=C=O

+ HH

+

H H

Write the balanced equation for the combustion of methane (CH4).

Draw all the molecules from this equation.


• For this reaction to take place, 4 C-H bonds and 2 O=O bonds are broken and 2 C=O and 4 O-H bonds are formed.

C

H

H

H O

H

O

O=O

O=O

O=C=O

+ HH

+

H H

Calculating Energy Changes Calculating Energy Changes in Chemical Reactionsin Chemical Reactions

• Bond energy is the amount of energy that must be absorbed to break a specific chemical bond.

• The more bonds broken, the more energy it takes.

• All values in the table are given in kJ/mole and are given a positive sign.

• Energy used to break bonds is given (+) and energy given off is given (-).

Calculating Energy Changes Calculating Energy Changes in Chemical Reactionsin Chemical Reactions

• Breaking Bonds (endo)• 4 C-H bonds 411kJ = 1644kJ• 2 O=O bonds 494kJ = 988kJ• Total energy absorbed 2632kJ

• Making Bonds (exo)• 2 C=O bonds -799kJ = -1598kJ• 4 H-O bonds -459kJ = -1836kJ• Total energy released -3434kJ• Net energy -802kJ (released)

More Funner Way

ΔHºrxn = (Σ bonds broken) – (Σ bonds formed)

Heat of the reaction at standard

conditions

Sum of

You Try• Determine the heat of combustion of one

mole of propane (C3H8).• Acetone (H3CCOCH3) can be converted to

isopropyl alcohol (H3CHCOHCH3) by reacting it with H2 gas. Calculate the heat change of this reaction.

• Oxygen difluoride reacts with water to form oxygen and hydrofluoric acid. If the ΔHºrxn is -318kJ/mole, what is the bond dissociation energy associated with an O—F bond?

• How much energy is given off when 150mL of ethanol (C2H5OH) is burned on a desk? (Density = 0.85g/mL)

You Try

• How much energy is given off when 100g of methane reacts with oxygen?

Hess’s Law• Hess noticed that heat change was a state

function—which means…• That it doesn’t matter the path you take to

get to the end as long as you get to the end.

• A state function is like going to the baseball field.

• There are many paths that you can take to get to the field—but the displacement of your body from this spot to the field is the same.

Hess’s Law

UU

BB BB FielFieldd

Hess’s Law• In all cases, you ended up about 500 feet

from where you started.• Hess didn’t care about the path you took

as long as you ended up in the same place.

• He took this idea into the chemistry world.• He stated: in going from a particular set of

reactants to a particular set of products, the change in enthalpy (H) is the same whether the reaction took place in one step or a series of steps.

Hess’s Law

• N2(g) + 2O2(g) 2NO2(g) ΔH1 = 68kJ

• This shows the reaction in one step.• But the reaction can be thought of as

occurring in 2 distinct steps…

• N2(g) + O2(g) 2NO(g) ΔH2 = 180kJ

• 2NO(g) + O2(g) 2NO2(g) ΔH3 = -112kJ

• N2(g) + 2O2(g) 2NO2(g) ΔH1 = 68kJ

Hess’s Law

• Often we will know the ΔH of a reaction or we can use calorimetry to get it.

• But sometimes we are unable to use any means to calculate it—other than Hess’s Law.

Hess’s Law• For example it is too difficult to use calorimetry

to calculate ΔH of diborane (B2H6). So we use Hess’s Law and some reactions that we can determine ΔH for.

• 2B (s) + 3H2 (g) B2H6 (g)

• We then use the following data…• 2B (s) + 3/2O2 (g) B2O3 (s) ΔH = -1273kJ

• B2H6 (g) + 3O2 (g) B2O3 (s) + 3H2O (g) ΔH = -2035kJ

• H2 (g) + ½ O2 (g) H2O (l) ΔH = -286kJ

• H2O (l) H2O (g) ΔH = 44kJ

All you!• Given the following data…

• 2O3 (g) 3O2 (g) ΔH = -427kJ

• O2 (g) 2O(g) ΔH = +495kJ

• NO(g) + O3(g) NO2(g) + O2 (g) ΔH = -199kJ

• Calculate H for this reaction…

• NO(g) + O(g) NO2(g)

Getting a Reaction Started: Getting a Reaction Started: Activation EnergyActivation Energy

• CH4 + O2 CO2 + H2O + energy• What happens when gas like methane is

pumped into a room with oxygen?• Nothing.• Just because 2 chemicals are in contact

with each other does not mean that a reaction will occur even if it is exothermic.

• A spark or a flame is needed to start the reaction and get the methane to burn in oxygen.


• The spark or flame supplies the energy needed to jumpstart the reaction—called activation energy.

Energy of Reactants

Energy of Products

Activation Energy

Energy

-ΔH


• The bigger the hill, the slower or less likely the reaction will take place.

• The lower the hill, the faster the reaction will take place.

• Some possible fuels have too high of Ea and are not useful and some have to low of a Ea and are dangerous.

Other Ways to get a Reaction to Other Ways to get a Reaction to Go!Go!

• Grinding up the fuel (coal) which increases the surface area will speed up the reaction.

• Increasing the temperature of the fuel mixture will increase the rate of the reaction as well.

Changing Gears from Changing Gears from ReactionsReactions

• We have been talking about the heat gained or lost during a chemical reaction and it has

been a load of funload of fun.• Now we are going to look at how

heat is gained or lost when we look at the physical changes of

melting, boiling and temperature change.

Today…

• If you missed yesterday copy this website.

• The answers are due on Monday.•http://www.mrfischer.com/wp-content/uploads/23-thermwebquestques.pdf

• By Monday BONUS points on Quest possible.

• Bring empty and clean 2L bottles get 1% added to quest grade (Max 5%)

• Bring 1L bottle of vegetable oil (5%)

http://www.mrfischer.com/wp-content/uploads/23-thermwebquestques.pdf

http://www.mrfischer.com/wp-content/uploads/23-thermwebquestques.pdf

Heat to Change Temperature and Heat to Change Temperature and to Change Phaseto Change Phase

• If ice turns into water, what is needed?• If water turns into vapor, what is needed?• If the temperature of water increases, what is

needed?• HEAT!!!!

q = mCpΔT

heat

mass

Amount of heat needed to increase the temp of 1g of a substance by 1ºC

Change in temperature

Specific heat

ΔT = Tf - Ti


• Specific heat (Cp) is different for every substance and it is different for each phase of a given substance.

• Cp ice = 2.02 J/gºC• Cp water = 4.2 J/gºC• Cp vapor = 2.06 J/gºC

• Ex—How much heat is needed to raise the temperature of 150g of water from 2.0ºC to 93ºC?


• If ice is melted, heat is needed, but we don’t look at the temperature.

• Energy added is used to stretch bonds not make the particles move faster (T).

• Types of bonds…• Intra-molecular—atoms are held

together inside a molecule.• Inter-molecular—molecules are held

together in a substance.


• The equation we need to determine the heat necessary to melt a given amount of solid is…

q = mΔHfus

heat

mass

Amount of heat needed to melt 1g of a solid

Heat of Fusion


• Heat of fusion (ΔHfus) is different for every substance.

• ΔHfus ice = 330 J/g

• Ex—How much heat is needed to melt 150g of ice?


• If water is boiled, heat is needed, but we don’t look at the temperature.

• Energy added is used to break bonds not make the particles move faster (T).


• The equation we need to determine the heat necessary to boil a given amount of liquid is…

q = mΔHvap

heat

mass

Amount of heat needed to boil 1g of a liquid

Heat of Vaporization


• Heat of vaporization (ΔHvap) is different for every substance.

• ΔHvap water = 2260 J/g

• Ex—How much heat is needed to boil 150g of water?


• Putting it all together…

Heat (q in Joules)

T (ºC)

Add heat and T inc…q = mCpΔT



Add heat & melt… q = mΔHfus

Add heat & boil… q = mΔHvap

S

G

L

0ºC

100ºC

Try em!1. How much heat is absorbed by a 6.00g piece of -

13.0ºC ice cube when it is heated to 0.0ºC?• 160J2. How much energy does it take to melt the 6.00g ice

cube if it is at its melting point?• 1980J3. How much energy is absorbed by 6.00g of liquid

water at 0.0ºC to bring it to water’s boiling point?• 2500J4. How much energy does it take to turn 6.00g of liquid

water at 100.0ºC to steam?• 13600J5. How much energy is needed to take 6.00g of steam at

100.0ºC to steam at 120ºC?• 250J

Ask this question: is the substance

changing temperature or

changing phase?

If it is changing temperature, which eq’n works? If it is changing

phase, which eq’n works?

OK...try this

• How much heat is needed to turn ice at -11ºC into water at 55ºC?


• If a piece of hot metal is dropped in a beaker of cool water, what happens to the temperature of the metal? The water?

• So, if the water absorbs 100kJ of energy the metal loses…

• 100kJ of energy.• The metal’s temperature drops.


• So, the heat lost by an object is gained by another object.

• Heat lost = -q• Heat gained = +q• So, for the hot metal/cool water example,

the heat gained by the water (+qwater) equals the heat lost by the metal (qm).

• +qwater = -qm

• qwater + qm = 0


• If a piece of ice melts, where does the heat come from?

• Something outside of the ice cube.• If we place and ice cube in a glass of Kool-

Aid what supplies the heat to melt the ice?• Mostly the Kool-Aid.• So, if the ice absorbs 100kJ of energy the

Kool-Aid loses…• 100kJ of energy.• The Kool-Aid’s temperature drops.


• What if we have a 55.0g of a piece of metal, say iron, at 99.8ºC and we place it in a 225g of water at 21.0ºC.What is the specific heat of the metal if the final temperature of the water and Fe is 23ºC?


• Heat lost by iron is –qFe

• Heat gained by water is +qH2O

• -qFe = +qH2O

• qFe + qH2O = 0• What happens to the iron as heat is lost?• Temperature drops.• What equation do we use for

temperature change?• q = mCpΔT


• What happens to the water as heat is gained?

• Temperature rises.• What equation do we use for

temperature change?

• q = mCpΔT

• So we can rewrite the previous eq’n as…

• (mCp ΔT)Fe + (mCp ΔT)H2O = 0


• (mCpΔT)Fe + (mCp ΔT)H2O = 0

• (55.0g)(X)(–76.8ºC) + (225g)(4.2J/gºC)(2.0ºC) = 0

• -4224g ºC X + 1890J = 0• -4224g ºC X = -1890J • X = -1890J / -4224g ºC• 0.448 J/gºC


• Another example…• What is the minimum amount of ice

at 0ºC that must be added to the contents of a 340. mL glass of Kool-Aid to cool it from 20.5ºC to 0.0ºC. Assume Cp of Kool-Aid is the same as liquid water and that no heat is gained or lost to the surroundings.


• qice + qKoolAid = 0

• What happens to the ice when heat is added to it?

• What happens to the Kool-Aid as heat is lost?

• The q’s then are…

• (mΔHfus)ice + (mCp Δ T)KA = 0

• (m)(330J/g)+(340g)(4.2J/gºC)(-20.5ºC)=0

• m = 88.7g ice needed

Old FuelOld Fuel• Coal, oil and natural gas possess many of

the properties needed in a fuel.

• So, most of the energy we use comes from these sources.

• These fossil fuels can be thought of as sunshine in the solid, liquid and gas state.

• Sunlight was captured millions of years ago in green plants that over the years has decomposed and highly compressed into the fossil fuels we use today.

Old FuelOld Fuel

• 2800kJ + CO2 + H2O C6H12O6 + O2

• Plants require about 2800kJ of energy from the sun for each mole of glucose they produce.

• On the other hand we use the 2800kJ of energy per mole of glucose we eat.

• This energy is converted into the energy that our muscles and nerves use throughout the day.

CoalCoal• When the Industrial Revolution began,

wood was the major source of fuel in England.

• Over a short time all the forests were cut down and wood was scarce…so coal took over.

• Burning 1g of coal produces 30kJ of heat while burning 1g of wood produces only 10-14kJ of heat.

• Coal was definitely the choice.

CoalCoal• Coal has a chemical formula of

C135H96O9NS.

• In addition samples of coal also contain small amounts of Si, Na, Ca, Al, Ni, Cu, Zn, As, Pb and Hg.

• The more impurities the lower the grade and the lower the amount of heat released during the burning of coal.

Try This OneTry This One• Assuming the composition of coal can be

approximated by the previous given chemical formula, calculate the mass of carbon (in tons) contained in 1.5 million tons of coal, which is the amount of coal that a typical power plant would burn. (Hint: Mass %)

PetroleumPetroleum• Around 1950, petroleum surpassed coal

as the major energy source in the US.

• It is liquid so it is easier to pump from the ground reserves, transported via pipelines and fed automatically to its point of use.

• Also petroleum yields about 48kJ per gram burned—much more than coal.

PetroleumPetroleum• However, crude oil must be processed

before it can be used.

• The crude oil is refined by a process called distillation into many different usable forms of fuels.

• It can be separated into gasoline, kerosene, gas oil, lubricating oil and petroleum gas.

Manipulating MoleculesManipulating Molecules• Research has found that not all compounds

distilled from crude oil are useful for desired applications.

• Chemists have devised ways to take these high molecular weight compounds and create smaller more usable compounds through a process called cracking.

• C16H34 is a byproduct of distillation but is not very useful.

• C16H34 C8H18 + C8H16 or

• C16H34 C5H12 + C11H22

Seeking SubstitutesSeeking Substitutes• Because the world’s coal supply is much

greater than our available oil reserves, there is interest in converting coal into gaseous and liquid fuels that are identical with or similar to petroleum products.

• An old technology that does this is blowing steam over hot carbon called coke.

• Coke is the impure carbon that remains after volatile components have been distilled from coal.

• C(s) + H2O(g) CO(g) + H2(g)

Seeking SubstitutesSeeking Substitutes• The CO and H2 are called water gas and

were used as energy to light cities.

• Fischer-Tropsch process for producing synthetic gasoline uses this reaction.

• The CO and H2 are passed over an iron or cobalt catalyst which promotes the formation of hydrocarbons.

• The hydrocarbons range in size from methane to 5-8 carbon atoms (that are typically used in gasoline).

Seeking SubstitutesSeeking Substitutes• This process is economically feasible in

locations where coal is cheap and plentiful and oil is scarce and expensive.

• This is the case in South Africa, where 40% of the gasoline is obtained from coal.

• In the future, such technology might become competitive in other parts of the world.

Seeking SubstitutesSeeking Substitutes• The concerns about dwindling supplies of

petroleum have also led to the use of renewable energy sources.

• This generally refers to biomass which are materials produced by biological processes.

• Wood is one such source, but there is far too little wood to meet our energy demands.

• Plus we would be destroying good CO2 absorbers.

Seeking SubstitutesSeeking Substitutes• Our favorite, ethanol (C2H5OH) is another

alternative biomass fuel getting a lot of press of late.

• Ethanol is formed by the fermentation of carbohydrates such as starches and sugars.

• Enzymes released by yeast cells catalyze the reaction that is typified by…

• C6H12O6 2 C2H5OH + 2 CO2

• The burning of ethanol releases 1367kJ per mole burned. (~30kJ/g—lower than 48kJ/g produced by gasoline)

Seeking SubstitutesSeeking Substitutes• The burning of ethanol releases 1367kJ per

mole burned.

• Corn is being used to create ethanol and added to unleaded gas at 85:15 to create E85 gas.

• In general, E85 gas is cheaper than unleaded gas, but you can only use E85 gas in certain vehicles.

• Should Oil Companies be banned from Owning Ethanol Plants ?

Seeking SubstitutesSeeking Substitutes• Ethanol or flex-fuel cars are common in

countries such as Brazil.

• They farm sugar cane and convert it to ethanol and run any mixture of ethanol-gas they choose.

• But by using computer sensors that adjust to whatever mix is in the tank, flex car engines run on either ethanol, gasoline, or any combination of the two.

• Gas-electric hybrids are another option.

Seeking SubstitutesSeeking Substitutes• Unlike hybrids sold in the US, for example,

flex cars sold in Brazil don't cost any more than traditional models.

• In fact, some models are only available with flex engines now.

• Ethanol engines use 25 percent more ethanol per mile than gasoline. But ethanol usually sells at somewhere between a third to half of the price of gas.

Seeking SubstitutesSeeking Substitutes• Another potential energy source is a

commodity that is cheap, always present in abundant supply and is always being renewed.

• It is garbage.

Seeking SubstitutesSeeking Substitutes• Elk River Resource Recovery Facility (ERRRF) in

Hennepin, MN processes garbage into refuse derived fuel (RDF).

• ERRRF serves five area counties. Hennepin County contracts to deliver up to 235,000 tons of garbage to ERRRF each year.

• The RDF is transported to a nearby power plant, where it is combusted to generate electricity.

• The RDF from Hennepin County garbage produces enough electricity to provide power to the equivalent of 12,700 homes each year.

Seeking SubstitutesSeeking Substitutes• This resource recovery approach

simultaneously addresses two major problems…

• The growing need for energy

• The growing mountain of waste

WriteWrite• The Elk River Resource Recovery Facility has been

the subject of a great deal of controversy for the county residents. The idea of generating usable energy from trash sounds great, until the facility is built in your neighborhood. This is a problem faced by the homeowners and residents in the area surrounding the plant. To address residents’ concerns, an open meeting between the residents and representatives of the plant is scheduled. Managers from the plant, engineers, and representatives of the state pollution control agency will be present. Prepare a list of questions that you, as a resident in this area, would like to see addressed at this meeting.

The Case for ConservationThe Case for Conservation• The fundamental feature of the universe is that

energy and matter are conserved.

• However the process of combustion degrades both energy and matter, converting them to less useful forms.

• As residents of the universe, we have no choice but to obey its unavoidable laws.

• The planet’s fossil fuel stores are limited and although we could go many years without running out, there will come an end.

The Case for ConservationThe Case for Conservation• The demands of the power plants in the world

for coal, oil and gas are huge.

• Fibers, plastics, rubber, dyes, medicines, and pharmaceuticals are currently produced from petroleum.

• Once the petroleum is gone, we will need to find a different way to make these as well.

• On a positive note, the world is aware of this situation and many have been working to find better alternatives all the time.

The Case for ConservationThe Case for Conservation• To a considerable extent, taste ultimately

influences what technology can do to conserve energy.

• As individuals and as a society, we must decide what sacrifices we are willing to make in speed, comfort and convenience for the sake of our dwindling fuel supplies and the good of the planet.

The Case for ConservationThe Case for Conservation• The costs might include higher taxes, more

expensive gasoline, and electricity, fewer and slower cars, warmer buildings in the summer and cooler ones in the winter.

• One thing seems clear: the best time to examine our options, our priorities, and our will is before we face another full blown energy crisis.

ReviewReview

• What does the 1st Law of Thermodynamics state? (a.k.a. Law of Conservation of Energy)

• Define energy.• Define work.• Define heat.• What is the unit for energy?• What is the difference between and exo

and endothermic reaction?

ReviewReview

• Define activation energy and draw an energy graph showing an exothermic reaction.

• What is combustion?• Draw these molecules…O2, CO2, H2O,

CH4, C3H8)• What is bond energy?• Is bond breaking an endo or exothermic

process?

ReviewReview

• Is bond forming an endo or exothermic process?

• What is the energy given off or absorbed for the reaction of octane (C8H18) with O2 to form CO2 and H2O?

• What are three main fossil fuels used today?

• How are fossil fuels like sunshine in the solid, liquid or gas form.

ReviewReview

• How does the 1st Law of Thermodynamics illustrated through fossil fuels?

• How does the 1st Law of Thermodynamics illustrated through photosynthesis?

• What is “cracking” and when is it used during fossil fuel refinement?

• Rank the following in order from lowest to highest energy output per gram used: petroleum, coal, ethanol, wood.

ReviewReview

• Give a reason why it is good to use wood as fuel and one that is not good.

• Give a reason why it is good to use coal as fuel and one that is not good.

• Give a reason why it is good to use petroleum as fuel and one that is not good.

• Give a reason why it is good to use ethanol as fuel and one that is not good.

ReviewReview

• How is coal converted to synthetic gasoline?

• What is E85?

• How is ethanol made?

• What are flex-fuel cars?

• Who is ahead of the US in the usage of ethanol fueled cars?

• What is being done in Hennepin MN?

The Other Side of the The Other Side of the Inconvenient TruthInconvenient Truth

• Get ready to take Notes on some videos.

Message to Seniors…Message to Seniors…

• "Senior skip day may result in the loss of special privileges planned for your class, including your senior day breakfast, the senior cookout on your last day, and of

course Baccalaureate and Graduation. This class at our school gets out waaaaay earlier than most schools with the Senior Seminar, so there should be no need for a skip day.

Please know that the administration will find out and will follow up with the appropriate

consequences." • So sayeth el Bridges

energy: hard work & hot stuff energy is the ability to do work. work is done when movement...

Documents

heat energy

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energy conservation

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measure of energy

energy equivalent

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