CHEM 103 Exam

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How do we access chemical energy?
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Terms in this set (85)
How do we access chemical energy?
Carry out chemical transformations which change the types (and strengths of) chemical bonds
Why do combustion reactions give off energy?
X-O bonds tend to be stronger than X-X and O-O bonds
Order wood, Coal, Natural Gas (methane), Gasoline (C8H18), & ethanol in terms of energy content (per gram) using table 4.3
CH4 > gasoline > coal > ethanol > wood
What are the major energy-related issues/challenges facing us today?
1.) Global Climate Change (CO2)
2.) Peak Oil
3.) Energy Security
4.) Growing Demand
5.) Impact on Economy
6.) Air & Water Pollution
What are the pluses of Coal?
- abundance
- spread out over the globe
What are the minuses of Coal?
- a solid
- lower energy content than petroleum, more CO2, emission per unit energy
-difficult & dangerous to obtain
-environmentally disruptive to obtain & utilize (remember So2 & NO2)
What are the pluses of natural gas?
- relatively abundance (we have a lot)
-'clean' due to high energy content & less CO2 emission per unit energy than oil
What are the minuses of natural gas?
- a gas (difficult to ship overseas)
-still does emit CO2
-combustion still can generate NO2
What are the pluses of oil/petroleum?
- high energy content
-a liquid (easy to pump, store, & transport)
- we know how to use it
What are the minuses of oil/petroleum?
- we're running out of it
- it tends to be in places that aren't friendly
- it does emit CO2
- combustion generates NO2
What's involved in refining crude oil to gasoline?-Distillation -Catalytic Cracking -Oligomerization -ReformingWhat's a Catalyst?By providing an alternative reaction pathway, reaction can proceed with less energy input -- catalyst is not transformed due to the reaction (catalyst is reused many times)What are the pluses of wind power?- wind is "free" - wind is abundant (but localized)What are the minuses of wind power?- have to build infrastructure (takes energy & $$$) -the wind doesn't blow all the time, have to have a load balance -wind isn't where people are have to transport the energy (with losses) - destroys views - covers landWhat goes into a lifecycle cost analysis?- energy for construction - transportation to site - operational phase energy use - decommissioning (transport, energy, recycling)What are the two major biofuelds?- ethanol (from sugars) - biodiesel (fatty acids)How do we/do we want to produce ethanol?Partial combustion/fisher-tropschWhat are the three major macronutrients?fats / carbohydrates (sugar) / proteinsOf the three major macronutrients, which has the higher energy content?FatsHow is biodiesel made?catalyst??When comparing a renewable energy source such as corn ethanol, what factors need to be considered on the biofuel side?- energy to grow the plants - energy to transport the raw material to the refinery - energy to refine the raw material - energy to transport the fuel (ethanol, biodiesel) - competition w/ food - animal feed as side product - energy to build to biorefinery - energy to build the farm machineryWhen comparing a renewable energy source such as corn ethanol, what factors need to be considered on the petroleum side?- the chemical content of the oil - energy to recover the petroleum - energy to transport the petroleum to the refinery - energy to refine the petroleum - energy to trasnport the fuel (gas, diesel) - energy to build new off-shore rigs - energy to build/maintain refineriesWhat is in wood?cellulose & ligninIs lignin a better energy source than cellulose?lignin has an energy content of 33kJ/g Sugars have an energy content of 17 kJ/gWhy can't "we" eat cellulose?Curved versus linear (rod-like) structureWhat are the pluses of Solar Thermal & PV?- Sunlight is "free" - sunlight is abundant (some places)What are the minuses of Solar Thermal & PV?- have to build infrastructure (takes energy & $$$) - the sun doesn't shine all the time, have to have a load balance - sunlight isn't where people are have to transport the energy (w/ losses) - destroys views - covers land - solar thermal uses water to drive turbinesFill in the blank in the following nuclear decay process:239 + 4 - 1 = 242How does radioactivity impact us and other living matter?high energy particles/ radiation destroys tissue and can cause molecular damageWhat types of cells are most impacted by radioactivity?rapidly dividing cells particularly susceptible (cancer treatment)What can we do to burn less gas?- slow down - use lighter cars (lighter materials, lighter batteries) - drive lessBased on the LLNL energy flow figure, reproduced below, the energy efficiency of electricity generation is ____%32.1One way to produce ethanol for use as a gasoline additive is the reaction of water vapor with ehtylene: is this reaction endothermic or exothermic?exothermicBased on the LLNL energy flow figure, reproduced below, [x1] quads of natural gas energy were used for residential applications in the US in 20114.83Based on the LLNL energy flow figure, reproduced below, [x1] quads of coal energy were used to produce electricity in the US in 201118Rank order CO2 emission from fossil fuels:coal >> gasoline > natural gasWhich of the following is the correct equation for the complete combustion of heptane?C7H16(I) + 11O2(g) -> 7CO2 (g) + 8H2O(l)"peak oil" is the concern that ___we are rapidly running out of petroleum worldwideWhich one of the following is not a "plus" of coalit has a lower energy content than petroleumWhich one of the following is not a " minus" of natural gasit is "clean" due to a high energy contentWhich one of the following is not a "plus" of oil?we're running out of itProved reservers are:- discovered - economically viable - still remaining in the groundA Quad is:one quadrillion BTU (British Thermal Units)Every year in the US, we get 20.8 EJ of energy from coal. How many kg of carbon dioxide is produced from the combustion of that coal?2.1 x 10 ^ 12 kgBased on the data in the EJ reserves table from the powerpoint slides, if the world burned 540 EJ/year from fossil fuels, it would take [x1] years to burn through the world's proved reserves?69 or 70C16H34 could be cracked into C7H14 andC9H20When C16H34 is cracked into C7H14 & a second product, the second product is an:alkaneA premium gasoline available at most stations has an octane rating of 92. What does this tell you about the knocking characteristics of this gasoline?this fuel has knocking characteristics similar to a mixture of 92% isooctane and 8% n-heptaneFor the following reaction: 3 CO + 7H2 -> C3H8 + 3H20. The reaction is called:fischer-tropsch processAccording to DOE's billion ton study, [x1] EJ of energy could be derived from biofuelds16From DOE's billion ton study, what fraction of the total resource potential would derive from agricultural resources72%Of the following, which one is not an energy input for corn ethanol productionanimal feedsAccording to the Argonne National Laboratory Study, in comparison to conventional gasoline production, corn ethanol production takes ___ times as much energy to generate 1 million BTU of energy at the pump0.60Which one of the following is not one of the ways that ethanol can be produced from biomass material?lye decomposition of fatsOf the four classes of molecules of life that we discussed at the beginning of the semester, which two are being used as biofuels- fats/fatty acids - carbohydrates/sugarsOf the three types of molecules of life listed below, which one has the highest energy content per gram?fatsExposure to ionizing radiation can cause cancer, yet a beam of ioninizing radiation can also be used to cure certain types of cancer. Why is this?if the energy of the ionizing radiation is high enough, it will kill cancer cellsWhy can't we "eat" cellulose?cellulose polymers are too stiff & rod likeIf lignin has an energy content of 33 kJ/g, where does it fit in terms of energy content?methane (natural gas) > gasoline > fats > lignin > coal > carbohydrates (sugar)The schematic below represents the reactor core of a nuclear power plant. Match each letter with the correct description:B: Cooling water out of core C: control rod D: cooling water into core E: fuel rodUsing table 7.4, if a person in the Ukraine at the Chernobyl plant received a dose of 1.5 x 10^5 millirem (mrem) of a radiation at the time of the accident what would be the likely short term effect?nausea, vomiting & loss of hair (1.00 - 2.00)Why types of changes are expected for the following types of radioactive decay? - Alpha Emission - Beta Emission - Gamma Emission- Alpha Emission: change in both atomic & mass # - Beta Emission: Change in atomic # - Gamma Emission: Change in NeitherWhich is a better source of energy? soybeans or wheatsoybeansSpent Nuclear Fuel (snf) is not radioactivefalseOf the following with is not a major constituent of wood?amyl pectinIn class it was estimated that ___ EJ of energy could be derived from Wind Power in the USA36How many moles of Neodymium (Nd) are needed to produce a 1 MW windmill?1040Which one of the following is not a "minus" of wind as an energy source?wind is abundantWhich one of the following is not one of the ways we can burn less gasoline?accelerate to the speed limit more quicklyIf the fleet average MPG were to increase from 18 MPG to 43 MPG and our annual usage of petroleum for transportation were 28 EJ then our annual usage of petroleum for transportation would drop to:(18/43) * 28 = 11.7 or ~ 12Which one of the following is not a "plus" of solar energy?it destroys viewsOf the following elements, which one could not be used as a dopant in a Si photovoltaic device?GeIf the grand solar plan discussed in class generated 35% of our current US energy demand, it would generate [x1] EJ of energy (assume current energy useage = 94.8 quad, 1 quad = 1.055 EJ)35Calculate the are necessary in square feet to produce 1MW of power from a solar photovoltaic array operating at 10% efficiency.100,000Of the following electricity generating processes, which one does not involved H2Ophotovoltaic power plantWhich one of the following is not a reason by air moves (wind)air moves from south to northWhich one of the following US wind farms has the largest capacityShepherds FlatOf the top 12 states for wind potential, which state is the only one with a top 10 capacity wind farmTexasOf the new generation electricity resources listed in Table 6.3 of G&R, which one is projected to provide the most expensive electricity?Solar thermalOf the new generation electricity resources listed in table 6.3 of G&R which one is projected to provide the least expensive electricity?natural gas - advanced CCOf the following, which one is the source of the most carbon emissions (energy useage) for the average american?transportationOf the following energy loss mechanisms in the average house, which one contributes the most to lost energyfloors, walls, & ceilingsOf the phantom loads of household devices, which one uses the most electricitylaser printers, onOf the following foods, which contributes the least to CO2 emissions: -red meat -milk -rice -fishmilkOf the following materials that we recycle, which one saves the most energy (reduced CO2 emissions) when we recycle italuminum