Section 3 Study Set #1
What is potential energy?
Stored energy. Energy due to the position of an object. Textbook on table. The heavier the book, and the higher it is lifted, the more potential energy it will have. The potential energy of a reactant or product is product is often referred to as it's "chemical energy."
What is energy?
The capacity to do work. Like the energy of a crowd, you can't see it, can't measure it, but you know it is there.
What is combustion?
The chemical process of burning, that is, the reaction of fuel with oxygen to release energy in the form of heat and light
What is the predominant cause of the rise in atmospheric CO2 concentrations over the past 50 years?
The combustion of fossil fuels
What is the first law of thermodynamics? What is an example?
The energy of the universe is constant, or, energy can neither be created nor destroyed; but it can be converted from one form to another. Energy is cyclical EX. Photosynthesis > plant material + 02 > combustion > heat + light + co2> h20
What is the 2nd Law of Thermodynamics?
The entropy of the universe is always increasing
Bigger compounds have higher boiling points because ...
The larger they are the heavier there molar mass is the harder it will be to boil them
What is an atomic mass?
The mass (in grams) of the same number of atoms that are found in exactly 12 g of carbon 12 - no more than a tablespoon of soot.
Which parts of the carbon cycle are most influenced by human activities?
The parts of the carbon cycle most influenced by human activities are burning fossil fuels and deforestation. The extra anthropogenic atmosphere CO2 also increases the rate of CO2 absorption in the oceans
What is photosynthesis?
The process by which green plants (including algae) and some bacteria capture the energy of sunlight to produce glucose and oxygen from carbon dioxide and water.
Define EXOTHERMIC
The process of when energy is released during the course of a chemical reaction
Which processes add carbon (in the form of CO2) to the atmosphere?
The processes that add carbon to the atmosphere include emissions from oceans, respiration, burning fossil fuels, and deforestation.
What is the Law of Conservation of Energy?
We cannot create or destroy energy. We can change what it is being used for and convert it from one form to the other. The total energy of the universe is constant. Just like the total mass is constant - mass cannot be created or destroyed. EX. Energy from sun is transferred into plan material into chemicals. !Although energy is still there, not all of it is efficient/ useful!
What are some of the benefits of coal?
We get a lot more energy out of it. It is also relatively easy to find. There are a lot of reservoirs and deposits of coal that are fairly easy to get to. However, mining produces dangers of its own.
What is a reservoir?
a place where fluid collects, especially in rock strata or in the body.
State whether these processes are endothermic or exothermic. a. Charcoal burns in an outdoor grill. b. Water evaporates from your skin. c. Glucose is synthesized in the leaves of a plant by photosynthesis.
a. exothermic b. endothermic c. endothermic
Example of three important endothermic reactions
---The decomposition of O3 to yield O2 and O ---The combination of N2 and O2 to yield two molecules of NO ---Photosynthesis
Molecules with high potential energy...
...make good fuel
Many atomic nuclei are unstable and will exhibit...
...radioactivity, emitting energy as they decay
The higher the temperature of the steam...
...the more efficient the power plant
The overall energy change associated with a chemical reaction depends on...
...the net effect of the bond breaking and bond forming.
About who much CO2 is released per year by deforestation? Why does deforestation cause this increase of carbon?
1.5 Gt of carbon to the atmosphere. Trees are efficient absorbers of carbon dioxide. When removed, and through the burning of wood, vast quantities of CO2 are generated. If the trees are left to decay that process also releases carbon dioxide, although more slowly. It is estimated that the loss in CO2 absorbing capacity may reach 80%.
Calculate the mass in grams of 6*10^15 nitrogen atoms
6*10^15 ( 2.34*10^-23) = 1.40 * 10^-7
What is Avogadro's number?
6.02 * 10^23 - the number of atoms in exactly 12 grams of carbon 12
Calculate the mass % of carbon in coal C135 H96 O9 NS 12% 50% 85% 135%
85% 135(12.5) +96(1) +9(16)+ 14+ 32 135*(12)/1906 =85%
Which of these statements about biodiesel is NOT true? A. Biodiesel has been withdrawn from several states due to health concerns B Biodiesel can be used in diesel engines without major modifications Biodiesel is non-toxic and biodegradable Biodiesel is made from renewable sources such as vegetable oils and animal fats
A
What is the equation for burning fossil fuels/combustion reaction?
A combustion reaction always includes a hydrocarbon and oxygen as the reactants and always produces carbon dioxide and water as products. ... First, balance the carbon and hydrogen atoms on both sides of the equation. Next, balance the oxygen atoms, and finally, double-check to make sure everything is still balanced.
What is a mole?
A measure of the amount of something 6.02 x 1023 "things"
Which of the following would you expect to have the MOST entropy? An ice cube Water as a liquid Steam A mixture of gases
A mixture of different gases has the most disorder
What is the Global Warming Potential (GWP)?
A number that represents the relative contribution of a molecule of the atmospheric gas to global warming
Which of the following are criteria air pollutants? SO2 NO2 PM All of the above A and B only
All three of these are criteria air pollutants - and we see all three of them with the burning of coal. We get a lot of carbon dioxide, and also sulfur dioxide, and nitrogen oxide, as well as soot, ash (particulate matter) from the burning of coal. This is what happened with the London Fog.
What is heat?
Always flowing from hot to cold. A measure of the energy that flows from a hotter to a colder object. Depends on the amount of the substance. Heat is the kinetic energy that flows from a hotter object to a colder one.
Two most common types of biofuels
Bioethanol and biodiesel
What is a bond energy?
Bond energy is the amount of energy that must be absorbed to break a chemical bond or the amount released when a new bond is formed. Breaking bonds is endothermic. Energy is needed.
Which common processes on earth is endothermic? A. the production of oxygen by photosynthesis B. ozone decomposing into O2 in the upper atmosphere C. Water freezing to form ice at 00C D. the reaction of wood with oxygen to form carbon dioxide, water, and ash
Both A and B
Find the molar mass of ethanol, C2H6O A. 29 g/mol B. 45 g/mol C. 46 g/mol D. 110 g/mol
C
How many atoms are present in 0.375 mol of palladium (Pd) atoms? A. 1.61 × 1024 B. 6.02 × 1023 C. 2.26 × 1023 D. 2.12 × 1021
C
How many methane molecules are produced by a cow in a year? A. 14 B. 6.02 x 1023 C. 4.19 x 1027 D. 2.07 x 1028
C
In which example of the entropy of the initial state greater than the entropy of the final state? A building collapses during an earthquake A lump of sugar dissolves into warm water Liquid water freezes into solid ice Liquid water evaporates
C is moving towards more order and has less entropy in the process
What is the equation for the exothermic reaction?
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l) + energy The products are lower in energy than the reactants.
Which country has vast deposits of coal reserves?
China uses a lot of coal for there source of fuel. They are fairly dependent on coal as a source of energy.
This fuel produces the most CO2 per gram Crude oil Coal Natural gas Biodiesel
Coal
This fuel produces the most CO2 per gram. A. Crude oil B. coal C. Natural gas D. Biodiesel
Coal
What is a mole? A measure of the amount of something 6.02 * 10^23 An animal that burrows in the ground All of the above
D
What is required to break bonds?
Energy - endothermic
Which of the following are RENEWABLE resources? A. Energy from solar panels B. Fossil fuels C. Natural gas D. More than one of these are correct
Energy from solar panels
What happens when chemical bonds are formed?
Energy is released - exothermic
What is entropy?
Entropy is a measure of disorder. Natural tendency to become more disordered. Things naturally move towards a less ordered system, more chaos. Requires work and energy to make things less disordered. Requires more energy to get things back into place
2 H2 + O2 > 2H20 Is this exothermic or endothermic?
Exothermic
If the bond-making energy of the products is greater than the bond breaking in the reactants, then the net energy change is...
Exothermic; energy is released in the reaction
TRUE OR FALSE: The transfer of energy can be 100% efficient
FALSE -- energy is definitely conserved but not all of it is useful. Some of it is lost to its surroundings
Where is carbon found on our planet?
Fossil fuels, carbonate minerals in rocks, deep ocean, sand and silt, surface water...
In a refinery, the components of petroleum are separated by A. Combustion reactions B. isomerization C. crystallization D. Fractional distillation
Fractional Distillation
In a refinery, the compoenents of petroleum are separated by Combustion Reactions Isomerization Fractional Distilation
Fractional Distillation Combustion reaction - used to burn fuel. Everything within fuel gets burned. Need to take those products and separate them out, which is what we are during through fractional distillation. Boiling points separate based off of molar masses
The energy that flows from a warmer body to a colder body is called Heat Temperature Potential Work
Heat Heat is a form of energy, a measure of how things are flowing from hot to cold. Also looks at how much of something we have. Amount of heat will be much more in a larger object. Temperature on the other hand is a relative term, looking at how hot or cold something is. Does not depend on how much of something you have.
How is heat used to generate electricity in a modern power plant? A. Heat warms wires causing electrons to move through them more rapidly B. Heat boils water to make steam, which drives a turbine C. Heat warms the fins on a turbine, causing them to spin D. Heat generates strong magnetic fields through which the wires of a turbine move.
Heat boils water to make steam, which drives a turbine
How is heat used to generate electricity in a modern power plant?
Heat boils water to make steam, which drives a turbine Start with potential energy within the fuels, use that to heat up the water *** 2:02
Petroleum (crude oil) is a complex mixture of thousands of substances, the majority of which are: Carbohydrates Hydrocarbons Natural Gases Proteins
Hydrocarbons Separating them out using the distollation tower
Which three words did John Holdren use to summarize our options in dealing with climate change?
Mitigation, adaptation, and suffering
The energy stored in the chemical bonds of fossil fuels is a form of _________ energy Electrical Mechanical Potential Kinetic
Potential We turn potential energy into kinetic energy
List the steps of energy transformations in a fossil fuel electric power plant
Potential energy (fuel molecules) > burner - kinetic energy > turbine - mechanical energy > generator - electrical energy
What is Climate Mitigation?
Ay action taken to permanently eliminate or reduce the long-term risk and hazards of climate change to human life, property, or the environment
A single dairy cow can produce 110 kg of methane per year. How many moles is this? A. 6.9 moles B. 6900 moles C. 176,000 moles D. 6.02 x 1023 moles
B
What are some fuel alternatives?
Biodiesel Ethanol
What else can we do?
Biofuels Solar Energy Wind Energy Nuclear Power
Which common processes on earth is endothermic? The production of oxygen by photosynthesis Ozone decomposing into 02 in the upper atmosphere Water freezing to form ice at 0 degrees C The reaction of wood with oxygen to form carbon dioxide, water, and ash Both A and B
Both A and B (how so??) C and D were exothermic C - going from a liquid to a solid releases energy D - releases energy
What is fracking?
*Watch video
A stable atomic nucleus will remain intact....
....indefinitely
Carbon is found...
...in many places on our planet. Carbon is on the move. Where carbon ends up matters.
Greenhouse gases vary in their effectiveness in absorbing...
...infared radiation
List a few examples of endothermic reactions and why
1 - The decomposition of 03 to 02 and 0 2 - the combination of N2 and O2 to yield two molecules of NO 3 - Photosynthesis Both reactions require energy in the form of an electrical discharge, a high-energy photon, or a high temperature. Basically any chemical or physical change that absorbs energy.
What are the three steps in producing electricity from coal?
1. Burn the coal 2 Use the heat generated from the combustion to boil water. This will result in high pressure steam which will be directed at a steam turbine. 3. As the steam expands and cools, it rushes past the turbine, causing it to spin. The turning of this coil generates and electric current.
What might be handy to know about the carbon cycle?
1. Carbon is found in many places on our planet 2. Carbon is on the move 3. Where carbon ends up matters
Coal is used to create electricity in a power plant - How so? list the three steps
1. Combustion 2. Boil water in a closed, high pressure system 3. Turn turbine to create electricity Taking potential energy from within the fuel, converting to mechanical energy to turn the turbine, and converting into electricity in the end. Through the process we are losing some of the useful energy
Give two reasons why the transfer of energy in a power plant be completely efficient
1. No electric power plant can completely convert one type of energy into another 2. Some of the energy is transferred into useless heat (lost to Universe)
Ethanol (C2H6O) is a common intoxicant and fuel produced from the fermentation of various grains. How many moles of ethanol are represented by 50.0 kg of ethanol? A. 1.09 × 103 mol B. 46.1 mol C. 9.0 mol D. 1.09 mol
1.09*103 mol
Calculate the average mass in grams of an individual atom of nitrogen
14.01 g nitrogen/6.02*10^23 =2.34 *10^-23 g nitrogen/nitrogen atom
What are some of the largest human contributions to CO2 in the atmosphere? A. burning of fossil fuels B. deforestation C. respiration D. Both A and B
Burning of fossil fuels and deforestation
What is an example of something that releases CO2?
Burning wood
Find the molar mass of ethanol, C2H6O
46 g/mol
Calculate the mass in grams of 5 trillion nitrogen atoms
5*10^12 (2.34*10^-23) = 1.17*10^-10
How many joules of heat do you get for every gram of methane?
50.1 = The combustion of methane gas releases 50.1 kJ of energy per gram of CH4.
About how much carbon is released by the human activities of deforestation and the burning of fossil fuels per year?
7.5 Gt per year. Although much of it is recycled by the oceans and the biosphere, not all of it is removed, and about 3.1 to 3.5 Gt of carbon is added to the existing base of 750 Gt in the atmosphere
Calculate the percentage, by mass, of fluorine in sulfur hexafluride (SF6), a potent greenhouse gas
78%
In which example is the entropy of the initial state greater than the entropy of the final state? A. A building collapses during an earthquake B. A lump of sugar dissolves in warm water C. Liquid water freezes into solid ice D. Liquid water evaporates
C. Liquid Water freezes into solid ice
What are the two most common combustion products?
CO2 and H2O, which both contain oxygen
What is a biofuel? Give three examples.
A biofuel is a renewable fuel derived from a biological source, such as trees, grasses, animal waste, or agricultural crops. Examples include wood, charcoal, ethanol, and biodiesel.
As the amount of oxygen in the fuel molecule increases, the heat of combustion
Decreases
As the ratio of hydrogen-to-carbon decreases, the heat of combustion _______
Decreases
The carbon cycle is a .__________ system
Dynamic. These are simultaneous processes, but they happen at different rates.
List different between the endothermic versus exothermic reactions
Endothermic reaction - Energy Products > Energy reactants. The net energy change is positive. Energy is absorbed. Exothermic Reaction - Energy products < energy Reactants. The net energy change is negative. Energy is released.
What is the opposite of exothermic?
Endothermic. We need to put energy in. For example, going from ice to liquid we need to add heat, put energy in. The products are higher in energy than the reactants.
If the energy required to break the bonds in the reactant is greater than the energy released when the products form, the overall reaction is...
Endothermic; energy is absorbed
What is kinetic energy?
Energy of motion. Energy due to the movement of an object. Textbook falling from table. The heavier an object is and the faster it is moving, the more kinetic energy it possesses.
How would you classify the reaction below? HCL + NaOH > H20 + NaCL + Heat Endothermic Exothermic Energy Neutral
Heat is released - shows that this is exothermic.
In an endothermic chemical reaction: The mass of the products is greater than the mass of the reactants The mass of the products is less than the mass of the reactants Heat is released as the reaction proceeds Heat is absorbed as the reaction proceeds
Heat is released as the reaction proceeds
When speaking about energy we are most commonly referring to...
Heat. Also light, as in photosynthesis
What does a good fuel have?
High potential energy. The higher the potential energy of a fuel, the more heat it releases when it is burned to produce CO2 and H2O.
For the endothermic reaction, the products are _____ in energy than the reactants
Higher
Petroleum (crude oil) is a complex mixture of thousands of substances, the majority of which are A. carbohydrates B. hydrocarbons C. natural gases D. proteins
Hydrocarbons
The fuels with the highest heats of combustion are...
Hydrocarbons
Where is most of the carbon on earth stored? In the form of fossil fuels and carbonate minerals and rocks In forests and soil In surface water In the atmosphere
In the form of fossil fuels and carbonate minerals and rocks Issue is that when we burn it and put it into the atmosphere it is not an even exchange In biofuels, although we are still producing carbon dioxide, we recycle it
What is biodiesel?
It is made from natural, renewable sources (vegetable oils, animal fats), and can be used as
What is one drawback to using petroleum?
It must be refined before use (Know Distillation Tower chart)
What are some drawback of using coal?
It produces large amounts of CO2 when burned. Carbon has a long lifetime and takes about 200 years to be taken out of the atmosphere. It also produces nitrogen and sulfur and PM - three of the criteria air pollutants.
What's the problem with CO2?
It stays in the atmosphere. We also put more carbon in the atmosphere than what is removed. Burning fossil fuels and deforestation releases 6.0 - 8.2 Gt/yea
Name the prefixes used for compounds
Mono - 1 Di or bi - 2 Tri - 3 Tetra - 4 Penta - 5 Hexa - 6 Hepta - 7 Octa - 8 Nana - 9 Deca - 10
Coal is made up of... Is it a single compound?
Mostly carbon. It is not a single compound. Coal can be approximated by the chemical formula C135H96O9NS
What is work?
Movement against a force (w = f x d).
What is the net energy change in endothermic and exothermic reactions?
Net energy for endothermic is positive Net energy for exothermic is negative
What serves as carbon sinks?
Oceans and biospheres
Which of the following has the highest boiling point? A. propane B. octane C. methane D. butane
Octane
Which of the following has the highest boiling point? Propane Octane Methane Butane
Octane The boiling point depends on what the compound is and how many carbons there are attached to it the more carbons the heavier it becomes the higher the boiling point is Heat up crude oil everything vaporizes use distillation tower to ***
Of the fuels you listed, which are fossil fuels or derived from them?
Of the fuels listed, the fossil fuels are coal and natural gas. Gasoline, diesel fuel, jet aviation fuel, and petroleum wax are derived from fossil fuels.
What is the chemical name for this structure? -H-C-C-C-C-C-H Octane Pentane Propane Methane
Pentane (Count carbon atoms and go from there) (Know chart)
Does petroleum produce more or less energy than coal?
Petroleum (crude oil/liquid) produces 40-60% more energy per gram than coal
Which processes remove carbon from the atmosphere?
Photosynthesis, absorption in oceans, and reforestation are processes that remove carbon from the atmosphere
What plays an essential role in the carbon cycle?
Photosynthesis. It remomves CO2 from the atmosphere
List five fuels. Name at least two properties that these fuels share.
Possibilities include wood, coal, natural gas, charcoal, gasoline, diesel fuel, jet aviation fuel, petroleum wax, and beeswax. These share properties such as flammability, releasing carbon dioxide and water when burned, and releasing air pollutants when burned. Another possible fuel is hydrogen, but it produces water on combustion (not carbon dioxide).
What is the problem with power plants?
Power plants are inevitably inefficient. It is going against the second law of thermodynamics. We are losing energy to the universe. Taking random, thermal energy and transforming it into ordered work goes against the second law of thermodynamics.
Where does most of the electricity in the US come from?
Primarily coal. About 70% of the electricity generated in the US comes from the burning of fossil fuels - or coal.
Concerns about the enhanced greenhouse effect are based primarily on... However, what other gases play a roll?
Primary concern involves the increases in concentration of atmospheric CO2. However, methane, nitrous oxide, chlorofluorocarbons, and ozone also all take part in trapping heat in our atmosphere
What is temperature?
Relative term. Temperature determines the direction of heat flow. It is a measure of an objects kinetic energy. It tells us how hot or cold an object is relative to another. Does not depends on the amount of a substance. Equations to temperature conversions Temperature is a measure of the average kinetic energy of the atoms and/or molecules present in a substance.
What are 3 criteria air pollutants?
SO2 NO2 PM
TRUE OR FALSE Breaking bonds ALWAYS requires energy
TRUE
Which bond would you expect requires the most energy to break? The O-H bond in water The O=O bond in oxygen gas The C=O bond in acetylene The N---N in Nitrogen Gas
The N---N in nitrogen gas
Which bond would you expect requires the most energy to break? A. The O - H bond in water B. The O = O bond in oxygen gas C. The C = O bond in acetylene D. The N = N in nitrogen gas
The N=-N in nitrogen gas
What is bond energy?
The amount of energy that must be absorbed to break a specific chemical bond
Chemical reactions involve...
The breaking and forming of chemical bonds.
What are the two largest reservoirs of carbon?
The two largest reservoirs of carbon are fossil fuels and carbonate minerals
What is an example of something that absorbes CO2?
Trees
Which step in a powerplant goes against the second law of thermodynamics?
When kinetic energy is transferred into mechanical energy
What is the most common biofuel?
Wood
Of the fuels you listed, which are renewable?
Wood, charcoal, hydrogen, and beeswax are renewable.
Forming bonds releases energy making it....
exothermic. Heat is being released.
For the exothermic reaction, the products are _____ in energy than the reactants
Lower
What is the global atmospheric lifetime? What's another name for this?
The global atmospheric lifetime characterizes the time required for a gas added to the atmosphere to be removed. It is also referred to as the "turnover time."
