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76 Cards in this Set

  • Front
  • Back
there are losses everytime energy is transformed, no power plant can be
100% efficient
biofuel was mostly what until recently
wood!
what is biofuel= a renewable resource
since about 1950 what has been the #1 energy/ fuel type consumed
petroleum
70% of the electricity generated in the US comes from what
burning fossil fuels, primarily coal.
combustion
the chemical process of burning; that is, the rapid combination of fuel with oxygen to release energy in the form of heat and light
potential energy
stored energy or the energy of position. ex: when you hold a book up in the air the higher you hold it and the heavier the book the higher the potential energy
kinetic energy
the energy in motion. the heavier an object us and the faster it is moving the more kinetic energy it posses.
the process of combustion converts some of the potential energy of fuel molecules into heat, which in turn is absorbed by water in the boiler
molecules with high potential energy make good fuels.
law of conservation of energy says that energy can neither be created nor destroyed. what does that mean?
(first law of thermodynamics) although the forms of energy change, the total amount of energy before and after any transformation remains the same.
the solar energy that is stored as potential energy during photosynthesis is released as
heat and light during combustion (look at 4.4 p 158)
a calorie
the amount of heat necessary to raise the temperature of one gram of water by one degree celsius.

1 kilocalorie= 1000 calories (cal)=1 Calorie (Cal)
joule
a unit of energy equal to .239 cal
entropy
a measure of how much energy gets dispersed in a given process
second law of thermodynamics
that the entropy of the universe is constantly increasing.
which continent uses the most coal?
ASIA and then N america
what is the lowest grade of coal?
Soft lignite or brown coal
high contents of carbon and low contents of sulfur are
the most desirable grade of coal (anthracite)
4 drawbacks of coal
1. underground mining. it is dangerous and expensive.
2. environmental harm caused by coal mining. ruining water in streams and rivers.
3. dirty fuel. soot blackens lungs and buildings. tons of mercury is released into the environment each year.
4. burning coal produces carbon dioxide (greenhouse gas)
petroleum is a mixture of thousands of different compounds. one of them being hydrocarbon (most abundant) what is a hydrocarbon?
compounds that consist only of the elements hydrogen and carbon.
hydrocarbons can contain from 1 to 60 atoms per molecule. many of those molecules are alkanes. what is an alkane?
hydrocarbons with only single bonds between carbon atoms.
what provides heat for about two thirds of single family homes in the US
natural gas
what is energy?
is the capacity to do work or supply heat
what is WORK?
is done when movement occurs against a restraining force
W=FxD
power
is work per unit of time

P=WxT
temperature
a measure of the average kinetic energy of the atoms and or molecules present in a substance
device used to measure quantity of heat energy released in a combustion reaction
calorimeter
heat of combustion p. 173 for example
the quantity of heat energy given off when a specified amount of a substance burns in oxygen

energy of reactants---> energy difference (heat released)---> energy of products
what is an aquifer?
a great pool of water trapped below the Earth's surface in sand and gravel.
Of the salts sodium sulfate (Na2SO4), ammonium nitrate, (NH4NO3), aluminum hydroxide (Al(OH)3), and sodium chloride (NaCl), which are soluble in water?
Na2SO4, NH4NO3, and NaCl only
rank these covalent bonds in order of increasing polarity.
H—S < H—N < H—O
When a 0.1 M solution of ethanol, C2H5OH, in water is tested for conductivity using the type of apparatus shown the light bulb will ______________; ethanol is _____________.
not light up; in molecular form in aqueous solution.
When sodium nitrate, NaNO3, dissolves in water,
ions of Na+ and NO3- are formed in the polar solvent.
the correct formula and charge for the sulfite ion is _______.
SO3^2-
When NaCl dissolves in water the structure of the solution is best described as
Na+ cations surrounded by the oxygen atoms of several water molecules, and Cl¯ anions surrounded by the hydrogen atoms of several water molecules.
A chloride ion contains _________ protons, ________ electrons, and has a net charge of ________.
17, 18, 1-
How many moles of NaCl are there in 250 mL of a 1.20 M aqueous solution of NaCl?
.30 mol
Based on the number of electron pairs around the central oxygen atom in a water molecule the predicted H-to-O-to-H bond angle is
109.5 degrees
a hydrogen bond is not as strong as what?
any bond in an actual molecule
which one of the following is not a major use of fresh water: thermal electric power generation, wind turbines, irrigation, domestic consumption
wind turbines
three true statements about solutions
a solution is a homogeneous mixture of uniform composition
solutes are substances that dissolve in a solvent
a solvent is a substance that is capable of dissolving other substances
what is the chemical formula for the ionic compound sodium oxide?
Na2O
M (molarity)=
moles/liters
ions
if you lose one (or more) your positive if you gain one (or more) your negative
Which is characteristic of a solution?
The solute cannot be separated from the solvent by simple filtration.
What is the molarity of a solution containing 3.5 moles of HCl in 5.0 L of water?
0.70 M
A calcium ion contains ______ protons, ________ electrons, and has a net charge of ______.
20, 18, 2+ (it loses two to be like Ar so that makes it positive 2)
"Like dissolves like" implies that
solvents dissolve solutes that have similar polarity.
Based on trends within the periodic table, which element is expected to have the greatest tendency to attract bonded electrons?
Li
O
Se
Rb
O
Beer is a complex aqueous solution. For example, one liter of a certain beer contains 62 g of ethanol. What is the approximate molarity of ethanol in this beer?
train tracks- 1.3M (M=moles/liters)

62 g divided by molar mass of ethanol (C2H6O)
Which is the most polar bond?
O—H
The correct formula and charge for the nitrate ion is _______.
NO3-
1 joule
is the work done by a force of one Newton (N) acting through a distance of one meter
a newton
is the force required to cause a mass of 1 kilogram to accelerate at a rate of 1 m/s2 in the absence of other force-producing effects.
1 calorie
is roughly (it used to be exactly) the amount of heat needed to raise the temperature of one gram of water by 1 oC
Heat used x efficiency = heat needed
Heat used x 0.34 = 3.5 x 107 kJ; therefore, heat used = 1.0 x 108 kJ
on slides from lecture 11
Which equation represents cracking, the production of more useful molecular weight fractions from crude oil?
C16H34 + catalyst → C8H18 + C8H16
How much energy will be required to break the bonds in one mole of nitrogen gas, N2?
946 kJ (because it is a triple bond, because there are more than 10 valence electrons)
Which equation represents the complete combustion of a hydrocarbon?
C2H4(g) + 3 O2(g) ----> 2 CO2(g) + 2 H2O (g) + heat
The Law of Conservation of Energy (energy is neither created nor destroyed in a chemical reaction) is also known as the
First Law of Thermodynamics.
One serving of a snack labeled as providing 150 Cal per serving provides _______ kJ?
630 (150 times 4.2 which is the amount of kj per calorie)
Fossil fuels
originated as plant or animal matter 150-300 million years ago. They are nonrenewable resources.
Bond formation always _______ energy; it is an ________ process.
releases, exothermic
Which is not a fossil fuel?
coal
petroleum
uranium
natural gas
uranium
The energy that flows from a warmer object to a cooler object is called
heat.
As of 2008, the major end use of crude oil in the U.S. is
gasoline.
Compared to gasoline made from pure hydrocarbons, oxygenated gasoline has a ______ octane rating, results in ___________ complete combustion, and releases ______ energy per gram?
higher, more, less
The heat energy absorbed or released by a chemical reaction is determined by the difference between the energy __________ to break the bonds in the reactants and the energy ________ upon making the bonds in the products.
required, released
Explosives are chemicals that give off a great deal of heat (and often gas) when detonated. Reactions in which reactant molecules have _________ bonds and product molecules have ______ bonds release the most energy.
weak, strong
Power plants generate electricity by harnessing the energy stored in chemical bonds. Which lists, in the correct order, the forms that the energy takes to get from a fossil fuel to an electrical outlet?
potential energy → heat energy → mechanical energy → electrical energy
Reformulated gasolines contain ________ and were developed to meet __________.
oxygen-containing compounds, mandates of the Clean Air Act and its amendment
Gasohol is a mixture of ethanol and petroleum-based products that can be used as an alternative fuel for cars. Which statements are considered disadvantages for increased use of gasohol?
Use of corn for fuel may limit the availability of corn for food.
III. Complete combustion of gasohol produces greenhouse gases.
As of 2008 in the U.S. the two energy sources that contribute almost equally to our total energy use are
coal and natural gas.
isomers
same molecules, but different formations
electronegativity
the power of an atom, in a molecule, to attract electrons to itself."
inert gasses
the last row of gases (he, Ne<ar, etc)
do not have electronegativity values because they do not form bonds to other atoms.
what is all true about petroleum
(a) We already know how to use it. (B) It has a high energy content. (C) It is easy to store and transport. (D) It emits CO2 when used to generate energy.