Chem Exam 2

Front 1

there are losses everytime energy is transformed, no power plant can be

Back 1

100% efficient

Front 2

biofuel was mostly what until recently

Back 2

wood!
what is biofuel= a renewable resource

Front 3

since about 1950 what has been the #1 energy/ fuel type consumed

Back 3

petroleum

Front 4

70% of the electricity generated in the US comes from what

Back 4

burning fossil fuels, primarily coal.

Front 5

combustion

Back 5

the chemical process of burning; that is, the rapid combination of fuel with oxygen to release energy in the form of heat and light

Front 6

potential energy

Back 6

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

Front 7

kinetic energy

Back 7

the energy in motion. the heavier an object us and the faster it is moving the more kinetic energy it posses.

Front 8

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

Back 8

molecules with high potential energy make good fuels.

Front 9

law of conservation of energy says that energy can neither be created nor destroyed. what does that mean?

Back 9

(first law of thermodynamics) although the forms of energy change, the total amount of energy before and after any transformation remains the same.

Front 10

the solar energy that is stored as potential energy during photosynthesis is released as

Back 10

heat and light during combustion (look at 4.4 p 158)

Front 11

a calorie

Back 11

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)

Front 12

joule

Back 12

a unit of energy equal to .239 cal

Front 13

entropy

Back 13

a measure of how much energy gets dispersed in a given process

Front 14

second law of thermodynamics

Back 14

that the entropy of the universe is constantly increasing.

Front 15

which continent uses the most coal?

Back 15

ASIA and then N america

Front 16

what is the lowest grade of coal?

Back 16

Soft lignite or brown coal

Front 17

high contents of carbon and low contents of sulfur are

Back 17

the most desirable grade of coal (anthracite)

Front 18

4 drawbacks of coal

Back 18

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)

Front 19

petroleum is a mixture of thousands of different compounds. one of them being hydrocarbon (most abundant) what is a hydrocarbon?

Back 19

compounds that consist only of the elements hydrogen and carbon.

Front 20

hydrocarbons can contain from 1 to 60 atoms per molecule. many of those molecules are alkanes. what is an alkane?

Back 20

hydrocarbons with only single bonds between carbon atoms.

Front 21

what provides heat for about two thirds of single family homes in the US

Back 21

natural gas

Front 22

what is energy?

Back 22

is the capacity to do work or supply heat

Front 23

what is WORK?

Back 23

is done when movement occurs against a restraining force
W=FxD

Front 24

power

Back 24

is work per unit of time

P=WxT

Front 25

temperature

Back 25

a measure of the average kinetic energy of the atoms and or molecules present in a substance

Front 26

device used to measure quantity of heat energy released in a combustion reaction

Back 26

calorimeter

Front 27

heat of combustion p. 173 for example

Back 27

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

Front 28

what is an aquifer?

Back 28

a great pool of water trapped below the Earth's surface in sand and gravel.

Front 29

Of the salts sodium sulfate (Na2SO4), ammonium nitrate, (NH4NO3), aluminum hydroxide (Al(OH)3), and sodium chloride (NaCl), which are soluble in water?

Back 29

Na2SO4, NH4NO3, and NaCl only

Front 30

rank these covalent bonds in order of increasing polarity.

Back 30

H—S < H—N < H—O

Front 31

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 _____________.

Back 31

not light up; in molecular form in aqueous solution.

Front 32

When sodium nitrate, NaNO3, dissolves in water,

Back 32

ions of Na+ and NO3- are formed in the polar solvent.

Front 33

the correct formula and charge for the sulfite ion is _______.

Back 33

SO3^2-

Front 34

When NaCl dissolves in water the structure of the solution is best described as

Back 34

Na+ cations surrounded by the oxygen atoms of several water molecules, and Cl¯ anions surrounded by the hydrogen atoms of several water molecules.

Front 35

A chloride ion contains _________ protons, ________ electrons, and has a net charge of ________.

Back 35

17, 18, 1-

Front 36

How many moles of NaCl are there in 250 mL of a 1.20 M aqueous solution of NaCl?

Back 36

.30 mol

Front 37

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

Back 37

109.5 degrees

Front 38

a hydrogen bond is not as strong as what?

Back 38

any bond in an actual molecule

Front 39

which one of the following is not a major use of fresh water: thermal electric power generation, wind turbines, irrigation, domestic consumption

Back 39

wind turbines

Front 40

three true statements about solutions

Back 40

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

Front 41

what is the chemical formula for the ionic compound sodium oxide?

Back 41

Na2O

Front 42

M (molarity)=

Back 42

moles/liters

Front 43

ions

Back 43

if you lose one (or more) your positive if you gain one (or more) your negative

Front 44

Which is characteristic of a solution?

Back 44

The solute cannot be separated from the solvent by simple filtration.

Front 45

What is the molarity of a solution containing 3.5 moles of HCl in 5.0 L of water?

Back 45

0.70 M

Front 46

A calcium ion contains ______ protons, ________ electrons, and has a net charge of ______.

Back 46

20, 18, 2+ (it loses two to be like Ar so that makes it positive 2)

Front 47

"Like dissolves like" implies that

Back 47

solvents dissolve solutes that have similar polarity.

Front 48

Based on trends within the periodic table, which element is expected to have the greatest tendency to attract bonded electrons?
Li
O
Se
Rb

Back 48

O

Front 49

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?

Back 49

train tracks- 1.3M (M=moles/liters)

62 g divided by molar mass of ethanol (C2H6O)

Front 50

Which is the most polar bond?

Back 50

O—H

Front 51

The correct formula and charge for the nitrate ion is _______.

Back 51

NO3-

Front 52

1 joule

Back 52

is the work done by a force of one Newton (N) acting through a distance of one meter

Front 53

a newton

Back 53

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.

Front 54

1 calorie

Back 54

is roughly (it used to be exactly) the amount of heat needed to raise the temperature of one gram of water by 1 oC

Front 55

Heat used x efficiency = heat needed
Heat used x 0.34 = 3.5 x 107 kJ; therefore, heat used = 1.0 x 108 kJ

Back 55

on slides from lecture 11

Front 56

Which equation represents cracking, the production of more useful molecular weight fractions from crude oil?

Back 56

C16H34 + catalyst → C8H18 + C8H16

Front 57

How much energy will be required to break the bonds in one mole of nitrogen gas, N2?

Back 57

946 kJ (because it is a triple bond, because there are more than 10 valence electrons)

Front 58

Which equation represents the complete combustion of a hydrocarbon?

Back 58

C2H4(g) + 3 O2(g) ----> 2 CO2(g) + 2 H2O (g) + heat

Front 59

The Law of Conservation of Energy (energy is neither created nor destroyed in a chemical reaction) is also known as the

Back 59

First Law of Thermodynamics.

Front 60

One serving of a snack labeled as providing 150 Cal per serving provides _______ kJ?

Back 60

630 (150 times 4.2 which is the amount of kj per calorie)

Front 61

Fossil fuels

Back 61

originated as plant or animal matter 150-300 million years ago. They are nonrenewable resources.

Front 62

Bond formation always _______ energy; it is an ________ process.

Back 62

releases, exothermic

Front 63

Which is not a fossil fuel?
coal
petroleum
uranium
natural gas

Back 63

uranium

Front 64

The energy that flows from a warmer object to a cooler object is called

Back 64

heat.

Front 65

As of 2008, the major end use of crude oil in the U.S. is

Back 65

gasoline.

Front 66

Compared to gasoline made from pure hydrocarbons, oxygenated gasoline has a ______ octane rating, results in ___________ complete combustion, and releases ______ energy per gram?

Back 66

higher, more, less

Front 67

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.

Back 67

required, released

Front 68

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.

Back 68

weak, strong

Front 69

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?

Back 69

potential energy → heat energy → mechanical energy → electrical energy

Front 70

Reformulated gasolines contain ________ and were developed to meet __________.

Back 70

oxygen-containing compounds, mandates of the Clean Air Act and its amendment

Front 71

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?

Back 71

Use of corn for fuel may limit the availability of corn for food.
III. Complete combustion of gasohol produces greenhouse gases.

Front 72

As of 2008 in the U.S. the two energy sources that contribute almost equally to our total energy use are

Back 72

coal and natural gas.

Front 73

isomers

Back 73

same molecules, but different formations

Front 74

electronegativity

Back 74

the power of an atom, in a molecule, to attract electrons to itself."

Front 75

inert gasses

Back 75

the last row of gases (he, Ne<ar, etc)
do not have electronegativity values because they do not form bonds to other atoms.

Front 76

what is all true about petroleum

Back 76

(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.