FINALS Flashcards
1
Q
the ability to do work or transfer heat
A
energy
2
Q
the study of energy and its transformation
A
thermodynamics
3
Q
the study of chemical reactions and the energy changes that involve heat
A
thermochemistry
4
Q
seen between oppositely charged ions
A
electrostatic attraction
5
Q
chemical bonds are formed
A
energy is released
6
Q
when chemical bonds are broken
A
energy is consumed
7
Q
can be converted from one form to another, but it is neither created nor destroyed
A
energy
8
Q
portion of the universe that we single out study
A
system
9
Q
are everything else
A
surroundings
10
Q
TYPES OF SYSTEM
A
Open, Closed, Isolated
11
Q
can exchange heat and mass with its surroundings
A
open system
12
Q
can only exchange heat with its surroundings
A
closed system
13
Q
can not exchange heat or mass with its surroundings
A
isolated system
14
Q
system is the sum of all kinetic and potential energies of all components
A
internal energy
15
Q
system absorbed energy from the surroundings.
A
ΔE > 0, Efinal > Einitial
16
Q
the system released energy to the surroundings.
A
ΔE < 0, Efinal < Einitial
17
Q
What is the value of ΔE if Efinal equals Einitial?
A
zero
18
Q
three parts of thermodynamic quantities
A
number, unit, sign
19
Q
the system gains energy from the surroundings.
A
A positive ΔE
20
Q
the system loses energy to the surroundings.
A
negative ΔE
21
Q
change of internal energy is:
A
ΔE = q + w
22
Q
heat is absorbed by the system from the surroundings
A
endothermic
23
Q
heat is released by the system into the surroundings
A
exothermic
24
Q
internal energy is a
A
state function
25
change of internal energy depends on the
initial and final internal energy
26
the only work done by chemical or physical change is
mechanical work
27
what is the formula of work
w = -PΔV
28
work done by the system
work is negative
29
the internal energy plus the product of pressure and volume
enthalphy
30
formula of enthalphy is
H = E+PV
31
the change in enthalphy is the heat gained or lost
at constant pressure
32
a process is ____ when change of enthalphy is positive
endothermic
33
A process is_____when ΔH is negative.
exothermic
34
the formula of change in enthalphy
ΔHrxn = Hproducts − Hreactants
35
ΔHrxn
enthalpy of reaction, or the heat of reaction.
36
an extensive property
enthalphy
37
the enthalphy change for a reaction is equal in __ but opposite in sign
magnitude
38
the enthalpy change for the reaction in which a compound is made from its constituent elements in their elemental forms.
enthalphy of formation
39
The enthalpy associated with breaking one mole of a particular bond in a gaseous substance.
bond enthalphy
39
the bond enthalphy is always ___ because energy is required to break chemical bonds
positive
39
always released when a bond forms
energy
40
the greater the bond enthalphy
the stronger the bond
41
the measurement of heat flow
calorimetry
42
instrument used to measure heat flow
calorimeter
43
amount of energy required to raise the temperature of a substance
heat capacity
44
energy released when one gram of food is combusted
fuel value
45
composed of the two nucleons, protons and neutrons
nucleus
46
is the atomic number
number of protons
47
the number of protons and neutrons together
mass number
48
not all atoms of the same element have the same mass due to different numbers of neutrons in those atoms
isotopes
49
Some nuclei change spontaneously, emitting radiation. They are said to be
radioactive
49
three naturally occuring isotopes of uranium
Uranium 234, 235, 238
50
We use nuclear equations to show
how these nuclear reactions occur.
51
atoms and charges need to balance
In chemical equations
52
the loss of a γ-ray, which is high-energy radiation
gamma emission
52
atomic number and mass number need to balance
In nuclear equations
53
Types of Radioactive Decay
Alpha decay
Beta decay
Gamma emission
Positron emission
Electron capture
54
the loss of an α-particle (He-4 nucleus, two protons and two neutrons):
Alpha decay
54
the loss of a β-particle (a high-speed electron emitted by the nucleus
Beta Decay
55
a particle that has the same mass as, but an opposite charge to, that of an electron:
positron emission
56
some nuclei decay by emitting a
positron
57
An electron from the surrounding electron cloud is absorbed into the nucleus during
Electron Capture
58
What change in the mass number of a nucleus occurs when the nucleus emits an alpha particle?
-4
59
Which type of radioactive decay converts a neutron into a proton?
Beta Decay
60
is the time required for half of a radionuclide sample to decay.
half-life
61
are radioisotopes used to study a chemical reaction.
radiotracers
62
react chemically exactly the same as nonradioactive nuclei of the same element.
radionuclides
63
A compound labeled with a positron emitter is injected into a patient.
Positron emission tomography
64
is used to study the brain, as seen in the figure to the right.
labeled glucose
65
einstein's famous equation is
E = mc^2
66
is associated with making and breaking chemical bonds.
chemical energy
67
is due to changes in the nucleus of atoms changing them into different atoms
nuclear energy
68
released in the transmutation strike other nuclei, causing their decay and the production of more neutrons
neutrons
69
The minimum mass that must be present for a chain reaction to be sustained
critical mass
70
If more than critical mass is present, an explosion will occur
supercritical mass
71
When small atoms are combined, much energy is released. This occurs on the Sun. The reactions are often called
thermonuclear reactions
72
is more harmful to living systems than nonionizing radiation
ionizing radiation
73
the study of the relationships between electricity and chemical reactions.
electrochemistry
74
To keep track of what loses electrons and what gains them
oxidation numbers
75
If the oxidation number increases for an element, that element is
iodized
76
If the oxidation number decreases for an element, that element is
reduced
77
A species is ____ when it loses electrons
oxidized
78
A species is____ when it gains electrons.
reduced
79
In spontaneous redox reactions, ____ are transferred and ______ is released.
electrons, energy
80
energy can do work if the electrons flow through an external device.
voltaic cell
81
The oxidation occurs at the
anode.
82
The reduction occurs at the
cathode
83
In the cell, _____ leave the anode and flow through the wire to the ______
electrons, cathode
83
As the electrons reach the cathode, ______ in solution are attracted to the now _____ cathode.
cations, negative
83
electromotive force is also called
cell potential
83
are formed in the anode compartment.
cation
84
The potential difference between the anode and cathode in a cell
electromotive force (emf)
84
the greater the tendency for reduction under standard conditions.
The more positive the value of E°red
84
electromotive force is measured in ?
volts (V)
85
have the most positive reduction potentials
the strongest oxidizers
86
have the most negative reduction potentials
the strongest reducers
87
Notice that the Nernst equation implies that a cell could be created that has the same substance at both electrodes,
concentration cell
88
cannot be recharged when “dead”—the reaction is complete
primary cells
88
the measure of spontaneity, positive emf corresponds to negative ΔG.
Gibbs free energy
88
a portable, self-contained electrochemical power source that consists of one or more voltaic cells
batteries
88
can be recharged
secondary cells
89
reactants and products are solids
Lead- acid battery
90
most common primary battery
alkaline battery
91
kinds of batteries that are lightweight and rechargeable
Ni-Cd and Ni-metal hybride batteries
92
Cd is considered as ?
toxic and heavy
93
rechargeable, light; produce more voltage than Ni-based batteries.
Lithium- ion batteries
94
The direct conversion of chemical to electrical energy is expected to be more efficient and is the basis for
fuel cells
94
When a fuel is ____, the energy created can be converted to electrical energy.
burned
95
fuel batteries are not batteries
true
96
corrosion is
oxidation
97
common name of corrosion is
rusting
97
occurs because zinc is more easily oxidized
Cathodic protection
97
is attached to the pipe. The anode is oxidized before the pipe.
Sacrificial Anode
97
Nonspontaneous reactions can occur in electrochemistry IF _____ electricity is used to drive the reaction.
outside
97
Use of electrical energy to create chemical reactions is
electrolysis
97
the least weighty part of the environment, but it is complex and has a disproportionately large influence on our planet.
atmosphere
97
total mass of the atmosphere is estimated to be around
5.15 x 10^18 kg
98
arose from the out-gassing of Earth when it was simply a molten mass
nitrogen
98
is not the direct source of this element in living beings
Gaseous N2
98
nitrogen must be in the form of a usable nitrogen compound, such as
ammonia, ammonium or nitrate ions
99
who are the two geman chemists who devised a way to transform nitrogen in the air into fertilizer?
Fritz Haber and Carl Bosch
100
The nitrogen cycle involves nitrogen fixation by soil bacteria or, in aquatic environments, by
cyanobacteria
101
ions produced are converted to nitrate ions, the main form of nitrogen absorbed by plants
NH4+
101
is the second most abundant species present in the atmosphere.
O2
102
is by-product of plant photosynthesis
oxygen
102
first began producing oxygen as long ago as 3.5 billion years.
Blue-green algae, or cyanobacteria
103
Nitrogen is returned to the atmosphere by ____ which convert nitrate ions to n2
denitrifying bacteria
104
a microbial process by which reduced nitrogen compounds (primarily ammonia) are sequentially oxidized to nitrite and nitrate.
Nitrification
104
a chemical process that intends to “lock” tissue, cells, and subcellular components as close as possible to its original status
Fixation
105
acts as a shield from the UV- rays in stratosphere
Ozone (O3)
105
it is also a pollutant in troposphere
Ozone (O3)
105
The leakage of chlorofluorocarbons CFCs in refrigerators and other domestic appliance causes the depletion of ozone layer.
ozone hole
106
the two molecule are
CFC-114 (C2Cl2F4) and CFC-12 (CCl2F2)
106
CFC 114
Dichlorotetrafluoroethane
106
CFC-12 (CCl2F2)
Dichlorodifluoromethane
106
has the ability to form stable compounds consisting of long chains and rings of atoms.
carbon
107
the basis of the structures for many compounds that comprise the living cell.
carbon
108
The food we eat—carbohydrates, oils, proteins, and fiber—is made up of compounds of
carbon
108
name given to the trapping of energy in the Earth’s atmosphere by a process very similar to that occurring in glass-enclosed greenhouses in which plants are grown
greenhouse effect
109
The greenhouse effect is caused by certain gases in the troposphere called
greenhouse gases
110
These gases are small molecules whose bonds vibrate with frequencies in the infrared region of the electromagnetic spectrum (resonance phenomena).
greenhouse gases
111
primary greenhouses gases are:
Water vapor H2O
Carbon dioxide CO2
Nitrous oxide N2O
112
the main greenhouse gas and accounts for most of the observed effect.
water vapor
112
a comprehensive air quality management policy and program which aims to achieve and maintain healthy air for all Filipinos.
Republic Act No. 8749 or Philippine Clean Air Act
112
is a multi-sectoral undertaking to be spearheaded by the Department of Environment and Natural Resources (DENR).
Implementation of the Act
113
