Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

AP Chemistry > Chapter 5: energy, heat, and work > Flashcards

Chapter 5: energy, heat, and work Flashcards

1
Q

a complete chemical equation includes a quantitative measure of the

A

energy produced or consumed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

thermochemistry is the study of the

A

relationship between heat and chemical reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

all forms of energy fall into two categories:

A

kinetic energy and potential energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

kinetic energy is energy possessed by matter because it is

A

in motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the kinetich energy of an object depends on both its

A

mass (m) and its velocity (v)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

kinetic energy =

A

1/2m * v^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The SI unit for energy is the

A

joule (J)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

joule=

A

[(kilogram)(meter)^2] / (second)^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

thermal energy is kinetic energy in the form of

A

random motion of the particles in a sample of matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the greater the temperature of the matter, the … its particles move and the …

A

faster; higher its thermal energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

heat is the flow of energy from … that causes a change in the …

A

one object to the other; temperature of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when heat is added to or removed from a sample, it causes a change in the

A

temperature of that sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

work is the application of a

A

force across some distance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

it takes energy to perform .., so like heat, quantities of .. are expressed in units of …

A

work; work; joules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

work can take many forms: … work, … work, … work, … work, and … work

A

mechanical; chemical; gravitational; pressure-volume; electrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

potential energy is energy possessed by matter because of its

A

position or condition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

…. energy: compounds also possess … as a result of the …

A

chemical; potential energy; forces that hold the atoms together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

in a chemical reaction, because the chemical energy of the reactants is not the same as that of the products, enrgy is either … or … during the reaction, usually in the form of …

A

absorbed; released; heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

system:

A

sample of matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the system is the matter of

A

interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

the surroundings are

A

all other matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

surroundings include the

A

reaction container

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

law of conservation of energy states that the total energy of the … is … during a …

A

universe; constant; chemical/physical change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

universe:

A

system + surroundings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
energy is often ... the system and the surrooundings
transferred between
26
law of conservation of energy is also referred to as the
first law of thermodynamics
27
if energy transfers between the system and the surroundings, then the total amount of energy contained in the system has
changed
28
energy change =
work + heat
29
exothermic: ... to the surroundings
releases heat
30
endothermic: a reaction that
absorbs heat
31
energy can be considered a
reactant/product
32
SI unit of heat energy is
joule
33
a calorie was originally defined as the amount of heat needed to increase the .... by ..., from .. to ...
temperature of 1 g water; 1 degree celsius; 14.5 degrees C to 15.5 degrees C
34
1 cal =
4.184 J
35
thus, it takes ... J to increase the temperature of 1 g water from 14.5 degrees celsius to 15.5 degrees celsius
4.184 J
36
enthalpy, H, of a system is the measure of the
total energy of the system at a given pressure and temperature
37
enthalpy cannot be measured, but the ... that accompanies a change in the system can be measured
change in enthalpy
38
under conditions of constant pressure and temperature, the quanitity of heat ... at constant temperature and pressure is called the
absorbed/given off by the system; change in enthalpy
39
delta H means
Hfinal - Hinitial
40
if the chemical reaction is exothermic, the system has ..., which means that its enthalpy ... and delta H is ..
lost energy; decreases; negative
41
if the chemical reaction is endothermic, the enrgy of the system ... and the sign of delta H is ...
increases; positive
42
a thermochemical equation is a chemical equation for which
the value of delta H is given
43
the chemical reaction is assumed to occur at .., because delta H is used in the thermochemical equation
constant pressure and temperature
44
the enthalpy is determined by
experiment
45
in a thermochemical equation, delta H assumes that the coefficients refer to
molar quantities
46
it is important to include the ... of every substance in any ...
physical state; thermochemical equation
47
enthalpy changes are part of the ... of a thermochemical equation
Stoichiometry
48
the thermochemical equation expresses the stoichiometric relationship between the ... of any substance in the equation and the ...
number of moles; quantity of heat produced or absorbed in the reaction
49
calorimetry: measurement of the heat ... when the ... occurs
released or absorbed; chemical change
50
calorimeter: the device in which the ... and the ...
reaction takes place; heat is meausred
51
the quantity of heat released or absorbed by the reaction causes a change in the .... which is measured with a ...
temperature of the solution; thermometer
52
for the heat to correspond to the enthalpy change of the system, the calorimeter must be operated at
constant pressure
53
the reaction in the calorimeter proceeds at constant pressure because .. changes little during the course of the experiment
atmospheric pressure
54
the insulation provided by the calorimeter prevents any
transfer of heat into or out of the calorimeter
55
in a calorimetry experiment, the amount of solution must be known because the observed temperature change depends on the
amount of solution present
56
the heat capacity of a sample is the quantity of heat required to
increase the temperature of that object by 1 K
57
heat capacity has units of ... or ..., and is nearly constant for a given substance over...
J/K; J/ degrees C; small ranges of temperature
58
the specific heat is the heat needed to ...
increase the temperature of a 1-g sample of the material by 1 K
59
1 =
m*Cs*deltaT
60
q is
heat in joules
61
m is
mass in grams
62
Cs is
specific heat of sample
63
(assumptions in calorimetry calculations) the heat required to change the temperature of the vessel, stirrer, and thermometer is
sufficiently small to be ignored
64
(assumptions in calorimetry calculations) the specific heat of the solution, as long as it is dilute, is the
same as that of water, 4.184 J/gK
65
a state function is any ... that is determeined by the ..
property of a system; present conditions of the system
66
the state function is independent of how the
system got to that set of conditions
67
the enthalpy, and the change in enthalpy, of a chemical system is a
state function
68
the value of delta H for a process does not depend on how the
process occurred
69
the delta H is only dependent of the ... of the system and the ... of the system
initial state; final state
70
in thermochemical equations, the coefficients refer to molar amounts, so
fractional coefficents can be used
71
energy-level diagrams are ... graphs
one-dimensional
72
an energy-level diagram is a representation of the relative ... of the ...
enthalpies; reactnats and products of a reaction
73
reversing the direction of a chemical reaction ... on the reaction's deltaH
changes the sign
74
Hess's law: calculating the enthalpy change in an overall chemical reaction by
summing the enthalpy changes of each step
75
the properties that govern the combination of thermochemical equations are natural consequences of ... and the fact that ...
the law of conservation of energy; enthalpy is a state function
76
the change in enthalpy for an equation obtained by adding two or more thermochemical equations is the sum of the
enthalpy changes of the added equations
77
the enthalpy change is an ... that depends on the amounts of the substances that react
extensive
78
hess's law lets us calculate the enthalpy change for one reaction from
thermochemical equations for others
79
enthalpy change for any reaction is influenced by the
pressure and the temperature
80
standard state of a substance is the ... at ... and the ...
pure form; one atmosphere pressure; designated temperature (usually 298.15 K or 25.0 degrees C)
81
standard enthalpy change is an enthalpy change in which all
reactants and products are in their standard states
82
the symbol for standard enthalpy change is
ΔH°
83
° means that all reactants and products are in the standard state of
1 atm pressure and 298.15 K
84
a formation reaction is a chemical reaction that makes
one mole of a substane from its constituent elements in their standard states
85
the enthalpy change for a formation reaction is symbolized by
ΔHf°
86
the subscript f stands for
formation
87
ΔHf° is called
standard enthalpy of formation
88
the ΔHf° of all elements in their standard states is
zero
89
ΔH°rxn =
∑mΔHf° [products] - ΣnΔHf° [reactants]
90
m is the number of moles of each
product
91
n is the number of moles of each
reactant
92
the reactants contribute the ... of their enthalpies of formation, whears products contribute the ... of their enthalpies of formation
negative; positive
93
enthalpy of combustion: the energy change for a ...
combustion reaction

AP Chemistry (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions