Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chem > chemical thermodynamics > Flashcards

chemical thermodynamics Flashcards

1
Q

What is the first law of thermodynamics?

A

Energy cannot be created or destroyed, only converted from one form to another.

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

Define internal energy.

A

The total energy contained within a system, including kinetic and potential energy of molecules.

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

What is heat?

A

The transfer of energy due to a temperature difference.

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

What is work?

A

Energy transfer due to a force acting over a distance.

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

What is work of expansion?

A

Work done by the system when it expands against external pressure.

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

What is enthalpy?

A

The heat content of a system at constant pressure.

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

Define standard enthalpy.

A

The enthalpy change when one mole of a substance is formed from its elements in their standard states.

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

What is enthalpy of formation?

A

The enthalpy change when one mole of a compound is formed from its elements in their standard states.

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

What is enthalpy of combustion?

A

The enthalpy change when one mole of a substance burns in excess oxygen.

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

What is enthalpy of neutralization?

A

The enthalpy change when one mole of an acid reacts with one mole of a base to form water.

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

What is enthalpy of atomization?

A

The enthalpy change when one mole of atoms is formed from the element in its standard state.

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

What are the laws of thermochemistry?

A

1) The heat evolved or absorbed in a reaction is the same whether it takes place in one step or several steps. 2) The heat evolved or absorbed in a reaction is proportional to the quantities of the reactants.

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

What is bond enthalpy?

A

The energy required to break one mole of bonds in gaseous molecules.

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

What is the second law of thermodynamics?

A

The entropy of an isolated system always increases over time.

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

Define enthalpy change (ΔH).

A

The heat absorbed or released at constant pressure.

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

What is the formula for work in thermodynamics?

A

W = -PΔV, where P is the pressure and ΔV is the change in volume.

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

What is the formula for heat capacity (C)?

A

C = q / ΔT, where q is heat absorbed and ΔT is temperature change.

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

What is specific heat capacity?

A

The heat required to raise the temperature of 1 gram of a substance by 1°C.

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

What is the enthalpy of reaction?

A

The heat absorbed or released during a chemical reaction at constant pressure.

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

What is the principle of calorimetry?

A

Heat absorbed by the system equals the heat released by the surroundings.

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

What is the third law of thermodynamics?

A

The entropy of a perfect crystal at absolute zero is zero.

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

What is the difference between heat and temperature?

A

Heat is the total energy, while temperature measures the average kinetic energy.

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

What is the standard state of a substance?

A

The form of the substance at 1 bar of pressure and 298 K.

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

What is the relationship between enthalpy and internal energy?

A

ΔH = ΔU + PΔV, where ΔU is internal energy and PΔV is the work done by the system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the bond enthalpy of a molecule?
The energy required to break one mole of bonds in gaseous molecules.
26
How is bond enthalpy used in thermochemical equations?
Used to calculate the enthalpy change in reactions involving bond-breaking and bond-making.
27
What is the relation between enthalpy and temperature?
ΔH = mcΔT, where m is mass, c is specific heat, and ΔT is the temperature change.
28
What is an exothermic reaction?
A reaction that releases heat to the surroundings.
29
What is an endothermic reaction?
A reaction that absorbs heat from the surroundings.
30
What is a reversible process?
A process that can return to its original state after undergoing a change.
31
What is an irreversible process?
A process that cannot return to its original state once changed.
32
What is the formula for calculating work done in a reversible isothermal process?
W = -nRT ln(Vf/Vi), where n is the number of moles, R is the gas constant, and Vi and Vf are the initial and final volumes.
33
What does the law of Hess's state?
The enthalpy change of a reaction is the sum of the enthalpy changes of the steps into which the reaction can be divided.
34
What is the standard enthalpy of formation?
The enthalpy change when one mole of a compound is formed from its elements in their standard states.
35
What is the standard enthalpy of combustion?
The heat released when one mole of a substance reacts with excess oxygen.
36
What is heat of neutralization?
The heat released when an acid and a base neutralize each other to form water.
37
What is heat of atomization?
The enthalpy change when one mole of atoms is formed from the element in its standard state.
38
What is the enthalpy change for the reaction: 2H2 + O2 → 2H2O?
-571.6 kJ/mol (Standard enthalpy of formation of water).
39
What is the formula for calculating the heat released in a reaction?
q = mcΔT, where m is the mass, c is the specific heat, and ΔT is the temperature change.
40
What is the relationship between heat and work in the first law of thermodynamics?
ΔU = q + W, where ΔU is the change in internal energy, q is heat, and W is work.
41
What is the enthalpy of a chemical reaction?
The total heat change at constant pressure during the reaction.
42
What is a spontaneous process?
A process that occurs without the input of external energy.
43
What is the change in entropy for a spontaneous process?
Entropy increases during a spontaneous process.
44
What is Gibbs free energy?
A measure of the spontaneity of a process, calculated as ΔG = ΔH - TΔS.
45
What does a negative Gibbs free energy (ΔG < 0) indicate?
The process is spontaneous.
46
What does a positive Gibbs free energy (ΔG > 0) indicate?
The process is non-spontaneous.
47
What is the formula for the heat of reaction using bond enthalpies?
ΔH = Σ (Bond enthalpies of reactants) - Σ (Bond enthalpies of products).
48
What is a calorimeter?
A device used to measure the heat change in a chemical reaction.
49
What is the relationship between pressure and volume in an isothermal process?
P1V1 = P2V2 (Boyle’s Law).
50
What is an adiabatic process?
A process where no heat is exchanged with the surroundings.
51
What is the formula for enthalpy change in a chemical reaction?
ΔH = Σ (H of products) - Σ (H of reactants).
52
What is the relationship between enthalpy and temperature for an ideal gas?
ΔH = ΔU + Δ(PV), where ΔU is the internal energy change, and Δ(PV) is the work done.
53
What is the standard enthalpy of formation of oxygen?
Zero, as oxygen is in its standard state (O2 gas).
54
What is the heat of neutralization in terms of enthalpy?
The enthalpy change when one mole of H+ ions reacts with one mole of OH- ions to form water.
55
What is the heat of formation of methane?
-74.8 kJ/mol (standard enthalpy of formation for CH4).
56
What is an isobaric process?
A process that occurs at constant pressure.
57
What is the formula for calculating work in an adiabatic process?
W = nCvdT, where n is the number of moles, Cv is the specific heat at constant volume, and dT is the temperature change.
58
What is the relationship between pressure, volume, and temperature in an ideal gas?
PV = nRT (Ideal gas law).
59
What is the heat of fusion?
The heat required to change 1 gram of a solid at its melting point into liquid without a change in temperature.
60
What is the heat of vaporization?
The heat required to change 1 gram of a liquid at its boiling point into gas without a change in temperature.
61
What is the formula for work in a thermodynamic process?
W = PΔV ## Footnote Where P is pressure and ΔV is the change in volume.
62
What is the heat of vaporization?
The heat required to convert one mole of liquid into gas at its boiling point.
63
What is the formula for calculating the work done by an ideal gas?
W = -PextΔV ## Footnote Where Pext is the external pressure.
64
What is the first law of thermodynamics in terms of heat and work?
ΔU = q + W ## Footnote Where ΔU is change in internal energy, q is heat, and W is work done.
65
What is an isochoric process?
A process that occurs at constant volume.
66
What is the formula for calculating the change in internal energy?
ΔU = q + W ## Footnote Where q is heat and W is work.
67
What is an ideal gas?
A gas that follows the ideal gas law, PV = nRT, exactly.
68
What is the difference between internal energy and enthalpy?
Internal energy is the total energy within the system, while enthalpy includes internal energy and the product of pressure and volume.
69
What is a spontaneous reaction?
A reaction that occurs naturally without external intervention.
70
What is the equation for Gibbs free energy?
ΔG = ΔH - TΔS ## Footnote Where ΔG is Gibbs free energy, ΔH is enthalpy, and ΔS is entropy.
71
What is bond dissociation energy?
The energy required to break one mole of bonds in a molecule.
72
What is a state function?
A property that depends only on the state of the system and not on the path taken.
73
What is the law of conservation of energy?
Energy cannot be created or destroyed, only converted from one form to another.
74
What is the heat of fusion?
The heat required to change 1 gram of solid into liquid at its melting point.
75
What is a thermodynamic cycle?
A series of processes that return a system to its original state.
76
What is the enthalpy of formation of a compound?
The heat change when one mole of a compound is formed from its elements in their standard states.
77
What is the heat of combustion?
The heat released when one mole of a substance reacts completely with oxygen.
78
What is the relationship between enthalpy and heat?
Enthalpy is the heat content at constant pressure.
79
What is an adiabatic process?
A process in which no heat is exchanged with the surroundings.
80
What is the formula for the change in enthalpy for a reaction?
ΔH = Σ (H products) - Σ (H reactants).
81
What is the standard enthalpy of formation?
The enthalpy change when one mole of a compound is formed from its elements in their standard states.

Chem (6 decks)

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