Chemistry - Ch 19

Question 1

Spontaneous process

Answer 1

one that proceeds on its own without any outside assistance

Question 2

Reversible process

Answer 2

a system is changed in such a way that the system and surroundings can be restored to their original state by exactly reversing the change

Question 3

Irreversible process

Answer 3

one that cannot simply be reversed to restore the system and its surroundings to their original states

Question 4

Isothermal

Answer 4

one that occurs at constant temperature

Question 5

Entropy

Answer 5

a thermodynamic function associated with the number of different equivalent energy states or spatial arrangements in which a system may be found. It is a thermodynamic state function, which means that once we specify the conditions for a system - that is, the temperature, pressure, etc. - the _____ is defined

Question 6

2nd Law of Thermodynamics

Answer 6

A statement of our experience that there is a direction to the way events occur in nature. When a process occurs spontaneously in one direction, it is non-spontaneous in the reverse direction. It is possible to state this in many different forms, but they all relate back to the same idea about spontaneity. One of the most common statements found in chemical contexts is that in any spontaneous process the entropy of the universe increases

Question 7

Translational motion

Answer 7

an entire molecule can move in one direction (e.g. motions of particles of an ideal gas or a baseball being thrown around a baseball field)

Question 8

Vibrational motion

Answer 8

the atoms in the molecule move periodically toward and away from one another (e.g. tuning fork)

Question 9

Rotational motion

Answer 9

spinning motion (e.g. tops)

Question 10

Microstate

Answer 10

single possible arrangement of the positions and kinetic energies of the gas molecules when the gas is in a specific thermodynamic state

Question 11

3rd Law of Thermodynamics

Answer 11

the entropy of a pure crystalline substance at absolute zero is zero

Question 12

Standard molar entropies

Answer 12

molar entropy values of substances in their standard states

Question 13

Gibbs Free Energy (Free Energy)

Answer 13

a thermodynamic state function that combines enthalpy and entropy, in the form of G = H - TS. For a change occurring at constant temperature and pressure, the change in free energy is Delta G = Delta H - T(Delta S)

Question 14

Standard Free Energies of Formation

Answer 14

this change in free energy associated with the formation of a substance from its elements under standard conditions