7.2 States and State Functions

Question 1

State functions

Answer 1

A property of a system that depends only on the current state of that system (independent of the path followed to reach that state)

Question 2

process functions

Answer 2

quantitatively describe the pathway taken from one equilibrium state to another

Question 3

examples of process functions

Answer 3

work (W)

heat (Q)

Question 4

examples of state functions (8)

Answer 4

pressure, density, temperature, volume, enthalpy (H), internal energy (U), Gibbs free energy (G), and entropy (S)

Question 5

standard conditions for measuring enthalpy, entropy and Gibb’s free energy of a reaction

Answer 5

temperature: 298K
pressure: 1atm
concentration: 1M

Question 6

Standard state of an element

Answer 6

the most stable form of a substance

whether the element is predominantly a gas, liquid or solid under standard conditions

Question 7

phase diagrams

Answer 7

graphs that show the standard and nonstandard states of matter for a given substance in an isolated system, as determined by temperatures and pressures

Question 8

Vaporization (evaporation)

Answer 8

LIQUID TO GAS

when an element or compound transitions from its liquid state to its gaseous state

Question 9

Boiling

Answer 9

a specific type of vaporization; the rapid bubbling of the entire liquid with the rapid release of the liquid as gas particles

Question 10

Condensation

Answer 10

GAS TO LIQUID

the change in the state of matter from the gas phase to the liquid phase; it is the reverse of vaporization

Question 11

Fusion (melting)

Answer 11

solid to liquid

Question 12

freezing (crystallization or solidification)

Answer 12

the transition from liquid to solid

Question 13

Sublimation

Answer 13

the direct transition from solid to gas phase

Question 14

Deposition

Answer 14

the direct transition from gas to solid phase

Question 15

lines of equilibrium (phase boundaries)

Answer 15

indicate the temperature and pressure values for the equilibria between phases

Question 16

triple point on phase diagram

Answer 16

the temperature and pressure at which the three phases exist in equilibrium; the point at which all 3 phase boundaries meet

Question 17

Critical point

Answer 17

the temperature at which the liquid and gas phases are indistinguishable

The point where the phase boundary between the liquid and gas phases terminates

Question 18

Supercritical fluids

Answer 18

any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist