Physical Chemistry (Group 2)

Front 1

A ______ is a form of matter that is uniform throughout in chemical composition and physical state.

Back 1

phase

Front 2

A ________ is the spontaneous conversion of one phase into another and may be studied by techniques that include thermal analysis.

Back 2

phase transition

Front 3

The thermodynamic analysis of phases is based on the fact that, at equilibrium, the ______ of a substance is the same throughout a sample.

Back 3

chemical potential

Front 4

The _____ relates the number of variables that may be changed while the phases of a system remain in mutual equilibrium

Back 4

phase rule

Front 5

What is the equation form of the phase rule?

Back 5

F = C -P + 2

Front 6

A _________ is a chemically independent constituent of a system

Back 6

component (C)
F = C - P + 2

Front 7

A solution of sodium chloride has how many constituents? How many components?

Back 7

three constituents: water, sodium ions, and chloride ions

two components: water, and NaCl. Since the quantity of Na and Cl ions are dependent on the quantity of the other, they count as one component

Front 8

In terms of phase behavior, Carbon dioxide's attributes are best explained by _____

Back 8

weak intermolecular forces

Front 9

In terms of phase behavior, water's attributes are best explained by ____

Back 9

extensive hydrogen bonding

Front 10

In terms of phase behavior, Helium's attributes are best explained by ______

Back 10

low mass and weak molecular interactions

Front 11

The _____ of a substance decreases with increasing temperature at a rate determined by its molar entropy.

Back 11

chemical potential

Front 12

The chemical potential of a substance increases with increasing _____ at a rate determined by its molar volume

Back 12

pressure

Front 13

When pressure is applied to a ______, it's vapour pressure rises

Back 13

condensed phase

Front 14

At very low temperatures and provided the pressure is not too low, the _____ phase of a substance has the lowest chemical potential and is therefore the most stable phase

Back 14

solid

Front 15

The __________ equation is an expression for the slope of a phase boundary.

Back 15

Clapeyron

Front 16

The __________ is an expression for the slope of a phase boundary.

Back 16

Clapeyron equation

Front 17

The Clapeyron equation gives an expression for the slope of the solid-liquid phase boundary in terms of the ________

Back 17

enthalpy of fusion

Front 18

The Clausius-Clapeyron equation is an approximation that relates the slope of the __________ to the enthalpy of vaporization.

Back 18

liquid-vapor boundary

Front 19

The Clausius-Clapeyron equation is an approximation that relates the slope of the liquid-vapor boundary to the __________.

Back 19

enthalpy of vaporization.

Front 20

The slope of the ________ is similarly related to the enthalpy of sublimation.

Back 20

solid-vapor boundary

Front 21

In a simple mixture, µ is uniform at __________

Back 21

equilibrium

Front 22

What is Raoult's law?

Back 22

For ideal solutions, pressure of the solution equals pressure of pure component times the mole fraction of the component.

Front 23

dG = __dp ___ dT

Back 23

dG = Vdp - SdT

Front 24

___ = Vdp - SdT + µ_a dn_a + µ_b dn_b

Back 24

dG

Front 25

What is the mole fraction of benzene in a mixture of 0.20 moles benzene and 1.80 moles toluene?

Back 25

(.2/2.0) = 0.1

Front 26

Is partial pressure in vapor phase determined by the number of moles present in liquid solution?

Back 26

Yes.

Front 27

A liquid mixture is referred to as a(n) _________ when Raoult's Law is obeyed by every component.

Back 27

Ideal solution

Front 28

True or false: In a mixture, the mole fraction of the vapor phase (Xi) can be different from the mole fraction of the liquid phase.

Back 28

True.

Front 29

True or false: Ideal solutions are characterized by similar sizes of constituents, and similar intermolecular interactions

Back 29

True

Front 30

True or false: Ideal solutions are characterized by similar intermolecular interactions and similar functional groups.

Back 30

False: Ideal solutions are characterized by similar sizes of constituents, and similar intermolecular interactions

Front 31

What is Raoult's Law?

Back 31

partial pressure (p_A) = pure pressure (p_A^* )
* mole fraction(\chi_A)

Front 32

At 25°C, the density of a 50% (mass) ethanol/water solution is 0.914g per cubic cm. Given that the partial molar volume of water in the solution is 17.4 cubic cm per mol, what is the partial molar volume of the ethanol?

Back 32

56.4 cubic cm per mol

Front 33

The Gibbs energy of mixing is calculated by forming the difference of the Gibbs energies before and after mixing: the quantity is ______ for perfect gases at the same pressure.

Back 33

negative

Front 34

The Gibbs energy of mixing is calculated by forming the difference of the Gibbs energies before and after mixing: the quantity is negative for perfect gases at the same ________.

Back 34

pressure

Front 35

The entropy of mixing of perfect gases initially at the same pressure is _______ and the enthalpy of mixing is zero.

Back 35

positive

Front 36

The entropy of mixing of perfect gases initially at the same pressure is positive and the enthalpy of mixing is _______.

Back 36

zero

Front 37

Suppose that 2.0 mol H2 at 2.0 atm and 25°C and 4.0 mol N2 at 3.0 atm and 25°C are mixed at constant volume. Calculate Δ_mix G. What would be the value of Δ_mix G had the pressures been identical initially?

Back 37

-9.7 kJ, -9.5 kJ

Front 38

Raoult's law provides a relation between the ______ of a substance and its _______ in a mixture

Back 38

1) vapor pressure 2) mole fraction

Front 39

_______ is the basis of the definition of an ideal solution.

Back 39

Raoult's law

Front 40

Henry's law provides a relation between the vapor pressure of a ______ and its mole fraction in a mixture.

Back 40

solute

Front 41

_______ is the basis of the definition of an ideal-dilute solution.

Back 41

Henry's law

Front 42

Henry's law provides a relation between the vapor pressure of a ______ and its _________ in a mixture.

Back 42

1) solute 2) mole fraction

Front 43

The Gibbs energy of mixing of two liquids to form an ideal solution is calculated in the same way as for two perfect gases. The enthalpy of mixing is _______ and the Gibbs energy is due entirely to the entropy of mixing.

Back 43

zero

Front 44

The Gibbs energy of mixing of two liquids to form an ideal solution is calculated in the same way as for two perfect gases. The enthalpy of mixing is zero and the Gibbs energy is due entirely to the _______

Back 44

entropy of mixing.

Front 45

A regular solution is one in which the entropy of mixing is the same as for an ideal solution but the enthalpy of mixing is ______

Back 45

non-zero

Front 46

A regular solution is one in which the ____________ is the same as for an ideal solution but the enthalpy of mixing is non-zero

Back 46

entropy of mixing

Front 47

A(n) _______ is a solution in which the entropy of mixing is the same as for an ideal solution but the enthalpy of mixing is non-zero

Back 47

regular solution

Front 48

In the vapor phase of benzene, if the benzene vapor is treated as ideal gas, then (∂µ/∂p)_T = __?__

Back 48

V_m

Front 49

The reaction Gibbs energy, Δ_rG, is defined as the slope of the graph of the Gibbs
energy plotted against the _______:

Back 49

extent of reaction

Front 50

How does one calculate the equilibrium constant (K)?

Back 50

RT ln K = -Δ_rG^bar

Front 51

The ratio P_b/P_a is known as the reaction quotient, and is symbolized by ____

Back 51

Q

Front 52

_________ is a quantity indicating the overall extent of RXN

Back 52

extent of reaction (ξ)(xi)

Front 53

What is the ratio of (dG)/(dξ)?

Back 53

slope of graph of G vs ξ

Front 54

efficiency of an engine = __?___

Back 54

[work performed(w)] / [heat absorbed from hot source(q_h)]

Front 55

What are 4 processes in Carnot cycles?

Back 55

1) Reversible isothermal expansion 2) Reversible adiabatic expansion (no energy leaves the system as heat, so ∆S = 0) 3) Reversible isothermal compression (energy is released as heat to the cold sink; the change in entropy is q/T) 4) Reversible adiabatic compression (no energy enters the system as heat, so ∆S=0)

Front 56

What is the entropy change for an irreversible adiabatic expansion for an ideal gas?

Back 56

since "irreversible" suggests a spontaneous process, we can assume that ∆S is greater than zero