CH 102 Exam #4: Conceptual Information

A Higher Ksp indicates?

Higher Solubility

What is Ksp an indicator of?

The solubility of a compound

What is Molar Solubility (S)?

The # of moles of a solute that will dissolve in 1 Liter of a solution

The addition of a Common Ion causes?

Lower Solubility 

What are the (3) Common Basic Anions?

OH-, CO32-, S2-

Higher pH causes?

Lower Solubility

Lower pH causes?

Higher Solubility

Excess of what compound causes occurrence of precipitate?

NaCl (Salt)

What is a Ligand?

A neutral molecule that acts as a Lewis Base + a Central Metal Cation

Q = Ksp

Saturated Solution & No Precipitate

Q < Ksp

Unsaturated Solution & No Precipitate

Q > Ksp

Supersaturated Solution & Unstable

(Precipitate will eventually form)

What is a Complex Ion?

A Central Metal Cation + Ligand

What is the 1st Law of Theromodynamics?

Total Energy of the Universe is constant

What is the 2nd Law of Thermodynamics?

Entropy of the Universe increases in any Spontaneous Process

What is a Spontaneous Process?

A process that occurs without ongoing outside intervention

True or False: If a process is Spontaneous in one direct it MUST be Nonspontaneous in the opposite direction

True

How is Spontaneity determined?

By comparing Enthalpy & Entropy

True or False: Spontaneity is NOT the same as Speed

True

How does a Catalyst effect Spontaneity?

Catalysts can make Spontaneous Reactions faster, but they cannot make a Nonspontaneous Reaction occur

Enthalpy Change (ΔH) =

H Products - H Reactants

-ΔH indicates?

Exothermic Reaction

+ΔH indicates?

Endothermic Reaction

A reaction is generally ? if the bonds in the products are stronger than the bonds in the reactants

Exothermic

A reaction is generally ? if the bonds in the products are weaker than the bonds in the reactants

Endothermic

ΔH favors?

Exothermic Reactions

What is Enthalpy (H)?

Internal Energy + Pressure Volume Work Energy

What is Entropy (S)

A thermodynamic function that increases with number of energetically equivalent ways (W) to arrange the components of a system to achieve a particular state

The higher (W) is…

The Higher Entropy

What is Boltzmann Constant?

1.38 × 10 -23

What does Macrostate refer to?

The system as a whole

ΔS is favorable when (+): What are changes that increase Entropy?

1) Solids dissociating into ions upon dissolving

2) Reactions with more moles of products than reactants

3) Heat transfer from hotter substance to colder substance

4) Phase transitions: Solid →Liquid →Vapor

Freezing of water at temperatures below 0 °C is an example of a:

Spontaneous Process

ΔSsurr depends on?

Original Temperature

ΔSsurr is inversely proportional to:

Temperature

ΔSsurr is directly proportional to:

Heat Gained/ Lost by Surroundings

ΔG = 0 means?

Reaction is at Equilibrium

-ΔG indicates?

Spontaneous Process

+ΔG indicates?

Nonspontaneous Process

True or False: If ΔH and ΔS have OPPOSITE signs, spontaneity does NOT depend on temperature

True

X° indicates?

Standard State Conditions

(1 M, 25° C, 1 atm)

What is the 3rd Law of Thermodynamics?

Absolute Entropy: For a perfect crystal at absolute 0, the absolute Entropy is 0

*Every substance that is NOT a perfect crystal at absolute 0 has a +S

Larger Molar Mass indicates?

Larger Entropy

Less Constrained Structures indicate?

Larger Entropy

What is Free Energy?

The maximum amount of energy released from a system that is available to do work on the surroundings

ΔG = ΔG° when?

Only when reactants and products are in their standard states

Keq = 1 : ΔG° is 0:

Eeaction is at equilibrium under standard conditions

Keq > 1 : -ΔG° :

Forward reaction is spontaneous under standard conditions

Keq < 1 : +ΔG° :

Reverse reaction is spontaneous under standard conditions

Q > Keq :

+ΔG

Q < Keq :

-ΔG

What is an Oxidation State?

A number assigned to an element that represents the number of electrons that an atom can gain, lose, or share when chemically bonding with an atom of another element

All Free Elements Ex: (Na, Cl2) have an Oxidation State of?

0

Monoatomic Ions Ex: (Na=+1) have an Oxidation State:

Equal to their charge

Fluorine Oxidation State:

-1

Hydrogen Oxidation State:

+1

Oxygen Oxidation State:

-2

The Reducing Agent contains the element that is:

Oxidized

The Oxidation Agent contains the element that is:

Reduced