Exam 3

Contains: Ch 13: Fundamental Equilibrium Concepts & Ch 14A: Acid-Base Equilibria

Reversible Reactions

Reversible Reactions

Proceed in both forward and backward direction

Reaction quotient (Q)

The status of a reversable reaction

Formula for the Reaction quotient

Q = Products / Reactants

Equilibrium Constant (K)

The constant value of Q exhibited by a system at equilibrium

When the reaction quotient (Q) is equal to the equilibrium constant (K) the reaction is…

at equilibrium

When the reaction quotient (Q) is greater than the equilibrium constant (K) the reaction is…

The reaction is favoring reactants

When the Reaction quotient (Q) is less than the equilibrium constant (K) the reaction is…

The reaction is favoring products

Equation for Equilibrium Constant

K= Products / Reactants

Homogeneous equilibrium

takes place in in liquid or gaseous solutions

What should not be included in a Q or K expression?

Any liquid or solid reactants or products

Heterogeneous Equilibrium

involves reactants and products in two or more different phases

Changing the direction of a chemical reaction does what to the equilibrium constant?

Reverses it (K → 1/K)

Changing the stoichiometric coefficients in an equation does what to the equilibrium constant?

it would be multiplied by the scale factor of the equation (K → XK)

When there are two or more steps in an equation how can you calculate its equalibrium constant for the whole equation?

Multiply all of the equilibrium constant together.

If you add a reactant/ remove a product from a reaction, will the equation shift right or left?

It will shift right

If you remove a reactant/ add a product to a reaction, will the equation shift right or left?

It will shift left

If you increase the pressure/ decrease the volume to which side will the equation shift?

The side with less moles of gas

In an endothermic reaction decreasing the temperature will cause a shift to which side is the reactant or the product?

To the reactants side

In an exothermic reaction decreasing the temperature will cause a shift to which side is the reactant or the product?

To the products side

When a catalyst is added to the system what will happen to the equilibrium constant?

Nothing

Bronsted-Lowery Acid

Donates a proton to another

Bronsted-Lowery Base

Receives a proton to another

Conjugate base

When an acid donates a proton, the species that remains

Conjugate Acid

When an base recives a proton, the species that remains

Amphoteric substance

Species capable of either donating or accepting protons (ex. H2O)

pH = ?

? = -log[H3O]

pOH = ?

? = -log[OH]

pH + pOH = ?

? = Kw = 14

If pH < 7, then the solution is?

Acidic

If pH = 7, then the solution is?

Neutral

If pH > 7, then the solution is?

Basic

HClO4

Perchloric acid

HCl

Hydrochloric acid

HBr

Hydrobromic acid

HI

Hydroiodic acid

HNO3

Nitric acid

H2SO4

Sulfuric acid

Strong acid

Acids that ionize completely

Weak acid

Acids that do not ionize completely

Acid - ionization Constant

The equilibrium constant for an acid

Percent ionization

The ratio of the equilibrium H3O concentration to the initial HA concentration, multiplied by 100%.

Strong Bases

Bases that completely ionize

LiOH

Lithium Hydroxide (Base)

NaOH

Sodium Hydroxide (Base)

KOH

Potassium Hydroxide (Base)

Ca(OH)2

Calcium Hydroxide (Base)

Sr(OH)2

Strontium Hydroxide (Base)

Ba(OH)2

Barium Hydroxide (Base)

Weak bases

Bases that are not completely

Kw = 1 * 10^-14 = ?

? = Ka * Kb

Leveling Effect

The strength of a strong acid is limited by the basicity of the solvent

Binary Acid

A binary compound where one elements is hydrogen and the other is a nonmetal

Ternary Acid

A compound composed of hydrogen, oxygen, and some third element.