CHM 142H Exam 2

rate

The Kc (reaction) is the rate/reverse rate of the reaction.

reverse rate

The Kr (products) is the rate/reverse rate of the reaction.

incorrect

When using the quadratic equation to solve for x in an ICE table problem, you can know which value to use based on if subtracting that value from the original M gives you a negative value. If it is a negative value, that value is correct/incorrect.

Q

To calculate _____, substitute the concentrations or pressures of reactants and products at any given time during a reaction into the equilibrium expression.

products

Nature wants Q = K. If Q < K, nature will make the reaction proceed to the ______.

equilibrium

Nature wants Q = K. If Q = K, the reaction is in ________.

reactants

Nature wants Q = K. If Q > K, nature will make the reaction proceed to the ________.

faster

If K < Q, than the reverse reaction is faster/slower. Products will be lost and reactants will be formed.

5

When the magnitude of K is very small, the solution to an equilibrium problem can be simplified - making it unnecessary to use the quadratic equation. If x is less than ____% of initial concentration.

le chatelier’s principle

If a system at equilibrium is disturbed by a change in temperature, pressure, or a component of concentration, the system will shift its equilibrium position so as to counteract the effect of the disturbance.

used up

If the system is at equilibrium, adding a reaction component will result in some of it being _____.

produced

If the system is at equilibrium, removing a reaction component will result in some of it being _____.

will affect

When gases are involved in equilibrium, a change in pressure or volume will affect/will not affect equilibrium.

more

In gases, higher volume or lower pressure favors the side of the equation with _____ moles of gas.

less

In gases, lower volume or higher pressure favors the side of the equation with _____ moles of gas.

reactant

In endothermic reactions, heat acts like a ______, adding heat drives a reaction toward products.

product

In exothermic reactions, heat acts like a _______, adding heat drives a reaction toward reactants.

products

If a reaction is endothermic, heat being added to it drives the reaction towards _______.

reactants

If a reaction is exothermic, heat being added to it drives the reaction towards _______.

catalysts

_____ increase the rate of both the forward and reverse reactions.

unaltered

If a catalyst is added, equilibrium is achieved faster, but the equilibrium composition remains ______.

lower

If a catalyst is added, the activation energy is lowered, allowing equilibrium to be established at ______ temperatures.

concentration

adding or removing a reactant or product

consume

If a substance is added to a system at equilibrium, the system reacts to ______ some of the substance.

produce

If a substance is removed from a system, the system reacts to ______ more of substance.

pressure

changing the pressure by changing the volume

reduces

At constant temperature, reducing the volume of a gaseous equilibrium mixture causes the system to shift in the direction that ______ the number of moles of gas.

reactant, product

If the temperature of a system at equilibrium is increased, the system reacts as if we added a _____ to an endothermic reaction or a ______ of an exothermic reaction. The equilibrium shifts in the direction that consumes the “excess reagent,” named heat.

acid

Arrhenius. A _____ is a substance that, when dissolved in water, increases the concentration of hydrogen ions (H+).

base

Arrhenius. A ______ is a substance that, when dissolved in water, increases the concentration of hydroxide ions (OH-).

acid

Bronsted-Lowry. A ____ is a proton donor.

base

Bronsted-Lowry. A _____ is a proton acceptor.

donate

A Bronsted-Lowry acid must have at least one removable (acidic) proton (H+) to ______.

accept

A Bronsted-Lowry base must have at least one nonbonding pair of electrons to _____ a proton (H+).

conjugate acid-base pair

Two formulas that differ by H+ are called a ________.

conjugate

Reactions between acids and bases always yield their _______ bases and acids.

inverse

Acid-base and conjugate pairs have ______ relationship in strength. If one is strong, the other is weak.

bases

For strong acids, their conjugate bases do not as as _____ in water.

acids

For strong bases, their conjugate acids do not act as _____ in water.

weak

Generally, conjugate base-pairs in water are weak/strong acids and bases.

weaker

In every acid-base reaction, equilibrium favors transfer of the proton from the stronger acid to the stronger base to form the _______ acid and base.

amphoteric

A species that can behave either as a Bronsted acid or a Bronsted base is called ______.

autoionization of water

Water is one example of a species that is amphoteric. The reaction is known as the ____________.

Kw

The special equilibrium constant _____ is referred to as the ion product constant for water.

neutral

If [H+] = [OH-], the solution is ______.

acidic

If [H+] > [OH-}, the solution is ______.

basic

If [H+] < [OH-}, the solution is ______.

pH

____ is a method of reporting hydrogen ion concentration. In this measurement, only the digits after the decimal point are significant figures in logarithms.

hydronium

A measured pH can be used to determine experimentally the concentration of _______ ion [H3O+] in solution.

pOH

A _____ scale analogous to the pH scale can be defined using the negative base -10 logarithm of the hydroxide ion concentration of a solution [OH-}.

pH meter

One way to measure pH is with a _______, which are used for accurate measurements of pH. Electrodes indicate small changes in voltage to detect pH.

indicators

One way to measure pH is with ______, which give less accurate but quick measurements, and are compounds that have one color in its acidic form and another color in its basic form.

equilibria

The ionization of strong acids and dissociation of strong bases generally are not treated as ________ but rather as a process that go to completion. This makes the determination of pH for a solution of strong acid or strong base relatively simple.

initial concentration

Because the ionization of a strong acid is complete, the concentration of hydronium ion at equilibrium is equal to the ______ of the strong acid.

completely

Strong acids _______ dissociate to ions.

partially

Weak acids ______ dissociate to ions.

acid ionization

Ka is called the __________ constant.

strong, acid

A large Ka value indicates a _____ acid, where a small Ka value indicates a ____ acid.

concentration, equilibrium constant

The degree to which a weak acid ionizes depends on the _______ of the acid and the ____________ for the ionization.

5

It is acceptable to use the “assume small” shortcut if the calculated value of x is less than ____ percent of the initial acid concentration.

dependent

Percent ionization is concentration independent/dependent.

equilibriumThe

pH of # always refers to ______.

incomplete

The ionization of a weak base is _______ and is treated in the same way as the ionization of a weak acid.

stronger, weaker

The larger the Kb, the ______ the base, and the smaller the Kb, the ______ the base.

hydroxide

Solving for x in a typical weak base problem gives us the _______ ion concentration rather than the hydronium ion concentration.

weak, strong

A strong base has a ______ conjugate acid. And a weak base has a _____ conjugate acid.

salt hydrolysis

_________: in which ions produced by the dissociation of a salt react with water to produce either hydroxide ions or hydronium ions — thus impacting pH.

hydroxide

In general, an anion that is the conjugate base of a weak acid reacts with water to produce a _______ ion.

will not

If there is a strong base in the “products”, the forward reaction will/will not occur, and ions can be ignored.

do not

Anions that are conjugate bases of strong acids do/do not hydrolyze to a significant degree. Consequently, a salt composed of the cation of a strong base and the anion of a strong acid, such as NaCl, produces a neutral solution.

acidic

The metal ion in a dissolved salt can react with water to produce a _____ solution.

greatest

The extent of hydrolysis is _______ for the smallest and most highly charged metal ions.

do not

Most metal cations of Group 1 and Group 2 do/do not impact the pH of a solution.

basic

When Kb > Ka, the solution is ______.

acidic

When Kb < Ka, the solution is _____.

neutral

When Kb = Ka, the solution is _____.

ionize

The strength of an acid is measured by its tendency to _______.

acid

Two factors influence the extent to which the _______ undergoes ionization: 1) The strength of the H — X bond, the stronger the bond, the more difficult it is for the HX molecule to break up. 2) The polarity of the H — X bond.

polarized

A molecule is highly ______ if there is a large accumulation of positive and negative charges on the H and X atoms, respectively.

polarized

If the bond is highly ______, HX will tend to break up into H+ and X- ions.

acid

A high degree of polarity gives rise to a stronger _____.

one

Binary acids consist of H and _____ other element.

H —- A

Within a group, _____ bond strength is generally the most important factor.

bond polarity

Within a period, ______ is the most important factor to determine acid strength.

oxoacid

An ______ contains hydrogen, oxygen, and a central, nonmetal atom.

increasing

Within the group of “oxoacids having different central atoms that are from the same group of the periodic table and that have the same oxidation number,” the acid strengthens with _______ electronegativity of the central atom.

increasing

Within the group of “oxoacids having the same central atom but different numbers of oxygen atoms,” acid strength increases with _________ oxidation number of the central atom.

increases

In oxoacids, the ability of chlorine to draw electrons away from the OH group (thus making the O — H bond more polar) ______ with the number of electronegative O atoms attached to Cl.

R

Similar to oxoacids, the strength of carboxylic acids depends on the nature of the ___ group.

stronger

On carboxylic acids, if the R group is more electronegative, the acid will be _____.

donate

A Lewis base is a substance that can ____ a pair of electrons.

accept

A Lewis acid is a substance that can _____ a pair of electrons.

hydrated metal cations

The _______ are primary examples of electron pair donor/acceptor chemistry.

stronger

In hydrated metal cations, higher charges result in stronger water to metal bonds, making them _____ acids.