Quiz review CH 15

coordination complexes

Complex ions are also known as:

2.5x10^-4

Given that the Ksp value for Li3PO4 is 5.9×10−17, if the concentration of Li+ in solution is 6.2×10−5 M, the concentration of PO3−4 must exceed _____ to generate a precipitate.

ksp= 5.62x10^-12

In a saturated solution that is in contact with solid Mg(OH)2, the concentration of Mg2+ is 1.12×10-4 M. What is the solubility product for Mg(OH)2? Mg(OH)2(s)⇌Mg2+(aq)+2OH−(aq) Your answer should include three significant figures. Use the multiplication symbol on your keyboard when entering an answer in scientific notation.

all ions remain solvated

In a solution of magnesium ions and sulfate ions, if the reaction quotient is less than the solubility product:

the type of cation and the type of anion The identities of both the cation and the anion affect Ksp. The expression for Ksp is the product of the concentration of each ion (both cation and anion) raised to the power of the number of that species in the solution.

The Ksp for a substance depends on

[A+][B−]

The Ksp for an ionic salt AB could be equal to:

transition metal cation The central atom in a complex ion is typically a positively charged metal ion, usually from the transition metal block of the periodic table.

The central atom in a complex ion is typically a:

equal to the sum of the charges of the components To find the formal charge on a coordinate complex, one should add the charge of the central atom to the charges on the ligands.

The charge on the complex ion will be:

acid- base equilibria Solubility equilibria

The common ion effect can apply to:

Ag(NH3)2]+ Two ammonia molecules will coordinate with the silver(I) ion to form the complex [Ag(NH3)2]+.

The complex ion that forms when silver chloride dissolves in ammonia has the formula:

the formation of a complex ion

The formation constant (Kf) refers to an equilibrium involving:

[Al(OH)4]- The aluminum ion will coordinate with four hydroxide ions to form the [Al(OH)4]− complex ion. Aluminum has 3 valence electrons to which 3 hydroxide ions attach. The additional electron is the fourth electron where the last hydroxide ion combines.

The formula of complex ion formed when aluminum hydroxide dissolves in sodium hydroxide will be:

5.5x10^-11

What is Ksp for the following equilibrium if MgF2 has a molar solubility of 2.4×10−4 M? MgF2(s)↽−−⇀Mg2+(aq)+2F−(aq) Your answer should have two significant figures.

Ksp= 5.47x10^-6

What is the Ksp for the following equilibrium if calcium hydroxide has a molar solubility of 0.0111 M? Ca(OH)2(s)↽−−⇀Ca2+(aq)+2OH−(aq)

Kf=1/Kd

What is the mathematical relationship between Kf and Kd?

all of the equilibria involved in the system If one equilibrium shifts, this shift will affect all of the other interconnected equilibria as well.

When a system is participating in multiple equilibria, the addition of one component of one of those equilibria will affect:

the dissolved ions and the remaining solid will be in dynamic equilibrium. There will be a dynamic equilibrium between the solid and solvated ions: parts of the solid dissolve at the same rate that its constituent ions recombine and precipitate as more solid.

When an ionic solid is placed in a solvent:

More Ag+ resulting from the dissolution of AgCl will be present in solution at any given time, because Ksp, AgBr<Ksp, AgCl. The Ksp of AgCl is greater than the Ksp of AgBr, which means more silver ions will be present at any time in the solution of AgCl than in the solution of AgBr. Note that this is true regardless of the ligand used to form the complex with Ag+ ([S2O3]2− or NH3).

When comparing the dissolution of AgBr by Na2S2O3 to the dissolution of AgCl by NH3, given the Ksp values for AgBr(5.0×10−13) and AgCl(1.8×10−10), which of the following is true?

decrease the amount of the common ion in the system

When the common ion effect is in action, the equilibrium of a system will shift to:

adding ammonia to aqueous copper hydroxide Ammonia will react with water molecules to generate more hydroxide and thus drive the equilibrium left, generating more precipitate.

Which is an example of an action that generates a multi-equilibrium system?

H2O CH4 OH− A complex ion contains a central ion or atom, often a transition or inner metal, surrounded by at least two other molecules or ions. It must also have an overall charge. All of the other species listed do not meet these criteria.

Which of the following are not complex ions? (Select all that apply)

Ligands often act as Lewis bases. A complex ion has a central atom or ion surrounded by a number of other molecules or ions called ligands. Within a complex ion, the central atom or ion often acts as a Lewis acid and ligands often act as Lewis bases; ligands donate a lone pair of electrons to the central atom or ion to form a coordinate covalent bond. There are a number of different metals that can form complex ions, including most transition metals, post-transition metals, and even alkaline earth metals.

Which of the following statements about complex ions is true?

Ca(OH)2 Calcium makes ionic bonds to the hydroxide ions in Ca(OH)2, so this substance will be a proton acceptor and therefore a base.

Which substance is a base? CH3OH CH3COOH Ca(OH)2 none of the above

the oxidation number on the central atom increases

For oxyacids, acidity increases as:

a Lewis base and a metal ion a proton and a hydroxide ion a displacement reaction

A Lewis acid-base reaction can involve:

Ksp = 4.8×10−9​ The formula for calcium carbonate is CaCO3.The concentration of the calcium ion will be equal to the carbonate concentration because they are released in a 1:1 ratio, so Ksp=(6.9×10−5)2=4.8×10−9

Calculate the Ksp of calcium carbonate, given the molar solubility is 6.9×10−5 molL. Your answer should have two significant figures.

A The compound that is least soluble (with the smallest value of Ksp) will precipitate first.

Compounds A, B, and C are slightly soluble ionic compounds with Ksp values increasing from A to C. If all three of these are present in solution, which compound would selectively precipitate first?

There is not enough information to predict. We cannot predict the acidity or basicity of a compound merely by knowing that it contains a hydroxyl group; more information about its precise structure is needed.

Compounds containing one or more hydroxyl groups are:

amphoteric These criteria includes elements near the diagonal line separating metals and nonmetals, so they can act as either acids or bases depending on their environment.

Compounds where a metalloid with a relatively high oxidation number bears a hydroxyl group are usually:

encourage, slightly soluble

Fill in the blanks to make a true statement. The common ion effect can be most effectively used to _________ precipitation of a _________ ionic solid.

hydroxide ions with fluoride ions Fluoride toothpaste replaces the hydroxide ion in hydroxylapatite (Ca5(PO4)3OH) with a fluoride ion, making it less soluble and therefore more resistant to degradation.

Fluoride toothpaste functions by replacing:

bond strength decreases As the strength of the bond between H and A in HA decreases, the proton is more easily lost (indicating a stronger acid).

For a binary acid HA, acid strength increases as:

Q=Kf

For a system involving a complex ion that is at equilibrium:

down and right Acidity of a compound increases as the location of the parent atom moves down and to the right on the periodic table.

For an acid, when considering the location on the periodic table of the atom that loses the proton, acidity increases: down and left down and right up and left up and right

HCl The acid will react with hydroxide in solution to form water molecules, thus reducing the hydroxide concentration and driving the equilibrium to the right, dissolving more of the solid.

For the following equilibrium, Mn(OH)2(s)↽−−⇀Mn2+(aq)+2OH−(aq) which of the following could be added to promote more dissolution of Mn(OH)2?

KI The addition of MnCl2 adds a common ion, while the addition of acid (i.e. H2SO4) or base (i.e. KOH) changes the pH of the system and thus the amount of dissolved OH−. Thus, the only species that does not affect the system is KI.

For the following equilibrium, Mn(OH)2(s)↽−−⇀Mn2+(aq)+2OH−(aq) which of the following, when added to the system will have no effect on the system?

2.0x10^-3

For the following equilibrium, PbF2(s)↽−−⇀Pb2+(aq)+2F−(aq) If Ksp=3.3×10−8, what is the molar solubility of PbF2? Report your answer in scientific notation with the correct number of significant figures.

[Ca2+] increases, [SO2−4] decreases, mass of solid increases

For the following equilibrium, if CaCl2 is added, how will the quantities of each component change? CaSO4(s)↽−−⇀Ca2+(aq)+SO2−4(aq)

ions will dissolve until Q=Ksp When the solid is placed in pure water, Q will be less than Ksp, as no ions are initially present in the solution. As dissolution occurs, Q will climb until it equals Ksp, at which point dynamic equilibrium will be reached.

If a soluble ionic solid is placed in water, what will happen?

an acid-base reaction with a precipitation reaction

Introducing ammonia into an aqueous solution of magnesium hydroxide generates multiple equilibria because it combines:

Le Chatelier's principle The effect of adding one of the constituent ions of a species that is in equilibrium with its ions in solution—the common ion effect—is a shift in the equilibrium toward the reactant (the undissociated species). This is an application of Le Chatlier's principle.

The common ion effect is an application of:

two substances that share one ion in common The common ion effect involves two ionic solids that have one ion in common, either a cation or an anion.

The common ion effect is named as such because it refers to

precipitation The common ion effect involves the addition of an ion that will shift a solubility equilibrium to generate more precipitate.

The common ion effect is used to generate:

coordinate covalent bonds The bonds holding the ligands in a complex ion to the central atom or ion are known as coordinate covalent bonds.

What types of bonds form between the ligands and central atom of a complex ion?

H2CO3 HCO−3 CO2−3

When carbon dioxide dissolves in the water, several equilibrium reactions are initiated involving:

will change for the second reaction will change for the first reaction will change for the third reaction

When looking at a system comprised of three successive equilibria, if a product of the second equilibrium reaction changes in concentration, the equilibrium concentrations:

Mg3​(PO4​)2​​ Magnesium phosphate is the least soluble of the three (as indicated by the fact that it has the lowest Ksp value), so it would precipitate before the other two salts.

Which of the following substances: Mg3(PO4)2 (Ksp=1.0×10−25), MgF2 (Ksp=3.7×10−8) or MgNH4PO4 (Ksp=2.5×10−13) would precipitate first during selective precipitation?

transition metals Transition metal cations will often act as Lewis acids. The other groups listed are much less likely to form coordinate covalent bonds with Lewis bases, thus these are not good Lewis acids.

Which of the following types of elements are the best Lewis acids?

+1

A complex ion is formed when a central atom with a charge of +1 bonds with two neutral molecules. What is the charge of the complex ion?

encourages precipitation of Mg(OH)2 Ammonia will react with water molecules to generate more hydroxide ions. Hydroxide ions are in equilibrium with insoluble magnesium hydroxide, so by the common ion effect, the solubility equilibrium of Mg(OH)2 will shift to the left, generating more solid.

Adding ammonia to an aqueous solution of magnesium hydroxide:

2 As long as the Ksp values of the relevant salts differ by two orders of magnitude or more, the selective precipitation of these salts will be sequential, with very little overlap.

During selective precipitation, to precipitate all of the least soluble compound before other compounds begin to precipitate, their Ksp values must differ by _______ order(s) of magnitude:

two orders of magnitude

In order for selective precipitation to occur, the Ksp values for potential precipitates must differ by at least:

concentration The common ion effect occurs due to a change in concentration, which disturbs the equilibrium of the system, forcing it to shift to counteract the change.

Le Châtelier's principle explains the common ion effect through a change in:

hydronium ions react with carbonate ions Marble and limestone contain calcium carbonate, so when the hydronium from acid rain comes into contact with these substances, it protonates the carbonate ions, resulting in water-soluble Ca(HCO3)2.

Marble and limestone dissolve in acid rain because:

[HgS2]2− Two sulfide ions will coordinate with the mercury(II) ion to form the complex [HgS2]2−.

Mercury(II) and sulfide form a 1:2 ratio complex that bears the same overall charge of the anion. The empirical formula of this compound is identical to its molecular formula. The formula of this complex is:

Hg2+ can form a complex with sulfide ions Mercury ions form complex ions with sulfide ions, allowing HgS to dissolve in an excess of sulfide.

Mercury(II) sulfide is insoluble in pure water, but is soluble in a solution of sodium sulfide because:

mol/L

Molar solubility is expressed in units of:

the product of one equilibrium participates in a separate equilibrium If a compound generated from one equilibrium reaction participates a different equilibrium reaction, we need to describe the system using multiple equilibrium expressions.

Multiple equilibria are required to describe a system when:

the solubility of the ionic solid decreases Increasing the concentration of the common ion causes the solubility of the corresponding ionic solid to decrease, resulting in additional precipitate.

Once the concentration of the common ion is increased:

H3PO4(aq)+H3O+(aq)↽−−⇀H4PO4(aq)+H2O(l) Phosphoric acid is a triprotic acid. When it is fully deprotonated as the phosphate ion (PO3−4), it cannot accept any more than three protons. H4PO4 does not exist.

Phosphate ions can participate in multiple equilibria when in acidic solution. Which of the following is NOT one of them?

two anions form slightly soluble compounds with the same cation two cations form slightly soluble compounds with the same anion When two different ions could each potentially form a precipitate with the same counterion, the compound with the lower solubility will selectively precipitate out of the solution.

Selective precipitation occurs when:

he Kf of [Ag(NH3)2]+ is so large Because the Kf of the complex ion is very large, all of the silver ions that dissociate from AgCl will form the complex ion with ammonia. The silver ion concentration now being depleted, solid AgCl will continue to dissolve bit by bit, releasing increasing amounts of Ag+ for complexation with ammonia until all of the AgCl eventually dissolves.

Silver chloride is soluble in ammonia because:

acidity of the ocean Carbon dioxide reacts with water molecules to produce carbonic acid, which then ionizes, increasing the hydronium concentration and harming the ecosystem.

The increased dissolution of carbon dioxide in ocean water is problematic because this increases the:

ligands

The ions or molecules that surround the central atom in a complex ion are called:

the stoichiometry of the complex ion In the expression for Kf, the concentrations of the ions that comprise the complex ion will be raised to the power of their stoichiometric coefficients. Thus a change in these concentrations this will have a dramatic mathematical effect on the magnitude of Kf.

The magnitude of Kf will be significantly influenced by:

related to its Ksp value The molar solubility of a salt is always directly related to its Ksp value. Typically, a salt's molar solubility will be greater in magnitude than its Ksp, but this is not always the case.

The molar solubility of a substance is: always less than its Ksp value independent of its Ksp value equal to its Ksp value related to its Ksp value

A coordinate covalent bond is a bond in which one atom supplies both of the shared electrons in the bond. A coordinate covalent bond is defined as a bond in which one atom supplies both of the shared electrons in the bond.

The term coordinate covalent bond best fits which of the following descriptions?

Lewis bases

Typically, the ligands in a complex ion are:

Under the Lewis model of acids and bases, an acid is defined as an electron pair acceptor.

Under the Lewis model, an acid is a(n):

H2SO4 Sulfur makes covalent bonds to the oxygen atoms in sulfuric acid, so this substance will be a proton donor and therefore an acid.

Which substance is an acid? H2O Al(OH)3 SO2−4 H2SO4

NaCl The formation constant for [HgCl4]2− is quite large. Thus, if more chloride ions are added to the solution via a soluble chloride salt (like NaCl), this will allow the soluble complex ion to form, thereby dissolving all of the HgCl2 eventually.

You are trying to completely dissolve a sample HgCl2 in water. Which of the following should you add to the mixture to accomplish this? AgCl NaCl more HgCl2 Hg2+

some CuNO3 The Kf of the complex ion [Cu(CN)2]− is large and adding more Cu+ ions to the mixture will reduce the amount of remaining free CN− ions.

You have a mixture of solid CuCN in water. You know that a small amount of CuCN will dissolve to produce cyanide ions in the water. What can you add to ensure that the solution contains no free cyanide? more solid CuCN more H2O some AgCN some CuNO3

0.0027

given that the Ksp value for Ca3(PO4)2 is 8.6×10−19, if the concentration of Ca2+ in solution is 4.9×10−5 M, the concentration of PO3−4 must exceed _____ to generate a precipitate. Report your answer with two significant figures. When reporting your answer in scientific notation, use the multiplication symbol, ×, not the letter x.

aluminum forms a complex ion with excess hydroxide Aluminum hydroxide will dissolve in a solution of sodium hydroxide, because the excess hydroxide will allow the [Al(OH)4]− ion to form, a complex ion that is soluble in water.

Aluminum hydroxide is insoluble in pure water but dissolves in a solution of sodium hydroxide because:

sodium hydroxide Al3+ will form a coordinate complex with four OH− ions. The ionic compound aluminum hydroxide has the formula Al(OH)3; this compound is insoluble in water, but in the presence of excess OH− ions, it will ultimately dissolve as the complex ion [Al(OH)4]−. Interestingly, this phenomenon is exactly the opposite of the common ion effect.

Aluminum hydroxide is insoluble in pure water, but it will be soluble in a solution of:

The complex ion is favored over solid silver chloride. The free Ag+ ion is unstable.

Aqueous ammonia is added to a mixture of silver chloride and water. Given that Kf for the reaction between Ag+ and NH3 is large, which of the following are true? (Select all that apply)

the atom bound to the hydroxyl group has a very low electronegativity If the atom directly bound to the hydroxyl group has a low electronegativity, the bond will be highly polarized toward the hydroxyl oxygen. Consequently, the hydroxyl group may cleave, resulting in hydroxide ions in solution and indicating basic behavior.

Compounds with hydroxyl groups are more likely to act as a base if:

bonds to the central atom are covalent If the central atom can form covalent bonds to the hydroxyl groups, these bonds will be difficult to cleave, and the O−H bond will be more likely broken in an acid-base reaction. This would make the compound a proton donor and therefore an acid.

Compounds with hydroxyl groups are more likely to act as an acid if:

the bond(s) connecting the hydroxyl group(s) to the central atom is/are ionic If the central atom can form covalent bonds to the hydroxyl groups, these bonds will be difficult to cleave. This deceases the basicity of such compounds relative to ionic hydroxides like NaOH.

Compounds with hydroxyl groups are more likely to act as bases if:

SO3 in O2−+SO3→SO2−4

Consider the reactions below. Which of the following correctly identifies the Lewis acid? SO3 in O2−+SO3→SO2−4 O2− in O2−+SO3→SO2−4 F− in F−+BF3→BF−4 BF−4 in F−+BF3→BF−4

the resulting acid-base reactions generate hydronium that is harmful to coral When carbon dioxide dissolves in water, the carbonic acid produced releases hydronium ions. These will readily protonate all of the of carbonate ions released by the minimal dissolution of the calcium carbonate skeletons of coral, as carbonate is a strong base. However, once these carbonate ions are protonated as HCO−3, the calcium carbonate skeletons will continue to dissolve to remain in equilibrium with their constituent ions. If this continues indefinitely, the entire skeleton of the coral will dissolve.

Coral reefs are impacted by the multiple equilibria that occur in ocean water through dissolution of carbon dioxide in the sense that:

[Al3+] increases, [PO3−4] decreases, mass of solid decreases If acid is introduced, protons will be transferred to the relatively basic phosphate ions, so the phosphate ion concentration will decrease. This then causes the equilibrium to shift right, dissolving solid and generating more aluminum ions.

For the following equilibrium, if HCl is added, how will the quantities of each component change? AlPO4(s)↽−−⇀Al3+(aq)+PO3−4(aq)

ksp= 6.3x10^-10

For the following equilibrium, if the concentration of A2+ is 5.4×10−4 M, what is the solubility product for the generic salt AB2? AB2(s)↽−−⇀A2+(aq)+2B−(aq) Report your answer in scientific notation. Your answer should have two significant figures.

ksp=2.5x10^-25

For the following equilibrium, if the concentration of B− is 9.3×10−7 M, what is the solubility product for AB3? AB3(s)↽−−⇀A3+(aq)+3B−(aq) Your answer should have two significant figures.

1/3x Each equivalent of dissolved Ca3(PO4)2 releases 3 Ca2+ ions, so the concentration of the calcium ion will be three times the molar solubility of Ca3(PO4)2.

For the following equilibrium, if the concentration of calcium ion is X, what will be the molar solubility of calcium phosphate: Ca3(PO4)2(s)↽−−⇀3Ca2+(aq)+2PO3−4(aq) Report your answer as a fraction in terms of X.

X

For the following equilibrium, if the concentration of the sulfate ion is X, what will be the molar solubility of strontium sulfate? SrSO4(s)↽−−⇀Sr2+(aq)+SO2−4(aq) Report your answer in terms of X.

KCl Potassium chloride would introduce more chloride ions into solution, thus driving the equilibrium left to generate more precipitate.

For the following equilibrium, what substance, when added, would cause the system to shift left? AgCl(s)↽−−⇀Ag+(aq)+Cl−(aq) HNO3 AgI KCl KOH

add more ions to the solution -shift left

How could you manipulate a solution in a lab to form more precipitate?

[Al3+]<[F−] There are six fluoride ions and only one aluminum ion per formula unit, so the concentration of fluoride in solution must be six times the concentration of aluminum.

If [AlF6]3− is dissolved in pure water, what will be true about the system?

[CN−]>[NH3] There are four cyanide ions per formula unit of [Cd(CN)4]2−, while there are two ammonia ions per formula unit of [Ag(NH3)2]+. Since their Kf values are roughly equal, these complexes dissociate to roughly the same (very small) degree, but the dissociation of [Cd(CN)4]2− produces a higher concentration of CN− than the concentration of ammonia produced by the dissociation of [Ag(NH3)2]+. Consequently, the concentration of CN− in solution must be higher than that of ammonia.

If a solution is formed with equimolar amounts of [Cd(CN)4]2− (Kf=1.3×107) and [Ag(NH3)2]+ (Kf=1.7×107), what will be true about the system?

AgBr will dissolve partially Sodium thiosulfate must be present in significant excess of the amount of silver bromide in order to promote the dissolution of all the AgBr present. Note that there are two thiosulfate ions per silver ion in the complex ion; in order for all of the silver content of silver bromide to be bound up in this complex, there must be twice as much thiosulfate as silver in the reaction container. Furthermore, the silver-thiosulfate complex is in equilibrium with its free ions. Therefore, an excess of thiosulfate ion must be added to ensure that the complex is favored in this equilibrium.

If equimolar amounts of sodium thiosulfate and silver bromide are added together, what will happen?

Silver iodide would precipitate first. In this example of selective precipitation, silver iodide would precipitate first. The reason this occurs is that silver iodide is much less soluble in water than the other silver halides.

If silver ions were slowly added to a mixture of aqueous halide ions, which compound would precipitate first? Silver chloride would precipitate first. Silver bromide would precipitate first. Silver iodide would precipitate first. All possible silver halides would precipitate at the same time.

precipitate formation

In order for AgBr to dissolve through complex ion formation, the reaction quotient for AgBr must be less than its Ksp value. If not, AgBr dissolution will be exceeded by:

Kf​ > Ksp​​ If Kf is greater than Ksp, complex formation will be favored over precipitation.

In order for a complex ion to form, what must be true about the formation constant of the ion and the solubility product of the ionic solid? Fill in the blank with < or > or =

the constitutent ions of two ionic solids, with precisely one ion in common

In order for the common ion effect to be applicable, which of the following must be present in solution?

aqueous equilibria ionic solids The common ion effect requires that ions bind to form a precipitate, which is an ionic solid, and this requires that the ions be present in aqueous solution in order to be observed.

In order to observe the common ion effect, what components must be involved? Select all that apply

increase The common ion effect involves the addition of a particular ion, which will in turn cause the system to shift away from the side that contains that ion.

In order to promote the common ion effect, the concentration of the common ion must first:

decrease the molar solubility of the solid relative to its molar solubility in pure water. If the constituent ions of a slightly soluble solid are already in solution, this will decrease the molar solubility of the solid. This is the result of the common ion effect . The system will then shift away from the side containing that ion in order to decrease the amount of the common ion in the system in an attempt to restore balance, thus resulting in the decrease of the molar solubility of the solid.

Placing a slightly soluble ionic solid in a solution containing common ions will

the dissociation of a complex ion By convention, the formation constant Kd refers to an equilibrium in which ligands dissociate from the central atom of a complex ion in solution.

The dissociation constant (Kd) refers to an equilibrium involving:

Lewis is more broad All Bronsted-Lowry acid-base reactions can also be described as Lewis acid-base reactions, but not all Lewis acid-base reactions can be termed Bronsted-Lowry acid base reactions. The Lewis model thus a more comprehensive definition of acids and bases, as it encompasses a broader spectrum of acid-base interactions.

What is true about the two models of acids and bases (the Lewis model and the Bronsted-Lowry model)?

4.7

What mass (in grams) of Na2S2O3 is needed to dissolve 2.5 g of AgBr in a 1.0 L solution if Ksp for AgBr is 3.3×10−13 and Kf for [Ag(S2O3)2]3− is 4.7×1013?

KOH Adding potassium hydroxide increases the hydroxide concentration, which drives the equilibrium to the left, promoting the formation more precipitate. Note that Pb(OH)2 is insoluble, so the introduction of this salt to the solution will not cause any appreciable increase in the concentration of hydroxide.

What should be added to the following equilibrium to generate more precipitate? Cu(OH)2(s)↽−−⇀Cu2+(aq)+2OH−(aq)

Extra calcium ions Extra fluoride ions Adding calcium ions will increase the concentration of Ca2+ in solution, pushing the reaction towards the precipitate. A similar effect will be seen for the fluoride ion.

When looking at the equilibrium between calcium fluoride and its aqueous ions, what could be added to solution to promote precipitation of calcium fluoride? CaF2(s)↽−−⇀Ca2+(aq)+2F−(aq)

magnesium sulfate Calcium carbonate and calcium phosphate are insoluble, so they will not release enough calcium ions to initiate the common ion effect. Magnesium sulfate is soluble and will therefore introduce additional sulfate ions in the system, causing the equilibrium to shift towards the precipitation of calcium sulfate.

When looking at the equilibrium between calcium sulfate and its aqueous ions, what could be added to solution to promote precipitation of calcium sulfate? magnesium sulfate calcium carbonate magnesium sulfite calcium phosphate

Potassium hydroxide

When looking at the equilibrium between lead hydroxide and its aqueous ions, what could be added to solution to promote precipitation of lead hydroxide?

potassium bromide

When looking at the equilibrium between silver bromide and its aqueous ions, what could be added to solution to promote precipitation of silver bromide?

Kf​ > Ksp​​ The formation constant for [Ag(S2O3)2]3− is very large, so complex ion formation is dramatically preferred.

When sodium thiosulfate is added to a solution of silver bromide, all the silver ions in solution will form complex ions because? Fill in the blank with either < or > or =

H2SO2 The sulfate ion will not lose any oxygen atoms by the equilibria involved in the ionization of sulfuric acid in water, so H2SO2 is not formed.

When sulfuric acid is dissolved in water, which of the following species will NOT be present in solution?

3.1×10−29 A smaller equilibrium constant means that reactants (in this case, the solid) are favored at equilibrium, so the smallest Ksp represents the lowest solubility.

Which Ksp value corresponds to the lowest solubility? 1.4×10−12 5.6×10−18 9.2×10−23 3.1×10−29

multiple ionizations of a polyprotic acid an acid-base reaction and a precipitation reaction a precipitation reaction and the formation of a coordinate complex

Which are possible combinations of reactions that qualify as a set of multiple equilibria?

The dissociation constant is the equilibrium constant for the dissociation of a complex ion into its components in solution. The dissociation constant is defined as the equilibrium constant for the dissociation of a complex ion into its components in solution.

Which description best fits the definition of dissociation constant?

The formation constant is the equilibrium constant for the formation of a complex ion from its components in solution.

Which of the following best describes the term formation constant?

HCl HCl is monoprotic; it can only ionize once, and in fact ionizes completely in solution. Therefore this acid does not participate in ANY equilibrium to an appreciable extent.

Which of the following cannot be a component of a multi-equilibrium system? H2CO3 H3PO4 H2SO4 HCl

A molecule of ammonia combines with a proton to form the complex ion known as ammonium. Coordinate covalent bonds result when one of the atoms in a bond provides both bonding electrons. In the last reaction listed, ammonia shares its lone pair of electrons with a proton to form an ammonium complex. In order to qualify as a coordinate covalent bond, the bond formed must be covalent, not ionic.

Which of the following is an example of a Lewis acid-base reaction?

BF3 BF3 is a Lewis acid because the central boron atom is electron-deficient. It does not qualify as a Bronsted-Lowry acid because it has no hydrogens to donate to a Bronsted-Lowry base.

Which of the following is defined as a Lewis acid rather than a Bronsted-Lowry acid?

HCl Out of Si, P, S, and Cl, chlorine is the most electronegative element. Thus Cl can best accommodate the negative charge that will result when its parent acid donates a proton. This makes HCl the strongest acid of the four.

Which of the following is the strongest acid?

HI Hydroiodic acid is the strongest acid of these four. When comparing the acidity of hydrohalic acids (HX, where X is a halogen), acidity increases with the ionic radius of the halogen. As the iodide ion (the conjugate base of HI) is exceptionally large, it accommodates a negative charge well and remains quite stable as I−. Consequently, HI dissociates to the greatest extent of these four and is thus the strongest acid.

Which of the following is the strongest acid? HF HCl HBr HI

H2Te Out of each of these acids, tellurium has the central atom that is lowest on the periodic table. Thus H2Te is the most acidic compound of the four, since tellurium has the largest atomic radius. As you go down the group on the periodic table the acidity increases.

Which of the following is the strongest acid? Yes that's right. Keep it up! H2O H2S H2Se H2Te

PH3 Looking at each of these compounds, we see that H2S and HCl are, in fact, acids. However, PH3 has a structure similar to NH3, making it a weak base.

Which of the following is the strongest base? PH3 HCl H2S none of the above

H2O Basicity of a compound increases when the most basic atom in the compound is higher on the periodic table. The higher the placement of this atom on the periodic table, the smaller its atomic radius, and the better it can accommodate a proton. Oxygen is the highest on the periodic table of the four basic atoms in these compounds, so water is the most basic compound of these four.

Which of the following is the strongest base? H2O H2S H2Se H2Te

The compounds contain a weak base that reacts with acid. The formation of multiple equilibria cause more of the solid to dissolve. The equilibrium position of the dissolution reaction is shifted to replace anions lost through another reaction. Compounds such as calcium carbonate (CaCO3) are susceptible to attack by acids because the anion of the compound can react with acid. For calcium carbonate, CaCO3(s)↽−−⇀Ca2+(aq)+CO32−(aq)CO32−(aq)+H3O+(aq)↽−−⇀HCO3−(aq)+H2O(l)HCO3−(aq)+H3O+(aq)↽−−⇀H2CO3(aq)+H2O(l) These reactions increase the solubility of the solid as the carbonate ion reacts with acid.

Why are compounds that make up coral, teeth, limestone, and marble susceptible to attack by acid? An example of one such compound is calcium carbonate (CaCO3).

NaF The formation constant (Kf) for the formation of the complex ion [AlF6]3− is large. Thus the addition of a soluble fluoride salt, such as NaF, will eventually pull all of the aluminum and fluoride ions into the solution by the formation of this complex.

You attempt to dissolve a large sample of AlF3 in water and find that not all of it dissolves. Which of the following should you add to the mixture to ensure complete dissolution of the sample?