Chem 2 Chap 17 hw
Match each of the following cations with the anion used to precipitate it selectively in a qualitative analysis procedure. Instructions
- Cl^- - S^2- - OH^- - CO3^2-
Which of the following equlibria correctly represents a saturated aqueous solution of ionic compound, MX, in contact with undissolved MX (s)?
MX (s) ⇌ M+ (aq) + X- (aq)
Match each description concerning the solubility of a metal hydroxide (M(OH)nM(OH)n) in acidic solution to the correct aqueous equilibrium.
- M(OH)n -> M^n+ (aq) + nOH^- (aq) - H3O^+ (aq) + OH^- (aq) -> 2H2O (l) - M(OH)n (s) + nH3O^+ (aq) -> M^n+ (aq) + 2nH2O (l)
The Ksp for Fe(OH)2 is 1.6 x 10-14. Which of the following procedures would increase the solubility of Fe(OH)2? Select all that apply.
Addition of 1.0 M HCl (aq) Addition of 1.0 M NaCN (aq)
Which of the following quantities must be known in order to calculate the pH of an acid-base buffer solution using the Henderson-Hasselbalch equation? Select all that apply.
Concentration of weak acid (or weak base) Concentration of conjugate base (or conjugate acid) Ka of weak acid or Kb of weak base
Complete the following equilibrium concerning the formation of a complex ion. Cr3+ + 4OH- ⇌ ?
Cr(OH)4-
The formation of the complex ion Cu(CN)42- is correctly represented by which of the following equilibrium expressions?
Cu2+ + 4CN- ⇌ Cu(CN)42-
Which of the following equations correctly represents the neutralization of a weak acid (HA) with a strong base (MOH)? Select all that apply.
HA (aq) + MOH (aq) → MA (aq) + H2O (l) HA (aq) + OH- (aq) → A- (aq) + H2O (l)
Which of the following conjugate acid-base pairs is the best choice to prepare a buffer of pH 3.50?
HCOOH/HCOONa (pKa of HCOOH = 3.74) Reason: The pKa of the weak acid component should be as close as possible to the desired pH.
Which of the following options correctly describe how to calculate the pH at various stages during the titration of a strong acid against a strong base? Select all that apply.
Initial pH = -log[HA]. At the equivalence point pH = 7.00.
Which of the following statements correctly describe the solubility product constant Ksp for a slightly soluble substance? Select all that apply.
Ksp is independent of the concentrations of the ions in solution. The value of Ksp indicates how far a dissolution equilibrium proceeds in favor of dissolved solute.
Which of the following will NOT become more soluble if the pH of the solution is decreased? Select all that apply.
PbCl2 AgBr
Consider the dissolution PbSO4 (s) ⇌ Pb2+ (aq) + SO42- (aq). When Na2SO4 is added to the system the presence of the common ion ______ causes the equilibrium to shift to the ______ and the solubility of PbSO4 will ______, in accordance with Le Chatelier's principle.
SO42-, left, decrease
What happens when NaX is added to an aqueous solution of a weak acid HX? Select all that apply. HX (aq) + H2O ⇌ H3O+ (aq) + X- (aq)
The pH of the solution increases. The equilibrium shifts to the left (more reactants).
Which of the following options correctly describe the reaction quotient, Q? Select all that apply.
The reaction quotient is used to predict whether or not precipitation will occur. Q has the same form as Ksp except that the concentrations of ions are not necessarily equilibrium concentrations. The reaction quotient is used for concentrations of ions that may or may not correspond to equilibrium conditions.
55 mL of a 0.25-M solution of the weak acid, HA, is titrated with 0.30 M NaOH. Which of the following statements correctly describes this titration after 60. mL of the NaOH has been added?
The titration is beyond the equivalence point. The solution is basic (pH > 7).
Select the least soluble compound from the following list.
Zn(OH)2 (Ksp = 1.8 x 10-14)
Compared to the titration curve for titration of a strong acid with a strong base, the curve for titration of a weak acid with a strong base has which of the following features? Select all that apply.
a higher initial pH for equal acid concentrations a shorter vertical region near the equivalence point
Match each compound to the substance(s) that would increase the solubility of the compound when present in aqueous solution. Instructions
AgCl: NH3 MgCO3: HCl Al(OH)3: NaOH or HCl
Which of the following statements correctly describes an acid-base indicator? Select all that apply.
An acid-base indicator is selected whose color change coincides with the steepest part of the titration curve. An acid-base indicator is usually a weak organic acid or base for which the ionized and un-ionized forms are different colors. Many acid-base indicators are plant pigments.
Match each stage of a weak acid-strong base titration with the correct description of how to calculate [H3O+] and/or pH. Instructions
initial pH: Calculate [H3O+] using Ka and [HA]initial before equivalence point: [H3O+] =Kax[HA][A-]; [HA] and [A-] determined using reaction table at equivalence point: Calculate [OH-] usingKband [A-]; [H3O+] =Kw[OH-] after equivalence point: pH depends on excess base added
A complex ion consists of a central metal _____ covalently bonded to one or more ions or molecules.
ion
A buffer solution consists of 0.45 M HCOOH and 0.63 M HCOONa (pKa for HCOOH = 3.74). Which option shows the correct calculation for the pH of the buffer after 0.020 mol of solid NaOH is added to 1.0 L of the solution?
pH = 3.74 + log0.65/0.43 Reason: 0.020 mol of NaOH reacts with HCOOH so that [HCOOH] = 0.43 M. [HCOONa] increases correspondingly.
A metal hydroxide is combined with each of the following solutions. List the solutions in order of maximizing the solubility of the metal hydroxide. The solution that dissolves the most metal hydroxide belongs at the top of the list.
- acidic solution - neutral solution - basic solution
List the steps to solve for the molar solubility of an ionic compound in the correct order they should be carried out. The first step belongs at the top of the list.
- construct an equilibrium table under the equilibrium equation for the ionic compound - determine the equilibrium concentrations in terms of the initial concentrations and change in concentration - use the solubility product expression and Ksp value for the ionic compound to solve for molar solubility
Match the initial moles of weak acid (HA) and strong base (MOH) to the correct stage of an acid-base titration.
- prior to the addition of any base - before the equivalence point - at the equivalence point - beyond the equivalence point
Match each point in a strong acid-base titration with the correct procedure for calculating the pH and/or [H3O+]. Instructions
-Initial pH= [H3O+] = [HA] and pH = -log[H3O+]-Before equivalence point= Moles H3O+ remaining = (initial moles H3O+) - (moles H3O+ reacted); use total volume to calculate new [H3O+] and pH-After equivalence point = Moles excess OH- present = (moles OH- added) - (moles OH- reacted); use total volume to calculate new [OH-]; calculate pH from pOH
Which of the following can NOT be used as an acid-base buffer solution? Select all that apply.
0.5 M HNO3 and 0.5 M NaNO3 0.3 M HCl and 0.3 M NaOH
Rank the following compounds from greatest solubility (top of the list) to lowest solubility (bottom of the list). Instructions Choice 1 of 3. FeS (Ksp= 6.0 x 10-19) toggle button FeS (Ksp = 6.0 x 10-19) Choice 2 of 3. CaCO3(Ksp= 8.7 x 10-9) toggle button CaCO3 (Ksp = 8.7 x 10-9) Choice 3 of 3. BaSO4(Ksp= 1.1 x 10-10) toggle button BaSO4 (Ksp = 1.1 x 10-10)
1. CaCO3 (Ksp= 8.7x10^-9) 2. BaSO4 (Ksp= 1.1x10^-10) 3.FeS (Ksp= 6.3x10^-18) The greater the Ksp, the greater the solubility
Which of the following conditions must be met in order to have a buffer solution?
10 ≥ [conjugate base]/[weak acid] ≥ 0.1
Calculate the molar concentration of Pb2+ ions at equilibrium in an aqueous solution of PbF2(s) if Ksp for PbF2 is 4.1 x 10-8. Assume that the F- ion will not further dissociate in water.
2.2 x 10-3 M Reason: Let [Pb2+] = s, then 4.1 x 10-8 = (s)(2s)2 = 4s3 and s = √34.1 x 10-843 = 2.2 x 10-3 M
Solve for the pH of an aqueous solution containing 0.10 M benzoic acid (C6H5CO2H, K8=6.5 * 10−5).
2.59
The quantity 0.0300 moles is equal to how many millimoles?
3.00 × 101 mmol
Which of the following options correctly expresses the % ionization of a 0.15 M aqueous solution of benzoic acid (C65?
3.1 * 10−3/M0.15 M * 100%
30.0 mL of a 0.15 M solution of the weak acid HClO is titrated with 0.20 M NaOH. Which of the following options correctly reflect how to calculate the pH after the addition of 16.5 mL of NaOH? Select all that apply. (The equivalence point has not yet been reached.) Ka for HClO is equal to 3.0 × 10-6.
3.3 × 10-3 moles of OH- have been added. pH = -log(3.0 × 10-6) + log3.3×10−31.2×10−33.3×10-3 1.2×10-3moles of HClO remain in solution.
Solve for the molar solubility of CaCO3 in a 0.15-M solution of Na2CO3. Ksp (CaCO3) = 8.7 x 10-9.
5.8 x 10-8 M
Which of the following options correctly describes the function of an acid-base buffer?
A buffer minimizes changes in pH when acid or base is added to the solution.
Which of the following options correctly describes an acid-base buffer? Select all that apply.
A buffer resists changes in pH upon addition of small amounts of either an acid or a base. A buffer maintains a relatively narrow pH range of a solution. A buffer is a solution that contains a weak acid and its conjugate base (also weak).
Which of the following steps correctly show how to calculate the molar solubility (s) for Pb(IO3)2(IO3)2 given that Ksp=2.6 * 10−13?Ksp=2.6 * 10-13? Select all that apply.
Assume that [Pb2+] = S, then [IO3-] = 2S.Ksp = 4S3
Which of the following statements correctly describe the equivalence point of a strong acid (HX), strong base (MOH) titration? Select all that apply.
At the equivalence point of a strong acid (HX), strong base (MOH) titration the pH of the solution is 7.000. At the equivalence point of a strong acid (HX), strong base (MOH) titration equimolar amounts of acid and base have reacted.
Calcium sulfate is added to a solution of 0.10 M CaCl2. Which of the following steps are required to calculate the molar solubility of CaSO4? (Select all that apply.)
CaSO4(s) ⇄ Ca2+(aq) + SO42-(aq) Ksp = 4.93 × 10-5 = [Ca2+][SO42-]
Under what conditions will a precipitate form when an aqueous solution of AgNO3 is added to an aqueous solution of NaCl?
If Q > Ksp
The solubility of MgCO3 in water at 25oC is equal to 5.3 x 10-2 g per 100 mL. Select the options that correctly reflect the steps required to calculate Ksp for this compound.
Calculate the molar mass for MgCO3. The molar solubility will give both [Mg2+] and [CO32-]. Calculate molar solubility by converting g/100 mL to mol/L.
Which of the following statements correctly describe how pH and/or hydroxide and hydronium ion concentration influence the solubility of a metal hydroxide (M(OH)nM(OH)n)? M(OH)n (s) ⇌ Mn+ (aq) + nOH− (aq)
Decreasing the pH of solution increases the solubility of M(OH)nM(OH)n. The addition of 0.10 M HCl to the solution increases the solubility of M(OH)n.
Which of the following statements correctly describe fractional precipitation? Select all that apply.
Fractional precipitation entails selectively forming precipitates with specific classes of ions as a means for separation. Fractional precipitation is the separation of a mixture based upon the components' solubilities.
The neutralization of a strong acid (HX) with a strong base (MOH) is correctly represented by which of the following equations? Select all that apply.
H+ (aq) + OH- (aq) → H2O (l) HX (aq) + MOH (aq) → H2O (l) + MX (aq) H3O+ (aq) + OH- (aq) → 2H2O (l)
Addition of ______ ions from the ionization of carbonic acid shifts the equilibrium in favor of ______ oxyhemoglobin molecules and causes the release of oxygen.
H+; unionized
When can Ksp values be used to compare the relative solubilities of two ionic compounds?
If the formulas of the compounds contain the same total number of ions
Calculate the Ksp of Fe(OH)3 given the following equilibrium concentrations: [Fe3+] = 5.0 x 10-10 M and [OH-] = 1.3 x 10-9 M.
Ksp = 1.1 x 10-36 Reason: Ksp = [Fe3+][OH-]3 = (5.0 x 10-10)(1.3 x 10-9)3
Given the following equilibrium table, select the correct equation to solve for the molar solubility, s, of M2X3.
Ksp = 108s5
Match the relationship between Q and Ksp to the correct description.
Q < Ksp: solution is unsaturated and no precipitate forms. Q = Ksp: solution is saturated and no change occurs. Q > Ksp: precipitate forms until solution becomes saturated.
What is the correct equation for the reaction quotient, Q, given the following equilibrium equation? MX2 (s) ⇌ M2+ (aq) + 2X- (aq)
Q = [M2+][X-]2
Which of the following statements correctly defines qualitative analysis?
Qualitative analysis is the determination of the types of ions present in a solution.
Select the options that correctly reflect the steps required to calculate the molar solubility of PbCl2 in 0.15 M NaCl if Ksp for PbCl2 = 2.4 x 10-4.
S = 1.7×10−5(0.15)21.7×10-5(0.15)2 Assume [Pb2+]init = 0. Assume the change in solubility is small, so that [Cl-]eqm = 0.15.
If NaClO (aq) is added to the reaction shown below, which of the following statements would be true? Select all that apply. HClO (aq) + H2O (l) ⇌ ClO- (aq) + H3O+ (aq)
The concentration of HClO (aq) would increase. The pH of the solution would increase.
What conditions must be met in order to have a buffer solution? Select all that apply.
The concentrations of a weak acid and conjugate base differ by less than a factor of 10. The pH of the buffer cannot be more than one pH unit different from the pKa of the weak acid it contains.
Which of the following options correctly describes the common ion effect?
The equilibrium of a dissolved substance shifts due to the addition of another substance containing an ion in common with the dissolved substance.
Which of the following statements correctly describe the titration curve for the titration of a strong acid with a strong base? Select all that apply.
The equivalence point is at a pH of 7.00. The pH rise is very steep close to the equivalence point of the titration.
Which of the following options correctly describe how to calculate the pH at various points during the titration of a weak acid against a strong base? Select all that apply.
The initial [H3O+] is calculated from [HA]in it and Ka. At the equivalence point the pH calculation is based on the reaction of the conjugate base A- with H2O. At the equivalence point, [A-] = initial moles of HA total volume initial moles of HA total volume.
Which of the statements correctly describe the formation constant (Kf) for a complex ion? Select all that apply.
The larger the formation constant, the more stable the complex ion is. The formation constant is the equilibrium constant for the complex ion formation. The formation constant has a value much greater than 1.
Consider a general buffer system made from a weak acid, HA, and its conjugate base A-. Which of the following options correctly describe the behavior of this system when strong acid is added to it? Select all that apply.
The overall pH will decrease only slightly. The ratio [HA]/[A-] will increase. The [A-] in solution will decrease.
Which of the following is true regarding the curve resulting from the titration of a weak base with a strong acid?
The pH at the equivalence point is less than 7.
Which of the following statements correctly reflect the relationship between buffer composition and solution pH given that Ka = [H3O+][A−]/[HA]? Select all that apply.
The pH of the solution depends on the ratio [HA][A−][HA][A-]. If the relative amount of HA is increased, the solution pH will decrease.
What can be shown from the graph?
The pH value at the equivalence point The pKa value of the weak acid The volume of strong base needed to reach the equivalence point
______ have/has a particular tendency to form complex ions.
Transition metals
The solubility of Ag2CrO4 in water is equal to 0.029 g per 1 L of solution at 25oC. Which of the following options correctly reflect the steps required to calculate Ksp for this compound from the given information? Select all that apply.
[CrO42-] = 8.7 x 10-5 M Ksp = 2.5 x 10-12 Molar solubility = 0.029g1L0.029g1L x 1mol331.8g1mol331.8g = 8.7 x 10-5 M Ag2CrO4
50. mL of a 0.15-M solution of NaCl (aq) is mixed with 50. mL of a 0.20-M solution of AgNO3 (aq). Which of the following steps were carried out correctly to determine if a precipitate of AgCl (Ksp = 1.6 x 10-10) forms or not? Select all that apply.
[Na+] = [Cl-] = 0.0075 mol0.100 L0.0075 mol0.100 L = 0.075 M and [Ag+] = [NO3-] = 0.010 mol0.100 L0.010 mol0.100 L = 0.10 M (0.050 L)(0.15 M) = 0.0075 mol NaCl and (0.050 L)(0.20 M) = 0.010 mol AgNO3
150 mL of 0.15 M Na2SO4 is mixed with an equal volume of 0.050 M AgNO3. Select all the options that correctly show the steps used to determine whether or not a precipitate will form, if Ksp for Ag2SO4 = 1.4 x 10-5.
[SO42-] = 7.5 x 10-2 M Q = (0.025)2(0.075)
A buffer is made up using 2.5 L of 0.25 M sodium phenolate (C6H5ONa) and solid phenol (C6H5OH; pKa = 10.0). The desired buffer pH is 9.82. Which of the following options correctly show the calculations required to calculate the mass of phenol needed? Select all that apply.
[phenol] = 0.2510-0.18 Mass of phenol required = 2.5 L x 0.38 mol1 L x 94.11 g1 mol 9.82 = 10.00 + log0.25[phenol]
In a 0.75 M HF solution, the HF is 2.2% dissociated. When NaF (s) is added to this solution the percent dissociation of HF _____ and the pH of the resulting solution will be _____ than its original value. This effect is due to the addition of the common ion _____.
decreases; higher; F-
When Na2CO3 is added to a saturated solution of BaCO3, the equilibrium will shift by _____ the amount of barium ions in solution, thus _____ the solubility of BaCO3.
decreasing; decreasing
The _____ point of a titration is the point at which the indicator changes color. The indicator is chosen so that the color change occurs at a pH as close as possible to the pH of the ______ point.
end, equivalence
A measure of the tendency of a metal ion to form a particular complex ion is given by the ______ constant.
formation
The practice of separating ions in a solution by selectively precipitating certain ions out of the solution by chemically converting them into insoluble species is known as ______ precipitation.
fractional
A chemist titrates a 25.00-mL portion of 0.15 M HCl with a 0.20 M solution of KOH. Which of the following options correctly describe how to calculate the pH at the beginning of this titration AND after 15.00 mL of base has been added? Select all that apply.
initial pH = -log(0.15) = 0.82 [H3O+] after base has been added = 7.5×10−40.0400L7.5×10-40.0400L initial moles of H3O+ = 3.75 x 10-3
For ionic compounds that have the same total number of _____ in their formulas, the larger the Ksp value, the _____ soluble the compound.
ions, more
Consider the equilibrium system NH3 (aq) + H2O (l) ⇌ NH4+ (aq) + OH- (aq). If some solid NH4Cl were added to the system, the equilibrium would shift to the _____ and the [OH-] would _____.
left; decrease
Which of the following equalities are correct at the equivalence point of a strong acid-strong base titration? Select all that apply.
moles OH- = moles H3O+ [OH-] = [H3O+] pH = 7.000
Which of the following equalities are correct at the equivalence point of a strong acid-weak base titration? Select all that apply.
moles weak base = moles H3O+ pH < 7.000
Consider a buffer solution consisting of 0.35 M HNO2 and 0.50 M KNO2, which has an initial pH of 3.30 (Ka for HNO2 = 7.1 x 10-4). If 0.030 mol of HCl are added to 1.0 L of this solution, select all the options that correctly reflect the steps required to calculate the change in pH.
pH = -log(7.1×10−4×0.380.47)7.1×10-4×0.38/0.47 = 3.24 [H3O+] = 7.1 x 10-4 x 0.38/0.47
A buffer solution consists of 0.23 M HF and 0.31 M NaF (pKa for HF = 3.18). Which option shows the correct calculation for the pH of the buffer using the Henderson-Hasselbalch equation after 0.010 mol of HCl is added to 1.0 L of the solution?
pH = 3.18 + log0.30/0.24 Reason: The 0.010 mol of HCl reacts with F- so that [F-]new = 0.30 M. [HF]new = 0.24 M.
Consider a buffer made by combining equal volumes of 0.15 M CH3COOH and 0.32 M NaC2H3O2. What is the pH of this buffer if the Ka for CH3COOH is 1.8 x 10-5?
pH = 5.07 Reason: pH = -log(1.8 x 10-5) + log0.32/0.15 = 4.74 + 0.33 = 5.07
Consider a buffer consisting of a weak acid (HA) and the corresponding conjugate base (A-). The buffer initially contains equal amounts of HA and A-. Match each picture to the correct representation of the buffer after the change indicated.
strong acid has been added = A strong base has been added = B
In acid base titration, the is ______ the solution that is added from the burette into the titration vessel.
titrant
A buffer used in food products is the benzoic acid/benzoate buffer, which has a pKa = 4.19. If you need to maintain a pH of 3.50 using this buffer system, what concentration of benzoate ion would you need if you have 0.05 M benzoic acid?
0.01 M Benzoate ion 3.50 = 4.19 + log[benzoate]\0.05 so [benzoate]/0.05 = 10^-0.69 and [benzoate] = 0.05 x 10^-0.69 = 0.01 M
1 mmol is equal to which of the following? Select all that apply.
1 M x 10-3 L 1 M x 1 mL
AgNO3AgNO3 is added to a solution that contains 0.010 M I- ions and 0.010 M Br-ions. Calculate the concentration of Ag+ ions required to initiate the precipitation of AgI (Ksp=8.3 * 10-17) without precipitating AgBr (Ksp=7.7 * 10-13).
8.3 * 10−15 M < [Ag+] < 7.7 * 10−11 M
What is the pH of a solution containing both 0.200 M NH3 and 0.300 M NH4Cl? Ka for NH4+ is equal to 5.60 x 10-10.
9.08
Calculate the pH of a saturated Zn(OH)2Zn(OH)2 solution. ksp (Zn(OH)2) = 1.8 × 10−14ksp (Zn(OH)2) = 1.8 × 10-14.
9.53 Reason: In a solution with a pH of less than 9.53 the solubility of Zn(OH)2Zn(OH)2 would increase.
Solve for the molar solubility of AgCl in a 0.20-M solution of Na2S2O3. AgCl (s) + 2S2O32- (aq) ⇌ Ag(S2O3)23- (aq) + Cl- (aq) Koverall = 7.5 x 103
9.9 x 10-2 M
Which of the following statements correctly describe the equivalence point of a strong acid-weak base titration? Select all that apply.
At the equivalence point of a strong acid-weak base titration [H3O+] > 1.0 x 10-7 M. At the equivalence point of a strong acid (HA)-weak base (NH3) titration equimolar amounts of acid and base have reacted.
Which of the following statements correctly describe the equivalence point of a weak acid (HA), strong base (MOH) titration? Select all that apply.
At the equivalence point of a weak acid-strong base titration equimolar amounts of acid and base have reacted. At the equivalence point of a weak acid-strong base titration [OH-] > 1.0 x 10-7 M.
Match each slightly soluble salt with the correct Ksp expression.
Fe(OH)2 = Ksp = [Fe2+][OH-]2 Fe(OH)3 = Ksp = [Fe3+][OH-]3
Which of the following salts will dissolve more readily in aqueous nitric acid than in pure H2O? Select all that apply.
Fe(OH)3 CaCO3 Zn3(PO4)2
In a standard qualitative analysis scheme, cations in solution can be separated by stepwise addition of precipitating agents. Place the precipitating agents in the correct order for this procedure, starting with the first compound added at the top of the list. Instructions Choice 1 of 4. NaOH toggle button NaOH Choice 2 of 4. HCl toggle button HCl Choice 3 of 4. Na2CO3 toggle button Na2CO3 Choice 4 of 4. H2S toggle button H2S
HCl H2S NaOH Na2CO3
The neutralization of a strong acid with a strong base is correctly represented by which of the following equations? Select all that apply.
HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) HBr (aq) + KOH (aq) → KBr (aq) + H2O (l)
What are the principal buffer systems found in blood plasma and/or red blood cells? Select all that apply.
HHb (hemoglobin)/Hb−Hb- H2CO3/HCO3−
Which of the following combinations could be used in an acid-base buffer system? Select all that apply.
HNO2 /KNO2 CH3COOH/NaCH3COO NH3 /NH4Cl
Which of the following equations correctly represent the neutralization of the weak base, ammonia (NH3), with the strong acid, nitric acid (HNO3)? Select all that apply.
HNO3 (aq) + NH3 (aq) → NH4NO3 (aq) H3O+ (aq) + NH3 (aq) → NH4+ (aq) + H2O (l)
AgNO3 is added to a solution that contains 0.030 M IO3- ions and 0.030 M BrO3- ions. Which of the following steps are required to calculate the concentration of Ag+ ions required to initiate the precipitation of AgIO3 (Ksp= 3.17 x 10-8) without precipitating AgBrO3 (Ksp = 5.38 x 10-5)? (Select all that apply.)
Ksp = [Ag+] [BrO3-] = 5.38 x 10-5 Ksp = [Ag+] [IO3-] = 3.17 x 10-8
Which of the following is the correct Ksp expression for the dissolution: Al(OH)3 (s) ⇌ Al3+ (aq) + 3OH- (aq)?
Ksp = [Al3+][OH-]3
For the process, MnX (s) ⇌ nM+ (aq)+ Xn- (aq), what is the correct Ksp expression?
Ksp = [M+]n[Xn-]
Match each saturated aqueous solution to the corresponding undissolved solid to complete each equilibrium.
MX (s) ⇌M+(aq) + X-(aq) MX2 (s) ⇌M2+(aq) + 2X-(aq) M2X (s) ⇌ 2M+(aq) + X2-(aq) M2X3 (s) ⇌2M3+(aq) + 3X2-(aq)
Which of the following statements correctly describe the molar solubility of a slightly soluble ionic compound?
Molar solubility is the number of moles of solute in 1 L of a saturated solution.
25.0 mL of a 0.20 M solution of the weak acid CH3COOH (Ka = 1.8 × 10-5) is titrated with 0.25 M NaOH. Place the steps required to calculate the pH at the equivalence point in the correct order, starting with the first step at the top of the list.
Mole volume CH3 OH- pH
A chemist titrates a 25.00-mL portion of 0.25 M HNO3 with a 0.25 M solution of NaOH. Which of the following options correctly reflect the steps required to calculate the pH once 35.00 mL of NaOH has been added? Select all that apply.
Moles of OH- added = 8.75 × 10-3 pH = 12.62 Moles of OH- in excess = 2.5 × 10-3
Select the correct expression to calculate the molar solubility of Ag3PO4 in water at 25oC if Ksp = 2.6 x 10-18.
S = 4√ 2.6×10−1827
Consider the dissociation of the weak acid HClO2, which can be represented by the balanced equation HClO2 (aq) + H2O (l) ⇌ ClO2- (aq) + H3O+ (aq). Which of the following options correctly describe the effect of adding solid KClO2 to this system? Select all that apply.
The % dissociation of HClO2 will decrease. The solution pH will increase.
Which of the following statements correctly describe how to name an ester? Select all that apply.
The -ic ending of the parent carboxylic acid is replaced by the suffix -ate. The alkyl and acyl portions of the ester structure are named separately. The portion of the ester directly bonded to the oxygen atom is named as an alkyl (or aryl) group, with the -yl ending. The alkyl portion is named first, followed by the name for the acyl portion.
Which of the following should be considered when selecting/preparing a buffer solution? Select all that apply.
The pKa of the acid component of the buffer should be close to the desired pH. The pH of the buffer depends on the ratio of acid and base concentrations. The acid and conjugate base used must both be weak.
Compared to the titration curve for titration of a strong base with a strong acid, the curve for titration of a weak base with a strong acid has which of the following features? Select all that apply.
a more acidic equivalence point a shorter vertical region near the equivalence point
In solution, an acid-base indicator can be represented by the following equilibrium where HIn and its conjugate base, In-, have distinctly different colors. HIn (aq) + H2O (l) ⇌ H3O+ (aq) + In- (aq) Match each type of medium to the expected color of solution based on the ionization of the indicator.
acidic medium: color of the solution will be that of HIn basic medium: the color of the solution will be that of In-
In an experiment, an aqueous solution of base is slowly added from a burette to a vessel containing an acid with a known concentration and volume. Which substance in this experiment is the titrant?
base
Place the steps for preparing a buffer in the correct order, beginning with the first step at the top of the list.
chose use convert mix
The pH of a saturated metal hydroxide solution is 11.12. If the pH were 11.50, the solubility of the metal hydroxide in solution would ______.
decrease Reason: Increasing the pH means more OH−OH- ions in solution, which would push the equilibrium of the metal hydroxide towards the reactants side or increase the amount of solid metal hydroxide.
When calculating the pH of a saturated metal hydroxide solution X(OH)2, which of the following calculations and equations are required? (Select all that apply.)
pH = 14 − pOH OR [H+] = Kw[OH−][H+] = Kw[OH-] X(OH)2 (s) ⇆ X2+ (aq) + 2OH− (aq)
25.0 mL of 0.250 M HCl is titrated with a 0.125 M solution of the weak base aniline (C6H5NH2; Kb = 3.80 x 10-10). The equivalence point is reached when 50.0 mL of base has been added. Which of the following options correctly reflect the steps required to calculate the pH at the equivalence point? Select all that apply.
pH = 2.82 [C6H5NH3+] at the equivalence point = 6.25x10-30.025+0.050L6.25x10-30.025+0.050L = 8.33 x 10-2 M Ka of the conjugate acid C6H5NH3+ = 2.63 x 10-5
Which of the following is the correct form of the Henderson-Hasselbalch equation?
pH = pKa + log[conjugate base]/[weak acid]
Which of the following equalities are correct at the equivalence point of a weak acid (HA), strong base (MOH) titration? Select all that apply.
pH > 7.000 moles HA = moles OH-
Which of the following correctly describes the reaction below? H3O+(aq) + B(aq) → BH+(aq) + H2O(l)
strong acid-weak base neutralization
