Question 1

Which of the following is TRUE?

Accepted Answer

A) The equivalence point is where the amount of acid equals the amount of base during any acid-base titration. 
B) At the equivalence point,the pH is always 7. 
C) An indicator is not pH sensitive. 
D) A titration curve is a plot of pH vs.the [base]/[acid] ratio. 
E) A titration curve is a plot of pH versus titration time. 
A) The equivalence point is where the amount of acid equals the amount of base during any acid-base titration. 
B) At the equivalence point,the pH is always 7. 
C) An indicator is not pH sensitive. 
D) A titration curve is a plot of pH vs.the [base]/[acid] ratio. 
E) A titration curve is a plot of pH versus titration time.

Question 2

Calculate the pH of a solution that is 0.240 mol L-1 in nitrous acid ( $\mathrm { HNO } _ { 2 }$ )and 0.320 mol L-1 in potassium nitrite ( $\mathrm { KNO } _ { 2 }$ ).The acid dissociation constant of nitrous acid is 4.50 × $10 ^ { - 4 }$ .

Accepted Answer

A) 12.885 
B) 4.461 
C) 3.222 
D) 10.528 
E) 3.472 
A) 12.885 
B) 4.461 
C) 3.222 
D) 10.528 
E) 3.472

Question 3

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L-1 HCOOH with 100.0 mL of 0.20 mol L-1 HCOOLi.The Ka for HCHO2 is 1.8 × 10-4.

Accepted Answer

A) 3.87 
B) 3.74 
C) 10.53 
D) 3.47 
E) 10.13 
A) 3.87 
B) 3.74 
C) 10.53 
D) 3.47 
E) 10.13

Question 4

Identify the most commonly used indicator among the following five.

Accepted Answer

A) alizarin 
B) thymol blue 
C) crystal violet 
D) phenolphthalein 
E) alizarin yellow R 
A) alizarin 
B) thymol blue 
C) crystal violet 
D) phenolphthalein 
E) alizarin yellow R

Question 5

Determine the molar solubility of AgBr in a solution containing 0.150 mol L-1 NaBr.Ksp (AgBr)= 7.7 × 10-13.

Accepted Answer

A) 8.8 × 10-7 mol L-1 
B) 3.9 × 10-13 mol L-1 
C) 5.8 × 10-5 mol L-1 
D) 5.1 × 10-12 mol L-1 
E) 0.150 mol L-1 
A) 8.8 × 10-7 mol L-1 
B) 3.9 × 10-13 mol L-1 
C) 5.8 × 10-5 mol L-1 
D) 5.1 × 10-12 mol L-1 
E) 0.150 mol L-1

Question 6

How many millilitres of 0.120 mol L-1 NaOH are required to titrate 50.0 mL of 0.0998 mol L-1 acetic acid to the equivalence point? Acetic acid is monoprotic.The $K _ { a }$ of acetic acid is 1.8 × 10-5.

Accepted Answer

A) 41.6 
B) 60.1 
C) 50.0 
D) 1.77 
E) 2.82 
A) 41.6 
B) 60.1 
C) 50.0 
D) 1.77 
E) 2.82

Question 7

Calculate the percent ionization of nitrous acid in a solution that is 0.210 mol L-1 in nitrous acid $\left( \mathrm { HNO } _ { 2 } \right)$ and 0.290 mol L-1 in potassium nitrite ( $\mathrm { KNO } _ { 2 }$ ).The acid dissociation constant of nitrous acid is $4.50 \times 10 ^ { - 4 }$

Accepted Answer

A) 58.0 
B) 0.154 
C) 16.6 
D) 2.74 × $10 ^ { - 3 }$ 
E) 1.55 
A) 58.0 
B) 0.154 
C) 16.6 
D) 2.74 × $10 ^ { - 3 }$ 
E) 1.55

Question 8

Calculate the Ksp for silver carbonate if the solubility of Ag2CO3 in pure water is 3.5 × 10-2 g L-1.

Accepted Answer

A) 2.1 × 10-12 
B) 8.2 × 10-12 
C) 1.6 × 10-8 
D) 3.2 × 10-8 
A) 2.1 × 10-12 
B) 8.2 × 10-12 
C) 1.6 × 10-8 
D) 3.2 × 10-8

Question 9

Identify the compound that is acid-insoluble.

Accepted Answer

A) PbCl2 
B) As2S3 
C) CoS 
D) Ca3(PO4)2 
E) NaCl 
A) PbCl2 
B) As2S3 
C) CoS 
D) Ca3(PO4)2 
E) NaCl

Question 10

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH)requires 29.80 mL of 0.3567 mol L-1 NaOH? Ka =1.8 × 10-4   for formic acid.

Accepted Answer

A) 2.06 
B) 5.48 
C) 8.52 
D) 11.94 
A) 2.06 
B) 5.48 
C) 8.52 
D) 11.94

Question 11

Which of the following acids (listed with pKa values)and its conjugate base could form a buffer with a pH of 8.10?

Accepted Answer

A) HC7H5O2,pKa = 4.19 
B) HF,pKa = 3.46 
C) HClO,pKa = 7.54 
D) HCN,pKa = 9.31 
E) HClO2,pKa = 1.96 
A) HC7H5O2,pKa = 4.19 
B) HF,pKa = 3.46 
C) HClO,pKa = 7.54 
D) HCN,pKa = 9.31 
E) HClO2,pKa = 1.96

Question 12

You wish to prepare a buffer containing CH3COOH with a pH of 4.24.If the pKa of acetic acid is 4.74,what ratio of [CH3COO-]/[CH3COOH] must you use?

Accepted Answer

A) 0.10 
B) 0.50 
C) 0.32 
D) 2.0 
E) 2.8 
A) 0.10 
B) 0.50 
C) 0.32 
D) 2.0 
E) 2.8

Question 13

Which of the following compounds will be more soluble in acidic solution than in pure water?

Accepted Answer

A) PbCl2 
B) FeS 
C) Ca(ClO4)2 
D) CuI 
E) AgBr 
A) PbCl2 
B) FeS 
C) Ca(ClO4)2 
D) CuI 
E) AgBr

Question 14

Identify the indicator that can be used at the lowest pH.

Accepted Answer

A) alizarin 
B) thymol blue 
C) crystal violet 
D) phenolphthalein 
E) alizarin yellow R 
A) alizarin 
B) thymol blue 
C) crystal violet 
D) phenolphthalein 
E) alizarin yellow R

Question 15

Identify the expression for the solubility product constant for Ca3(PO4)2.

Accepted Answer

A)  $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } } { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] }$ 
B)  $\frac { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] } { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } }$ 
C)  $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 2 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 3 } } { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] }$ 
D) [Ca2+]2[PO43-]3 
E) [Ca2+]3[PO43-]2 
A)  $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } } { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] }$ 
B)  $\frac { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] } { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } }$ 
C)  $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 2 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 3 } } { \left[ \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } \right] }$ 
D) [Ca2+]2[PO43-]3 
E) [Ca2+]3[PO43-]2

Question 16

What is the pH of the resulting solution if 45 mL of 0.432 mol L-1 methylamine,CH3NH2,is added to 15 mL of 0.234 mol L-1 HCl? Assume that the volumes of the solutions are additive.Ka = 2.70 × 10-11 for CH3NH3+.

Accepted Answer

A) 2.77 
B) 4.09 
C) 9.91 
D) 11.23 
A) 2.77 
B) 4.09 
C) 9.91 
D) 11.23

Question 17

A sample contains Ba3(PO4)2, CdS,AgCl,NH4Cl,and ZnS.Identify the precipitate after the addition of 6 mol L-1 HCl; H2S and 0.2 mol L-1 HCl; OH- to a pH of 8; and (NH4)2HPO4 with NH3.

Accepted Answer

A) Ba3(PO4)2 
B) CdS 
C) AgCl 
D) NH4Cl 
E) ZnS 
A) Ba3(PO4)2 
B) CdS 
C) AgCl 
D) NH4Cl 
E) ZnS

Question 18

Define buffer capacity.

Accepted Answer

A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness. 
B) Buffer capacity is the amount of acid that can be added until all the base in the buffer is consumed. 
C) Buffer capacity is the amount of base that can be added until all the acid in the buffer is consumed. 
D) Buffer capacity is the amount of acid that can be added until all the acid in the buffer is consumed. 
E) Buffer capacity is the amount of base that can be added until all the base in the buffer is consumed. 
A) Buffer capacity is the amount of acid or base that can be added to a buffer without destroying its effectiveness. 
B) Buffer capacity is the amount of acid that can be added until all the base in the buffer is consumed. 
C) Buffer capacity is the amount of base that can be added until all the acid in the buffer is consumed. 
D) Buffer capacity is the amount of acid that can be added until all the acid in the buffer is consumed. 
E) Buffer capacity is the amount of base that can be added until all the base in the buffer is consumed.

Question 19

Which of the following acids (listed with Ka values)and their conjugate base would be the best choice to make a buffer with a pH of 2.34?

Accepted Answer

A) C6H5COOH,Ka = 6.5 × 10-5 
B) HF,Ka = 3.5 × 10-4 
C) HClO,Ka = 2.9 × 10-8 
D) HCN,Ka = 4.9 × 10-10 
E) HClO2,Ka = 1.1 × 10-2 
A) C6H5COOH,Ka = 6.5 × 10-5 
B) HF,Ka = 3.5 × 10-4 
C) HClO,Ka = 2.9 × 10-8 
D) HCN,Ka = 4.9 × 10-10 
E) HClO2,Ka = 1.1 × 10-2

Question 20

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH? Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3COOH

Accepted Answer

A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57 
A) 9.43 
B) 9.08 
C) 4.92 
D) 4.57

Exam 16: Aqueous Ionic Equilibrium

Which of the following is TRUE?

Calculate the pH of a solution that is 0.240 mol L-1 in nitrous acid ( HNO2\mathrm { HNO } _ { 2 }HNO2​ )and 0.320 mol L-1 in potassium nitrite ( KNO2\mathrm { KNO } _ { 2 }KNO2​ ).The acid dissociation constant of nitrous acid is 4.50 × 10−410 ^ { - 4 }10−4 .

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L-1 HCOOH with 100.0 mL of 0.20 mol L-1 HCOOLi.The Ka for HCHO2 is 1.8 × 10-4.

Identify the most commonly used indicator among the following five.

Determine the molar solubility of AgBr in a solution containing 0.150 mol L-1 NaBr.Ksp (AgBr)= 7.7 × 10-13.

How many millilitres of 0.120 mol L-1 NaOH are required to titrate 50.0 mL of 0.0998 mol L-1 acetic acid to the equivalence point? Acetic acid is monoprotic.The KaK _ { a }Ka​ of acetic acid is 1.8 × 10-5.

Calculate the Ksp for silver carbonate if the solubility of Ag2CO3 in pure water is 3.5 × 10-2 g L-1.

Identify the compound that is acid-insoluble.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH)requires 29.80 mL of 0.3567 mol L-1 NaOH? Ka =1.8 × 10-4 for formic acid.

Which of the following acids (listed with pKa values)and its conjugate base could form a buffer with a pH of 8.10?

You wish to prepare a buffer containing CH3COOH with a pH of 4.24.If the pKa of acetic acid is 4.74,what ratio of [CH3COO-]/[CH3COOH] must you use?

Which of the following compounds will be more soluble in acidic solution than in pure water?

Identify the indicator that can be used at the lowest pH.

Identify the expression for the solubility product constant for Ca3(PO4)2.

What is the pH of the resulting solution if 45 mL of 0.432 mol L-1 methylamine,CH3NH2,is added to 15 mL of 0.234 mol L-1 HCl? Assume that the volumes of the solutions are additive.Ka = 2.70 × 10-11 for CH3NH3+.

A sample contains Ba3(PO4)2, CdS,AgCl,NH4Cl,and ZnS.Identify the precipitate after the addition of 6 mol L-1 HCl; H2S and 0.2 mol L-1 HCl; OH- to a pH of 8; and (NH4)2HPO4 with NH3.

Define buffer capacity.

Which of the following acids (listed with Ka values)and their conjugate base would be the best choice to make a buffer with a pH of 2.34?

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L-1 acetic acid is added to 10.00 mL of 0.10 mol L-1 NaOH? Assume that the volumes of the solutions are additive.Ka = 1.8 × 10-5 for CH3COOH

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Calculate the pH of a solution that is 0.240 mol L^-1 in nitrous acid ( $\mathrm { HNO } _ { 2 }$ )and 0.320 mol L^-1 in potassium nitrite ( $\mathrm { KNO } _ { 2 }$ ).The acid dissociation constant of nitrous acid is 4.50 × $10 ^ { - 4 }$ .

Calculate the pH of a solution formed by mixing 250.0 mL of 0.15 mol L^-1 HCOOH with 100.0 mL of 0.20 mol L^-1 HCOOLi.The K_a for HCHO₂ is 1.8 × 10^-4.

Determine the molar solubility of AgBr in a solution containing 0.150 mol L^-1 NaBr.K_sp (AgBr)= 7.7 × 10^-13.

How many millilitres of 0.120 mol L^-1 NaOH are required to titrate 50.0 mL of 0.0998 mol L^-1 acetic acid to the equivalence point? Acetic acid is monoprotic.The $K _ { a }$ of acetic acid is 1.8 × 10^-5.

Calculate the K_sp for silver carbonate if the solubility of Ag₂CO₃ in pure water is 3.5 × 10^-2g L^-1.

What is the approximate pH at the equivalence point of a weak acid-strong base titration if 25 mL of aqueous formic acid (HCOOH)requires 29.80 mL of 0.3567 mol L^-1 NaOH? K_a =1.8 × 10^-4 for formic acid.

Which of the following acids (listed with pK_a values)and its conjugate base could form a buffer with a pH of 8.10?

You wish to prepare a buffer containing CH₃COOH with a pH of 4.24.If the pK_a of acetic acid is 4.74,what ratio of [CH₃COO^-]/[CH₃COOH] must you use?

Identify the expression for the solubility product constant for Ca₃(PO₄)₂.

What is the pH of the resulting solution if 45 mL of 0.432 mol L^-1 methylamine,CH₃NH₂,is added to 15 mL of 0.234 mol L^-1 HCl? Assume that the volumes of the solutions are additive.K_a = 2.70 × 10^-11for CH₃NH₃⁺.

A sample contains Ba₃(PO₄)₂,CdS,AgCl,NH₄Cl,and ZnS.Identify the precipitate after the addition of 6 mol L^-1 HCl; H₂S and 0.2 mol L^-1 HCl; OH^-to a pH of 8; and (NH₄)₂HPO₄ with NH₃.

Which of the following acids (listed with K_a values)and their conjugate base would be the best choice to make a buffer with a pH of 2.34?

What is the pH of the resulting solution if 25.00 mL of 0.10 mol L^-1 acetic acid is added to 10.00 mL of 0.10 mol L^-1 NaOH? Assume that the volumes of the solutions are additive.K_a = 1.8 × 10^-5for CH₃COOH