Question 1

A 100.0 mL sample of 0.180 mol L-1 HClO4 is titrated with 0.270 mol L-1 NaOH. Determine the pH of the solution after the addition of 75.0 mL of NaOH.

Accepted Answer

A) 12.1 
B) 2.65 
C) 11.35 
D) 1.89 
E) 13.06 
A) 12.1 
B) 2.65 
C) 11.35 
D) 1.89 
E) 13.06

Question 2

Identify the compound that forms stalactites and stalagmites.

Accepted Answer

Calcium ca

Question 3

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 4

A solution of NaF is added dropwise to a solution that is 0.0144 mol L-1 in Ba2+. When the concentration of F- exceeds ________ mol L-1, BaF2 will precipitate. Neglect volume changes. For BaF2, Ksp = 1.7 × 10-6.

Accepted Answer

A) 5.9 × 10-5 
B) 1.1 × 10-2 
C) 2.4 × 10-8 
D) 2.7 × 10-3 
E) 1.2 × 10-4 
A) 5.9 × 10-5 
B) 1.1 × 10-2 
C) 2.4 × 10-8 
D) 2.7 × 10-3 
E) 1.2 × 10-4

Question 5

Describe the information necessary (and why)to choose a good indicator for a weak acid-strong base titration.

Accepted Answer

In order to choose an appropriate indica

Question 6

Which one of the following statements is TRUE?

Accepted Answer

A) A buffer is an aqueous solution composed of two weak acids. 
B) A buffer can absorb an unlimited amount of acid or base. 
C) A buffer resists pH change by neutralizing added acids and bases. 
D) A buffer does not change pH when large amounts of a strong acid or a strong base are added. 
E) The common ion in a buffer solution does not have any effect on the dissociation of the acidic component of the buffer solution. 
A) A buffer is an aqueous solution composed of two weak acids. 
B) A buffer can absorb an unlimited amount of acid or base. 
C) A buffer resists pH change by neutralizing added acids and bases. 
D) A buffer does not change pH when large amounts of a strong acid or a strong base are added. 
E) The common ion in a buffer solution does not have any effect on the dissociation of the acidic component of the buffer solution.

Question 7

A 100.0 mL sample of 0.18 mol L-1 HClO4 is titrated with 0.27 mol L-1 NaOH. Determine the pH of the solution after the addition of 30.0 mL of NaOH.

Accepted Answer

A) 0.86 
B) 1.21 
C) 2.00 
D) 1.12 
E) 2.86 
A) 0.86 
B) 1.21 
C) 2.00 
D) 1.12 
E) 2.86

Question 8

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 9

What is the pH of a buffer solution that is 0.255 mol L-1 in hypochlorous acid (HClO)and 0.333 mol L-1 in sodium hypochlorite (NaClO)? The Ka of hypochlorous acid is 3.8 × 10-8.

Accepted Answer

A) 13.88 
B) 6.46 
C) 8.49 
D) 7.30 
E) 7.54 
A) 13.88 
B) 6.46 
C) 8.49 
D) 7.30 
E) 7.54

Question 10

Calculate the pH of a solution that is 0.295 mol L-1 in sodium formate (HCOONa)and 0.205 mol L-1 in formic acid (HCOOH). The Ka of formic acid is 1.77 × 10-4.

Accepted Answer

A) 3.910 
B) 3.587 
C) 13.84 
D) 10.10 
E) 4.963 
A) 3.910 
B) 3.587 
C) 13.84 
D) 10.10 
E) 4.963

Question 11

A 1.00 L buffer solution is 0.150 mol L-1 in C6H5COOH and 0.250 mol L-1 in C6H5COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L-1 HCl. The Ka for HC7H5O2 is 6.5 × 10-5.

Accepted Answer

A) 4.19 
B) 5.03 
C) 4.41 
D) 3.34 
E) 3.97 
A) 4.19 
B) 5.03 
C) 4.41 
D) 3.34 
E) 3.97

Question 12

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 13

Formic acid (HCOOH, Ka = 1.8 × 10-4)is the principal component in the venom of stinging ants. What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L-1 NaOH to reach the equivalence point?

Accepted Answer

A) 0.0134 mol L-1 
B) 0.0476 mol L-1 
C) 0.0567 mol L-1 
D) 0.0676 mol L-1 
A) 0.0134 mol L-1 
B) 0.0476 mol L-1 
C) 0.0567 mol L-1 
D) 0.0676 mol L-1

Question 14

When titrating a weak monoprotic acid with NaOH at 25 °C, the

Accepted Answer

A) pH will be less than 7 at the equivalence point. 
B) pH will be equal to 7 at the equivalence point. 
C) pH will be greater than 7 at the equivalence point. 
D) titration will require more moles of base than acid to reach the equivalence point. 
E) titration will require more moles of acid than base to reach the equivalence point. 
A) pH will be less than 7 at the equivalence point. 
B) pH will be equal to 7 at the equivalence point. 
C) pH will be greater than 7 at the equivalence point. 
D) titration will require more moles of base than acid to reach the equivalence point. 
E) titration will require more moles of acid than base to reach the equivalence point.

Question 15

A 100.0 mL sample of 0.10 mol L-1 Ca(OH)2 is titrated with 0.10 mol L-1 HBr. Determine the pH of the solution after the addition of 300.0 mL HBr.

Accepted Answer

A) 1.60 
B) 1.30 
C) 1.00 
D) 12.40 
E) 1.12 
A) 1.60 
B) 1.30 
C) 1.00 
D) 12.40 
E) 1.12

Question 16

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 17

A solution is prepared by dissolving 0.23 mol of hydrazoic acid and 0.27 mol of sodium azide in water sufficient to yield 1.00 L of solution.The addition of 0.05 mol of NaOH to this buffer solution causes the pH to increase slightly. The pH does not increase drastically because the NaOH reacts with the ________ present in the buffer solution. The Ka of hydrazoic acid is 1.9 × 10-5.

Accepted Answer

A) H2O 
B) H3O+ 
C) azide 
D) hydrazoic acid 
E) This is a buffer solution: the pH does not change upon addition of acid or base. 
A) H2O 
B) H3O+ 
C) azide 
D) hydrazoic acid 
E) This is a buffer solution: the pH does not change upon addition of acid or base.

Question 18

What is the molar solubility of barium fluoride (BaF2)in water? The solubility-product constant for BaF2 is 1.7 × 10-6 at 25 °C.

Accepted Answer

A) 6.5 × 10-4 mol L-1 
B) 1.2 × 10-2 mol L-1 
C) 1.8 × 10-3 mol L-1 
D) 7.5 × 10-3 mol L-1 
E) 5.7 × 10-7 mol L-1 
A) 6.5 × 10-4 mol L-1 
B) 1.2 × 10-2 mol L-1 
C) 1.8 × 10-3 mol L-1 
D) 7.5 × 10-3 mol L-1 
E) 5.7 × 10-7 mol L-1

Question 19

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH. Determine the pH of the solution after the addition of 100.0 mL of KOH. The Ka of HF is 3.5 × 10-4.

Accepted Answer

A) 2.08 
B) 3.15 
C) 4.33 
D) 3.46 
E) 4.15 
A) 2.08 
B) 3.15 
C) 4.33 
D) 3.46 
E) 4.15

Question 20

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 150.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

Accepted Answer

A) 1.7 
B) 6.4 
C) 7.6 
D) 12.3 
E) 2.3 
A) 1.7 
B) 6.4 
C) 7.6 
D) 12.3 
E) 2.3

Exam 16: Aqueous Ionic Equilibrium

A 100.0 mL sample of 0.180 mol L-1 HClO4 is titrated with 0.270 mol L-1 NaOH. Determine the pH of the solution after the addition of 75.0 mL of NaOH.

Identify the compound that forms stalactites and stalagmites.

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.

A solution of NaF is added dropwise to a solution that is 0.0144 mol L-1 in Ba2+. When the concentration of F- exceeds ________ mol L-1, BaF2 will precipitate. Neglect volume changes. For BaF2, Ksp = 1.7 × 10-6.

Describe the information necessary (and why)to choose a good indicator for a weak acid-strong base titration.

Which one of the following statements is TRUE?

A 100.0 mL sample of 0.18 mol L-1 HClO4 is titrated with 0.27 mol L-1 NaOH. Determine the pH of the solution after the addition of 30.0 mL of NaOH.

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 a buffer solution that is 0.255 mol L-1 in hypochlorous acid (HClO)and 0.333 mol L-1 in sodium hypochlorite (NaClO)? The Ka of hypochlorous acid is 3.8 × 10-8.

Calculate the pH of a solution that is 0.295 mol L-1 in sodium formate (HCOONa)and 0.205 mol L-1 in formic acid (HCOOH). The Ka of formic acid is 1.77 × 10-4.

A 1.00 L buffer solution is 0.150 mol L-1 in C6H5COOH and 0.250 mol L-1 in C6H5COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L-1 HCl. The Ka for HC7H5O2 is 6.5 × 10-5.

Define buffer capacity.

Formic acid (HCOOH, Ka = 1.8 × 10-4)is the principal component in the venom of stinging ants. What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L-1 NaOH to reach the equivalence point?

When titrating a weak monoprotic acid with NaOH at 25 °C, the

A 100.0 mL sample of 0.10 mol L-1 Ca(OH)2 is titrated with 0.10 mol L-1 HBr. Determine the pH of the solution after the addition of 300.0 mL HBr.

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.

What is the molar solubility of barium fluoride (BaF2)in water? The solubility-product constant for BaF2 is 1.7 × 10-6 at 25 °C.

A 100.0 mL sample of 0.20 mol L-1 HF is titrated with 0.10 mol L-1 KOH. Determine the pH of the solution after the addition of 100.0 mL of KOH. The Ka of HF is 3.5 × 10-4.

A 100.0 mL sample of 0.10 mol L-1 NH3 is titrated with 0.10 mol L-1 HNO3. Determine the pH of the solution after the addition of 150.0 mL of HNO3. The Kb of NH3 is 1.8 × 10-5.

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A 100.0 mL sample of 0.180 mol L^-1 HClO₄ is titrated with 0.270 mol L^-1 NaOH. Determine the pH of the solution after the addition of 75.0 mL of NaOH.

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.

A solution of NaF is added dropwise to a solution that is 0.0144 mol L^-1 in Ba²⁺. When the concentration of F^- exceeds ________ mol L^-1, BaF₂ will precipitate. Neglect volume changes. For BaF₂, K_sp = 1.7 × 10^-6.

A 100.0 mL sample of 0.18 mol L^-1 HClO₄ is titrated with 0.27 mol L^-1 NaOH. Determine the pH of the solution after the addition of 30.0 mL of NaOH.

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 a buffer solution that is 0.255 mol L^-1 in hypochlorous acid (HClO)and 0.333 mol L^-1 in sodium hypochlorite (NaClO)? The K_a of hypochlorous acid is 3.8 × 10^-8.

Calculate the pH of a solution that is 0.295 mol L^-1 in sodium formate (HCOONa)and 0.205 mol L^-1 in formic acid (HCOOH). The K_a of formic acid is 1.77 × 10^-4.

A 1.00 L buffer solution is 0.150 mol L^-1 in C₆H₅COOH and 0.250 mol L^-1 in C₆H₅COOLi. Calculate the pH of the solution after the addition of 100.0 mL of 1.00 mol L^-1 HCl. The K_a for HC₇H₅O₂ is 6.5 × 10^-5.

Formic acid (HCOOH, K_a = 1.8 × 10^-4)is the principal component in the venom of stinging ants. What is the molarity of a formic acid solution if 25.00 mL of the formic acid solution requires 29.80 mL of 0.0567 mol L^-1 NaOH to reach the equivalence point?

A 100.0 mL sample of 0.10 mol L^-1 Ca(OH)₂ is titrated with 0.10 mol L^-1 HBr. Determine the pH of the solution after the addition of 300.0 mL HBr.

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.

What is the molar solubility of barium fluoride (BaF₂)in water? The solubility-product constant for BaF₂ is 1.7 × 10^-6 at 25 °C.

A 100.0 mL sample of 0.20 mol L^-1 HF is titrated with 0.10 mol L^-1 KOH. Determine the pH of the solution after the addition of 100.0 mL of KOH. The K_a of HF is 3.5 × 10^-4.

A 100.0 mL sample of 0.10 mol L^-1 NH₃ is titrated with 0.10 mol L^-1 HNO₃. Determine the pH of the solution after the addition of 150.0 mL of HNO₃. The K_b of NH₃ is 1.8 × 10^-5.