The pKa of 2-chloropropanoic acid, CH3CHClCO2H, is 2.83. Calculate the Gibbs energy for the dissociation CH3CHClCO2H(aq) + H2O(aq) ⇌ CH3CHClCO2-(aq) + H3O+(aq) At a temperature of 298 K.

A) +16.1 kJ mol-1 B) +7.01 kJ mol-1 C) +3.05 kJ mol-1 D) +496 J mol-1 A) +16.1 kJ mol-1 B) +7.01 kJ mol-1 C) +3.05 kJ mol-1 D) +496 J mol-1 A

One drop, 0.200 cm3, of 1.00 mol dm-3 of aqueous sodium hydroxide, NaOH, solution, is added to 25.0 cm3 of a phosphate buffer that is 0.040 mol dm-3 in KH2PO4(aq) and 0.020 mol dm−3 in K2HPO4(aq). Calculate the resulting pH of the solution given that the second acid dissociation constant, pKa2, for phosphoric acid is 7.21.

A) 7.21 B) 6.91 C) 7.16 D) 7.27 A) 7.21 B) 6.91 C) 7.16 D) 7.27 D

Calculate the pH of a solution produced by mixing 4.3 cm3 of 0.100 mol dm-3 potassium hydroxide, KOH, solution to 50.0 cm3 of 0.136 mol dm-3 propanoic acid, C2H5COOH, solution. The pKa of propanoic acid is 4.87.

A) 1.93 B) 2.44 C) 3.67 D) 2.16 A) 1.93 B) 2.44 C) 3.67 D) 2.16 C

Calculate the pH of an aqueous solution of sodium hydrogenphosphite, NaHPO3. For phosphorous acid, H2PO3, pKa1 = 2.00 and pKa2 = 6.59.

A) 4.30 B) 2.00 C) 6.59 D) 2.29 A) 4.30 B) 2.00 C) 6.59 D) 2.29

The molar conductivity of a 0.010 mol dm-3 solution of propanoic acid, C2H5COOH, has been measured to be 2.25 mS m2 mol-1 at 298 K. The ionic conductivity of hydronium, H3O+, ions is 34.96 mS m2 mol-1 and of propanoate, C2H5COO-, ions is 26.3 mS m2 mol-1 at this temperature. Determine the acid dissociation constant of propanoic acid at 298 K.

A) 2.88 F1F1F1S1F1F1F10 10-8 B) 3.67 F1F1F1S1F1F1F10 10-4 C) 1.91 F1F1F1S1F1F1F10 10-3 D) 1.35 F1F1F1S1F1F1F10 10-5 A) 2.88 F1F1F1S1F1F1F10 10-8 B) 3.67 F1F1F1S1F1F1F10 10-4 C) 1.91 F1F1F1S1F1F1F10 10-3 D) 1.35 F1F1F1S1F1F1F10 10-5

Use the Debye-Hückel limiting law to determine the mean activity coefficient for the Ca2+ and NO3- ions in a 0.005 mol dm-3 aqueous solution of calcium nitrate, Ca(NO3)2.

A) 0.94 B) 0.97 C) 0.75 D) 0.12 A) 0.94 B) 0.97 C) 0.75 D) 0.12

Calculate the limiting molar conductivity of sodium chloride, NaCl, from the following measurements of molar conductivity at various concentrations. The data refer to a temperature of 298 K. \(\begin{array}{lcccc} c / \mathrm{mol} \mathrm{dm}^{-3} & 0.010 & 0.020 & 0.050 & 0.100 \\ \Lambda_{\mathrm{m}} / \mathrm{S} \mathrm{m}{ }^{-1}\left(\mathrm{~mol} \mathrm{dm}^{-3}\right)^{-1} & 117.45 & 115.70 & 111.01 & 106.69 \end{array}\)

A) 122.6 S m-1 (mol dm-3)-1 B) 106.9 S m-1 (mol dm-3) C) 119.3 S m-1 (mol dm-3)-1 D) 96.3 S m-1 (mol dm-3)-1 A) 122.6 S m-1 (mol dm-3)-1 B) 106.9 S m-1 (mol dm-3) C) 119.3 S m-1 (mol dm-3)-1 D) 96.3 S m-1 (mol dm-3)-1

The mobility of a tetramethylammonium, [N(CH3)4]+, ion in dilute aqueous solution is 4.65 F1F1F1S1F1F1F10 10−8 m2 s−1 V−1 at a temperature of 298 K. Estimate the radius of the ion, given that the viscosity of water at this temperature is 1.00 mN s m-2.

A) 1.2 Å B) 2.4 Å C) 1.6 Å D) 1.8 Å A) 1.2 Å B) 2.4 Å C) 1.6 Å D) 1.8 Å

The pKb of the base cyclohexamine, C6H11NH2, is 3.36. What is the pKa of the conjugate acid, C6H11NH3+?

A) 3.36 B) 14.00 C) 10.64 D) 7.64 A) 3.36 B) 14.00 C) 10.64 D) 7.64

Calculate the concentration of hydronium, H3O+, ions in a solution of pH = 11.2.

A) 11.2 F1F1F1S1F1F1F10 10-3 mol dm-3 B) 1.36 F1F1F1S1F1F1F10 10-5 mol dm-3 C) 1.58 F1F1F1S1F1F1F10 1010 mol dm-3 D) 6.3 F1F1F1S1F1F1F10 10-12 mol dm-3 A) 11.2 F1F1F1S1F1F1F10 10-3 mol dm-3 B) 1.36 F1F1F1S1F1F1F10 10-5 mol dm-3 C) 1.58 F1F1F1S1F1F1F10 1010 mol dm-3 D) 6.3 F1F1F1S1F1F1F10 10-12 mol dm-3

The equilibrium constant for the reaction H2(g) + Br2(g) ∏ 2 HBr(g) Is 2.1 F1F1F1S1F1F1F10 109 at 298 K. What is the value of the equilibrium constant for the reaction ½ H2(g) + ½ Br2(g) ∏ HBr(g) at this temperature?

A) 2.1 F1F1F1S1F1F1F10 109 B) 4.4 F1F1F1S1F1F1F10 1018 C) 1.0 F1F1F1S1F1F1F10 109 D) 46 F1F1F1S1F1F1F10 103 A) 2.1 F1F1F1S1F1F1F10 109 B) 4.4 F1F1F1S1F1F1F10 1018 C) 1.0 F1F1F1S1F1F1F10 109 D) 46 F1F1F1S1F1F1F10 103

Exam 5: Chemical Change

The pK_a of 2-chloropropanoic acid, CH₃CHClCO₂H, is 2.83. Calculate the Gibbs energy for the dissociation CH₃CHClCO₂H(aq) + H₂O(aq) ⇌ CH₃CHClCO₂^-(aq) + H₃O⁺(aq) At a temperature of 298 K.

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Question 1

Correct Answer:

Verified

One drop, 0.200 cm³, of 1.00 mol dm^-3 of aqueous sodium hydroxide, NaOH, solution, is added to 25.0 cm³ of a phosphate buffer that is 0.040 mol dm^-3 in KH₂PO₄(aq) and 0.020 mol dm⁻³ in K₂HPO₄(aq). Calculate the resulting pH of the solution given that the second acid dissociation constant, pK_a2, for phosphoric acid is 7.21.

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Question 2

Correct Answer:

Verified

Calculate the pH of a solution produced by mixing 4.3 cm³ of 0.100 mol dm^-3 potassium hydroxide, KOH, solution to 50.0 cm³ of 0.136 mol dm^-3 propanoic acid, C₂H₅COOH, solution. The pK_a of propanoic acid is 4.87.

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Question 3

Correct Answer:

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Calculate the pH of an aqueous solution of sodium hydrogenphosphite, NaHPO₃. For phosphorous acid, H₂PO₃, pK_a1 = 2.00 and pK_a2 = 6.59.

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Question 4

The concentration of OH^- ions in a solution is 5.62 mmol dm^-3. Determine the pH of the solution.

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Question 5

The molar conductivity of a 0.010 mol dm^-3 solution of propanoic acid, C₂H₅COOH, has been measured to be 2.25 mS m² mol^-¹ at 298 K. The ionic conductivity of hydronium, H₃O⁺, ions is 34.96 mS m² mol^-¹and of propanoate, C₂H₅COO^-, ions is 26.3 mS m² mol^-¹ at this temperature. Determine the acid dissociation constant of propanoic acid at 298 K.

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Question 6

Use the Debye^-Hückel limiting law to determine the mean activity coefficient for the Ca²⁺ and NO₃^- ions in a 0.005 mol dm^-3 aqueous solution of calcium nitrate, Ca(NO₃)₂.

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Question 7

Calculate the limiting molar conductivity of sodium chloride, NaCl, from the following measurements of molar conductivity at various concentrations. The data refer to a temperature of 298 K. c/ 0.010 0.020 0.050 0.100 / 117.45 115.70 111.01 106.69

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Question 8

The standard potential for the cell Cl₂(g) + Cu(s) ⇌ CuCl₂(aq) Is +1.02 V. Determine the potential of the cell at a temperature of 298 K when the partial pressure of chlorine, Cl₂, gas is 0.100 bar and the concentration of copper (II) chloride, CuCl₂, is 0.017 mol dm^-3.

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Question 9

The value of the equilibrium constant for the reaction C₂H₄(g) + H₂O(g) ∏ C₂H₅OH(g) Is 9.920 at 423 K and 6.397 at 523 K. Determine the average value of the standard enthalpy of reaction over this temperature range.

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Question 10

The standard cell potential for the Daniell cell Zn(s)|ZnSO₄(aq)||CuSO₄(aq)|Cu(s) Is +1.102 V. Determine the cell potential at a temperature of 25°C if the concentration of zinc sulfate, ZnSO₄, is 0.050 mol dm^-3 and the concentration of copper sulfate, CuSO₄, is 0.200 mol dm^-3.

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Question 11

When phosphorus pentachloride, PCl₅, is heated at a constant pressure of exactly 1 bar to a temperature of 1400 K, the amount of phosphorus pentachloride decreases by 20.7% because of dissociation to phosphorus trichloride, PCl₃, and chlorine, Cl₂. Determine the equilibrium constant at this temperature.

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Question 12

The mobility of a tetramethylammonium, [N(CH₃)₄]⁺, ion in dilute aqueous solution is 4.65  10⁻⁸ m² s⁻¹ V⁻¹ at a temperature of 298 K. Estimate the radius of the ion, given that the viscosity of water at this temperature is 1.00 mN s m^-2.

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Question 13

Estimate the solubility of copper (I) chloride, CuCl, in a 0.10 mol dm^-3 solution of sodium chloride, NaCl, at a temperature of 298 K. The solubility of copper (I) chloride in water is 1.0  10^-3 mol dm^-3 at this temperature.

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Question 14

The standard cell potential for the fuel cell 2H₂(g) + O₂(g) ⇌ 2 H₂O(l) Is E^o_cell = +1.23 V at a temperature of 298 K and +1.18 V at 358 K. Estimate the standard entropy of the cell reaction.

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Question 15

The pK_b of the base cyclohexamine, C₆H₁₁NH₂, is 3.36. What is the pK_a of the conjugate acid, C₆H₁₁NH₃⁺?

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Question 16

Calculate the concentration of hydronium, H₃O⁺, ions in a solution of pH = 11.2.

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Question 17

The equilibrium constant for the reaction H₂(g) + Br₂(g) ∏ 2 HBr(g) Is 2.1  10⁹ at 298 K. What is the value of the equilibrium constant for the reaction ½ H₂(g) + ½ Br₂(g) ∏ HBr(g) at this temperature?

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Question 18

For sulfur hexafluoride, SF₆, the standard Gibbs energy of formation of is -992 kJ mol^-1 and the standard entropy of formation is -350 J K^-1 mol^-1 at 298 K. Assuming that the values of the enthalpy and entropy of formation vary little with temperature, estimate the standard Gibbs energy of formation of sulfur hexafluoride at 348 K.

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Question 19

The standard Gibbs energy of reaction for the thermal decomposition of ammonium chloride, NH₄Cl NH₄Cl(s) ∏ NH₃(g) + HCl(g) Is +35.0 kJ mol^-1 at 225 °C. Calculate the partial pressure of ammonia, NH₃, gas produced when ammonium chloride is allowed to decompose at a pressure of 1 bar at this temperature.

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Question 20

Showing 1 - 20 of 30

The pK_a of 2-chloropropanoic acid, CH₃CHClCO₂H, is 2.83. Calculate the Gibbs energy for the dissociation CH₃CHClCO₂H(aq) + H₂O(aq) ⇌ CH₃CHClCO₂^-(aq) + H₃O⁺(aq) At a temperature of 298 K.

Calculate the pH of a solution produced by mixing 4.3 cm³ of 0.100 mol dm^-3 potassium hydroxide, KOH, solution to 50.0 cm³ of 0.136 mol dm^-3 propanoic acid, C₂H₅COOH, solution. The pK_a of propanoic acid is 4.87.

Calculate the pH of an aqueous solution of sodium hydrogenphosphite, NaHPO₃. For phosphorous acid, H₂PO₃, pK_a1 = 2.00 and pK_a2 = 6.59.

The concentration of OH^- ions in a solution is 5.62 mmol dm^-3. Determine the pH of the solution.

Use the Debye^-Hückel limiting law to determine the mean activity coefficient for the Ca²⁺ and NO₃^- ions in a 0.005 mol dm^-3 aqueous solution of calcium nitrate, Ca(NO₃)₂.

Calculate the limiting molar conductivity of sodium chloride, NaCl, from the following measurements of molar conductivity at various concentrations. The data refer to a temperature of 298 K. c/ 0.010 0.020 0.050 0.100 / 117.45 115.70 111.01 106.69

The standard potential for the cell Cl₂(g) + Cu(s) ⇌ CuCl₂(aq) Is +1.02 V. Determine the potential of the cell at a temperature of 298 K when the partial pressure of chlorine, Cl₂, gas is 0.100 bar and the concentration of copper (II) chloride, CuCl₂, is 0.017 mol dm^-3.

The value of the equilibrium constant for the reaction C₂H₄(g) + H₂O(g) ∏ C₂H₅OH(g) Is 9.920 at 423 K and 6.397 at 523 K. Determine the average value of the standard enthalpy of reaction over this temperature range.

The standard cell potential for the Daniell cell Zn(s)|ZnSO₄(aq)||CuSO₄(aq)|Cu(s) Is +1.102 V. Determine the cell potential at a temperature of 25°C if the concentration of zinc sulfate, ZnSO₄, is 0.050 mol dm^-3 and the concentration of copper sulfate, CuSO₄, is 0.200 mol dm^-3.

The mobility of a tetramethylammonium, [N(CH₃)₄]⁺, ion in dilute aqueous solution is 4.65  10⁻⁸ m² s⁻¹ V⁻¹ at a temperature of 298 K. Estimate the radius of the ion, given that the viscosity of water at this temperature is 1.00 mN s m^-2.

Estimate the solubility of copper (I) chloride, CuCl, in a 0.10 mol dm^-3 solution of sodium chloride, NaCl, at a temperature of 298 K. The solubility of copper (I) chloride in water is 1.0  10^-3 mol dm^-3 at this temperature.

The standard cell potential for the fuel cell 2H₂(g) + O₂(g) ⇌ 2 H₂O(l) Is E^o_cell = +1.23 V at a temperature of 298 K and +1.18 V at 358 K. Estimate the standard entropy of the cell reaction.

The pK_b of the base cyclohexamine, C₆H₁₁NH₂, is 3.36. What is the pK_a of the conjugate acid, C₆H₁₁NH₃⁺?

Calculate the concentration of hydronium, H₃O⁺, ions in a solution of pH = 11.2.

The equilibrium constant for the reaction H₂(g) + Br₂(g) ∏ 2 HBr(g) Is 2.1  10⁹ at 298 K. What is the value of the equilibrium constant for the reaction ½ H₂(g) + ½ Br₂(g) ∏ HBr(g) at this temperature?

The Propertiesof Gases

The First Law of Thermodynamics

The Second Law of Thermodynamics

Physical Transformations

Chemical Kinetics

Quantum Theory

Atomic Structure

The Chemical Bond

Molecular Interactions

Molecular Spectroscopy

Statistical Thermodynamics

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Exam 5: Chemical Change

The pKa of 2-chloropropanoic acid, CH3CHClCO2H, is 2.83. Calculate the Gibbs energy for the dissociation CH3CHClCO2H(aq) + H2O(aq) ⇌ CH3CHClCO2-(aq) + H3O+(aq) At a temperature of 298 K.

Calculate the pH of a solution produced by mixing 4.3 cm3 of 0.100 mol dm-3 potassium hydroxide, KOH, solution to 50.0 cm3 of 0.136 mol dm-3 propanoic acid, C2H5COOH, solution. The pKa of propanoic acid is 4.87.

Calculate the pH of an aqueous solution of sodium hydrogenphosphite, NaHPO3. For phosphorous acid, H2PO3, pKa1 = 2.00 and pKa2 = 6.59.

The concentration of OH- ions in a solution is 5.62 mmol dm-3. Determine the pH of the solution.

Use the Debye-Hückel limiting law to determine the mean activity coefficient for the Ca2+ and NO3- ions in a 0.005 mol dm-3 aqueous solution of calcium nitrate, Ca(NO3)2.

Calculate the limiting molar conductivity of sodium chloride, NaCl, from the following measurements of molar conductivity at various concentrations. The data refer to a temperature of 298 K. c/ 0.010 0.020 0.050 0.100 / 117.45 115.70 111.01 106.69

The standard potential for the cell Cl2(g) + Cu(s) ⇌ CuCl2(aq) Is +1.02 V. Determine the potential of the cell at a temperature of 298 K when the partial pressure of chlorine, Cl2, gas is 0.100 bar and the concentration of copper (II) chloride, CuCl2, is 0.017 mol dm-3.

The value of the equilibrium constant for the reaction C2H4(g) + H2O(g) ∏ C2H5OH(g) Is 9.920 at 423 K and 6.397 at 523 K. Determine the average value of the standard enthalpy of reaction over this temperature range.

The standard cell potential for the Daniell cell Zn(s)|ZnSO4(aq)||CuSO4(aq)|Cu(s) Is +1.102 V. Determine the cell potential at a temperature of 25°C if the concentration of zinc sulfate, ZnSO4, is 0.050 mol dm-3 and the concentration of copper sulfate, CuSO4, is 0.200 mol dm-3.

The mobility of a tetramethylammonium, [N(CH3)4]+, ion in dilute aqueous solution is 4.65  10−8 m2 s−1 V−1 at a temperature of 298 K. Estimate the radius of the ion, given that the viscosity of water at this temperature is 1.00 mN s m-2.

Estimate the solubility of copper (I) chloride, CuCl, in a 0.10 mol dm-3 solution of sodium chloride, NaCl, at a temperature of 298 K. The solubility of copper (I) chloride in water is 1.0  10-3 mol dm-3 at this temperature.

The standard cell potential for the fuel cell 2 H2(g) + O2(g) ⇌ 2 H2O(l) Is Eocell = +1.23 V at a temperature of 298 K and +1.18 V at 358 K. Estimate the standard entropy of the cell reaction.

The pKb of the base cyclohexamine, C6H11NH2, is 3.36. What is the pKa of the conjugate acid, C6H11NH3+?

Calculate the concentration of hydronium, H3O+, ions in a solution of pH = 11.2.

The equilibrium constant for the reaction H2(g) + Br2(g) ∏ 2 HBr(g) Is 2.1  109 at 298 K. What is the value of the equilibrium constant for the reaction ½ H2(g) + ½ Br2(g) ∏ HBr(g) at this temperature?

The Propertiesof Gases

The First Law of Thermodynamics

The Second Law of Thermodynamics

Physical Transformations

Chemical Kinetics

Quantum Theory

Atomic Structure

The Chemical Bond

Molecular Interactions

Molecular Spectroscopy

Statistical Thermodynamics

Filters

The pK_a of 2-chloropropanoic acid, CH₃CHClCO₂H, is 2.83. Calculate the Gibbs energy for the dissociation CH₃CHClCO₂H(aq) + H₂O(aq) ⇌ CH₃CHClCO₂^-(aq) + H₃O⁺(aq) At a temperature of 298 K.

Calculate the pH of a solution produced by mixing 4.3 cm³ of 0.100 mol dm^-3 potassium hydroxide, KOH, solution to 50.0 cm³ of 0.136 mol dm^-3 propanoic acid, C₂H₅COOH, solution. The pK_a of propanoic acid is 4.87.

Calculate the pH of an aqueous solution of sodium hydrogenphosphite, NaHPO₃. For phosphorous acid, H₂PO₃, pK_a1 = 2.00 and pK_a2 = 6.59.

The concentration of OH^- ions in a solution is 5.62 mmol dm^-3. Determine the pH of the solution.

Use the Debye^-Hückel limiting law to determine the mean activity coefficient for the Ca²⁺ and NO₃^- ions in a 0.005 mol dm^-3 aqueous solution of calcium nitrate, Ca(NO₃)₂.

The standard potential for the cell Cl₂(g) + Cu(s) ⇌ CuCl₂(aq) Is +1.02 V. Determine the potential of the cell at a temperature of 298 K when the partial pressure of chlorine, Cl₂, gas is 0.100 bar and the concentration of copper (II) chloride, CuCl₂, is 0.017 mol dm^-3.

The value of the equilibrium constant for the reaction C₂H₄(g) + H₂O(g) ∏ C₂H₅OH(g) Is 9.920 at 423 K and 6.397 at 523 K. Determine the average value of the standard enthalpy of reaction over this temperature range.

The standard cell potential for the Daniell cell Zn(s)|ZnSO₄(aq)||CuSO₄(aq)|Cu(s) Is +1.102 V. Determine the cell potential at a temperature of 25°C if the concentration of zinc sulfate, ZnSO₄, is 0.050 mol dm^-3 and the concentration of copper sulfate, CuSO₄, is 0.200 mol dm^-3.

The mobility of a tetramethylammonium, [N(CH₃)₄]⁺, ion in dilute aqueous solution is 4.65  10⁻⁸ m² s⁻¹ V⁻¹ at a temperature of 298 K. Estimate the radius of the ion, given that the viscosity of water at this temperature is 1.00 mN s m^-2.

Estimate the solubility of copper (I) chloride, CuCl, in a 0.10 mol dm^-3 solution of sodium chloride, NaCl, at a temperature of 298 K. The solubility of copper (I) chloride in water is 1.0  10^-3 mol dm^-3 at this temperature.

The standard cell potential for the fuel cell 2H₂(g) + O₂(g) ⇌ 2 H₂O(l) Is E^o_cell = +1.23 V at a temperature of 298 K and +1.18 V at 358 K. Estimate the standard entropy of the cell reaction.

The pK_b of the base cyclohexamine, C₆H₁₁NH₂, is 3.36. What is the pK_a of the conjugate acid, C₆H₁₁NH₃⁺?

Calculate the concentration of hydronium, H₃O⁺, ions in a solution of pH = 11.2.

The equilibrium constant for the reaction H₂(g) + Br₂(g) ∏ 2 HBr(g) Is 2.1  10⁹ at 298 K. What is the value of the equilibrium constant for the reaction ½ H₂(g) + ½ Br₂(g) ∏ HBr(g) at this temperature?