Problem 32
Deuterium oxide 1D2O, where D is deuterium, the hydrogen-2 isotope) has an ion-product constant, Kw, of 8.9 * 10-16 at 20 °C. Calculate 3D+4 and 3OD-4 for pure (neutral) D2O at this temperature.
Problem 120
At 50 °C, the ion-product constant for H2O has the value Kw = 5.48 * 10-14. (a) What is the pH of pure water at 50 °C? (b) Based on the change in Kw with temperature, predict whether ΔH is positive, negative, or zero for the autoionization reaction of water: 2 H2O1l2 Δ H3O+1aq2 + OH-1aq2
Problem 3a
The indicator methyl orange has been added to both of the following solutions. Based on the colors, classify each statement as true or false: (a) The pH of solution A is definitely less than 7.00.
Problem 4b
The probe of the pH meter shown here is sitting in a beaker that contains a clear liquid. You are told the liquid is pure water, a solution of HCl(aq), or a solution of KOH(aq). (b) If the liquid is one of the solutions, what is its molarity?
Problem 4c
The probe of the pH meter shown here is sitting in a beaker that contains a clear liquid. (c) Why is the temperature given on the pH meter?
Problem 5a
The following diagrams represent aqueous solutions of three acids, HX, HY, and HZ. The water molecules have been omitted for clarity, and the hydrated proton is represented as H+ rather than H3O+. (a) Which of the acids is a strong acid? Explain.
Problem 5b
The following diagrams represent aqueous solutions of three acids, HX, HY, and HZ. The water molecules have been omitted for clarity, and the hydrated proton is represented as H+ rather than H3O+.(b) Which acid would have the smallest aciddissociation constant, Ka?
Problem 5c
The following diagrams represent aqueous solutions of three acids, HX, HY, and HZ. The water molecules have been omitted for clarity, and the hydrated proton is represented as H+ rather than H3O+.(c) Which solution would have the highest pH?
Problem 8
Each of the three molecules shown here contains an OH group, but one molecule acts as a base, one as an acid, and the third is neither acid nor base. (c) Which one is neither acidic nor basic?
Problem 9a
Phenylephrine, an organic substance with molecular formula C9H13NO2, is used as a nasal decongenstant in over-thecounter medications. The molecular structure of phenylephrine is shown below using the usual shortcut organic structure. (a) Would you expect a solution of phenylephrine to be acidic, neutral, or basic?
Problem 9c
Phenylephrine, an organic substance with molecular formula C9H13NO2, is used as a nasal decongenstant in over-thecounter medications. The molecular structure of phenylephrine is shown below using the usual shortcut organic structure. (c) Would you expect a solution of phenylephrine hydrochloride to be acidic, neutral, or basic?
Problem 11a
Consider the molecular models shown here, where X represents a halogen atom. (a) If X is the same atom in both molecules, which molecule will be more acidic?
Problem 11b
Consider the molecular models shown here, where X represents a halogen atom. (b) Does the acidity of each molecule increase or decrease as the electronegativity of the atom X increases?
Problem 13
NH31g2 and HCl(g) react to form the ionic solid NH4Cl1s2. Which substance is the Brønsted–Lowry acid in this reaction? Which is the Brønsted–Lowry base?
Problem 14
Which of the following statements is false? (a) An Arrhenius base increases the concentration of OH- in water. (b) A Brønsted-Lowry base is a proton acceptor. (c) Water can act as a Brønsted–Lowry acid. (d) Water can act as a Brønsted–Lowry base. (e) Any compound that contains an –OH group acts as a Brønsted-Lowry base.
Problem 15
Give the conjugate base of the following Brønsted–Lowry acids: (i) HIO3, (ii) NH4+.
Problem 16a
Give the conjugate base of the following Brønsted–Lowry acids: (i) HCOOH, (ii) HPO42-.
Problem 16b
Give the conjugate acid of the following Brønsted–Lowry bases: (i) SO42-, (ii) CH3NH2.
Problem 17b
Identify the Brønsted–Lowry acid and the Brønsted–Lowry base on the left side of each of the following equations, and also identify the conjugate acid and conjugate base of each on the right side: (b) 1CH323N1aq2 + H2O1l2Δ1CH323NH +1aq2 + OH -1aq2
Problem 18a
Identify the Brønsted–Lowry acid and the Brønsted– Lowry base on the left side of each equation, and also identify the conjugate acid and conjugate base of each on the right side. (a) HBrO1aq2 + H2O1l2ΔH3O+1aq2 + BrO-1aq2
Problem 19a
The hydrogen sulfite ion 1HSO3-2 is amphiprotic. Write a balanced chemical equation showing how it acts as an acid toward water and another equation showing how it acts as a base toward water.
Problem 19b
What is the conjugate acid of HSO3-? What is its conjugate base?
Problem 20a
Write an equation for the reaction in which H2C6H7O5-1aq2 acts as a base in H2O1l2.
Problem 20b
Write an equation for the reaction in which H2C6H7O5-1aq2 acts as an acid in H2O1l2.
Problem 21a
Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (a) CH3COO-
Problem 21b
Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (b) HCO3-
Problem 21c
Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (c) O2-
Problem 21d
Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (d) Cl-
Problem 21e
Label each of the following as being a strong base, a weak base, or a species with negligible basicity. In each case write the formula of its conjugate acid, and indicate whether the conjugate acid is a strong acid, a weak acid, or a species with negligible acidity: (e) NH3.
Problem 22
Label each of the following as being a strong acid, a weak acid, or a species with negligible acidity. In each case write the formula of its conjugate base, and indicate whether the conjugate base is a strong base, a weak base, or a species with negligible basicity: (a) HCOOH
Ch.16 - Acid-Base Equilibria
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