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Problem 88c
Predict the stronger acid in each pair: (c) HBrO3 or HBrO2
Problem 88e
Predict the stronger acid in each pair: (e) benzoic acid (C6H5COOH) or phenol (C6H5OH).
- Based on their compositions and structures and on conjugate acid–base relationships, select the stronger base in each of the following pairs: (a) BrO- or ClO- (c) HPO42- or H2PO4-
Problem 89
Problem 89b
Based on their compositions and structures and on conjugate acid–base relationships, select the stronger base in each of the following pairs: (b) BrO- or BrO2-
Problem 90b
Based on their compositions and structures and on conjugate acid–base relationships, select the stronger base in each of the following pairs: (b) PO43- or AsO43-
Problem 91c
Indicate whether each of the following statements is true or false. For each statement that is false, correct the statement to make it true. (a) In general, the acidity of binary acids increases from left to right in a given row of the periodic table. (b) In a series of acids that have the same central atom, acid strength increases with the number of hydrogen atoms bonded to the central atom. (c) Hydrotelluric acid 1H2Te2 is a stronger acid than H2S because Te is more electronegative than S.
Problem 92
Indicate whether each of the following statements is true or false. For each statement that is false, correct the statement to make it true. (a) Acid strength in a series of H¬A molecules increases with increasing size of A. (b) For acids of the same general structure but differing electronegativities of the central atoms, acid strength decreases with increasing electronegativity of the central atom. (c) The strongest acid known is HF because fluorine is the most electronegative element.
- Ammonia, NH3, acts as an Arrhenius base, a Brønsted-Lowry base, and a Lewis base, in aqueous solution. Write out the reaction NH3 undergoes with water and explain what properties of ammonia correspond to each of the three definitions of “base.”
Problem 93
- The fluoride ion reacts with water to produce HF. (c) Is fluoride acting as a Lewis acid or as a Lewis base when reacting with water?
Problem 94
Problem 95
Identify the Lewis acid and Lewis base among the reactants in each of the following reactions:
(a) Fe(ClO4)3(s) + 6 H2O(l) ⇌ [Fe(H2O)6]3+(aq) + 3 ClO4-(aq)
(b) CN-(aq) + H2O(l) ⇌ HCN(aq) + OH-(aq)
(c) (CH3)3N(g) + BF3(g) ⇌ (CH3)NBF3(s)
(d) HIO(lq) + NH2-(lq) ⇌ NH3(lq) + IO-(lq) (lq denotes liquid ammonia as solvent)
Problem 96
Identify the Lewis acid and Lewis base in each of the following reactions:
(a) HNO2(aq) + OH-(aq) ⇌ NO2-(aq) + H2O(l)
(b) FeBr3(s) + Br-(aq) ⇌ FeBr4-(aq)
(c) Zn2+(aq) + 4 NH3(aq) ⇌ Zn(NH3)42+(aq)
(d) SO2(g) + H2O(l) ⇌ H2SO3(aq)
- Predict which member of each pair produces the more acidic aqueous solution: (a) K+ or Cu2+ (b) Fe2+ or Fe3+ (c) Al3+ or Ga3+.
Problem 97
Problem 98
Which member of each pair produces the more acidic aqueous solution: (a) ZnBr2 or CdCl2 (b) CuCl or Cu(NO3)2 (c) Ca(NO3)2 or NiBr2
- Indicate whether each of the following statements is correct or incorrect. (e) The percent ionization of a weak acid in water increases as the concentration of the acid decreases.
Problem 99
Problem 99c
Indicate whether each of the following statements is correct or incorrect. (c) Conjugate acids of weak bases produce more acidic solutions than conjugate acids of strong bases.
Problem 99d
Indicate whether each of the following statements is correct or incorrect. (d) K+ ion is acidic in water because it causes hydrating water molecules to become more acidic.
Problem 100
A solution is made by adding 0.300 g Ca1OH221s2, 50.0 mL of 1.40 M HNO3, and enough water to make a final volume of 75.0 mL. Assuming that all of the solid dissolves, what is the pH of the final solution?
- Salts containing the phosphate ion are added to municipal water supplies to prevent the corrosion of lead pipes. (a) Based on the pKa values for phosphoric acid 1pKa1 = 7.5 * 10 - 3, pKa2 = 6.2 * 10 - 8, pKa3 = 4.2 * 10 - 132 what is the Kb value for the PO43 - ion?
Problem 101
Problem 102
Which, if any, of the following statements are true? (a) The stronger the base, the smaller the pKb. (b) The stronger the base, the larger the pKb. (c) The stronger the base, the smaller the Kb. (d) The stronger the base, the larger the Kb. (e) The stronger the base, the smaller the pKa of its conjugate acid. (f) The stronger the base, the larger the pKa of its conjugate acid.
Problem 103b
Predict how each molecule or ion would act, in the Brønsted-Lowry sense, in aqueous solution by writing 'acid,' 'base,' 'both,' or 'neither' on the line provided. (b) Prozac
Problem 104
Calculate the pH of a solution made by adding 2.50 g of lithium oxide 1Li2O2 to enough water to make 1.500 L of solution.
- What is the pH of a solution that is 2.5 * 10^-9 M in NaOH? Does your answer make sense? What assumption do we normally make that is not valid in this case?
Problem 106
- Oxalic acid H2C2O4 is a diprotic acid. By using data in Appendix D as needed, determine whether each of the following statements is true: (a) H2C2O4 can serve as both a Brønsted–Lowry acid and a Brønsted–Lowry base. (b) C2O4²⁻ is the conjugate base of HC2O4⁻. (c) An aqueous solution of the strong electrolyte KHC2O4 will have a pH of 6 or 7.
Problem 107
- Succinic acid (H2C4H6O4), which we will denote H2Suc, is a biologically relevant diprotic acid with the structure shown below. At 25 °C, the acid-dissociation constants for succinic acid are Ka1 = 6.9 * 10^-5 and Ka2 = 2.5 * 10^-6. (a) Determine the pH of a 0.32 M solution of H2Suc at 25 °C, assuming that only the first dissociation is relevant. (b) Determine the molar concentration of Suc2- in the solution in part (a). (c) Is the assumption you made in part (a) justified by the result from part (b)?
Problem 108
Problem 109a
Butyric acid is responsible for the foul smell of rancid butter. The pKa of butyric acid is 4.84. (a) Calculate the pKb for the butyrate ion.
Problem 109b
Butyric acid is responsible for the foul smell of rancid butter. The pKa of butyric acid is 4.84. (b) Calculate the pH of a 0.050 M solution of butyric acid.
Problem 109c
Butyric acid is responsible for the foul smell of rancid butter. The pKa of butyric acid is 4.84. (c) Calculate the pH of a 0.050 M solution of sodium butyrate.
Problem 110
Arrange the following 0.10 M solutions in order of increasing acidity: (i) NH4NO3, (ii) NaNO3, (iii) CH3COONH4, (iv) NaF, (v) CH3COONa.
- Ritalin is the trade name of a drug, methylphenidate, used to treat attention-deficit/hyperactivity disorder in young adults. The chemical structure of methylphenidate is
Problem 111
(a) Is Ritalin an acid or a base? An electrolyte or a nonelectrolyte?
Problem 112
The following observations are made about a diprotic acid H2A: (i) A 0.10 M solution of H2A has pH = 3.30. (ii) A 0.10 M solution of the salt NaHA is acidic. Which of the following could be the value of pKa2 for H2A: (i) 3.22, (ii) 5.30, (iii) 7.47, or (iv) 9.82?