Chapter 18

Write balanced equations for the reactions between the following. a. aluminum and sulfuric acid b. calcium carbonate and hydrobromic acid

Identify the conjugate acid-base pairs in each reaction. a. \(\mathrm{NH}_{4}+(\mathrm{aq})+\mathrm{OH}^{-}(\mathrm{aq}) \rightleftharpoons \mathrm{NH}_{3}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l})\) b. \(\mathrm{HBr}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(\mathrm{aq})+\mathrm{Br}^{-}(\mathrm{aq})\) c. \(C O_{3}^{2-}(a q)+H_{2} O(1) \rightleftharpoons H C O_{3}^{-}(a q)+O H^{-}(a q)\)

Challenge The products of an acid-base reaction are \(\mathrm{H}_{3} \mathrm{O}^{+}\) and \(\mathrm{SO}_{4}^{2-} .\) Write a balanced equation for the reaction and identify the conjugate acid-base pairs.

A Explain why many Lewis acids and bases are not classified as Arrhenius or Brønsted-Lowry acids and base.

Compare the physical and chemical properties of acids and base

Explain how the concentrations of hydrogen ions and hydroxide ions determine whether a solution is acidic, basic, or neutral.

Explain why many compounds that contain one or more hydrogen atoms are not classified as Arrhenius acid.

Identify the conjugate acid-base pairs in the following equation. \(\mathrm{HNO}_{2}+\mathrm{H}_{2} \mathrm{O} \rightleftharpoons \mathrm{NO}_{2}^{-}+\mathrm{H}_{3} 0^{+}\)

Write the Lewis structure for phosphorus trichoride \((\mathrm{PC} / 3) .\) Is \(\mathrm{PCl}_{3}\) a lewis acid, a Lewis base, or neither?

Write ionization equations and acid ionization constant expressions for a. \(\mathrm{HClO}_{2} \quad\) b. HNO_ \(_{2} \quad\) c. HIOeach acid.

Write the first and second ionization equations for \(\mathrm{H}_{2} \mathrm{SeO}_{3}\)

Given the expression \(K_{\mathrm{a}}=\frac{\left[\mathrm{AsO}_{4}^{3-}\right]\left[\mathrm{H}_{3} \mathrm{O}^{+}\right]}{[\mathrm{HCN}]},\) write the balanced equation for the corresponding reaction.

Write ionization equations and base ionization constant expressions for the following bases. a. hexylamine \(\left(\mathrm{C}_{6} \mathrm{H}_{13} \mathrm{NH}_{2}\right)\) b. propylamine \(\left(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{NH}_{2}\right)\) c. carbonate ion \(\left(\mathrm{CO}_{3}^{2-}\right)\) d. hydrogen sulfite ion \(\left(\mathrm{HSO}_{3}^{-}\right)\)

Challenge Write an equation for a base equilibrium in which the base in the forward reaction is \(\mathrm{PO}_{4}^{3-}\) and the base in the reverse reaction is \(\mathrm{OH}^{-} .\)

Relate the strength of a weak acid to the strength of its conjugate base.

Identify the conjugate acid-base pairs in each equation. a. \(H C O O H(a q)+H_{2} O(1) \rightleftharpoons H C O O^{-}(a q)+H_{3} O^{+}(a q)\) b. \(\mathrm{NH}_{3}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightleftharpoons \mathrm{NH}_{4}+(\mathrm{aq})+\mathrm{OH}^{-}(\mathrm{aq})\)

Explain what the \(K_{\mathrm{b}}\) for aniline \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}\right)\) tells you \(\left(K_{\mathrm{b}}=4.3 \times 10^{-10}\right)\)

Challenge Calculate the number of \(\mathrm{H}^{+}\) ions and the number of \(\mathrm{OH}^{-}\) ions in 300 \(\mathrm{mL}\) of pure water at 298 \(\mathrm{K}\) .

Calculate the pH of solutions having the following ion concentrations at 298 \(\mathrm{K}\) . a. \(\left[\mathrm{H}^{+}\right]=1.0 \times 10^{-2} M \quad\) b. \(\left[\mathrm{H}^{+}\right]=3.0 \times 10^{-6} M\)

Calculate the pH of aqueous solutions with the following \([\mathrm{H}+]\) at 298 \(\mathrm{K}\) . a. \([\mathrm{H}+]=0.0055 \mathrm{M} \quad\) b. \([\mathrm{H}+]=0.000084 \mathrm{M}\)

Challenge Calculate the pH of a solution having \([0 \mathrm{H}-]=8.2 \times 10^{-6} \mathrm{M} .\)

Calculate the pH and pOH of aqueous solutions with the following concentrations at 298 \(\mathrm{K}\) . a. \(\left[\mathrm{OH}^{-}\right]=1.0 \times 10^{-6} M\) b. \(\left[\mathrm{OH}^{-}\right]=6.5 \times 10^{-4} M\) c. \(\left[\mathrm{H}^{+}\right]=3.6 \times 10^{-9} M\) d. \(\left[\mathrm{H}^{+}\right]=2.5 \times 10^{-2} \mathrm{M}\)

Calculate the pH and pOH of aqueous solutions with the following concentration at 298 \(\mathrm{K}\) . a. \(\left[\mathrm{OH}^{-}\right]=0.000033 M\) b. \(\left[\mathrm{H}^{+}\right]=0.0095 M\)

Challenge Calculate pH and pOH for an aqueous solution containing \(1.0 \times 10^{-3}\) mol of HCl dissolved in 5.0 \(\mathrm{L}\) of solution.

Calculate \(\left[\mathrm{H}^{+}\right]\) and \(\left[\mathrm{OH}^{-}\right]\) in each of the following solutions. \(\begin{array}{ll}{\text { a. Milk, } p H=6.50 .} & {\text { c. Milk of magnesia, } p H=10.50} \\ {\text { b. Lemon juice, pH }=2.37} & {\text { d. Household ammonia, } p H=11.90}\end{array}\)

Challenge Calculate the \(\left[\mathrm{H}^{+}\right]\) and \(\left[\mathrm{OH}^{-}\right]\) in a sample of seawater with a \(\mathrm{pOH}=5.60\)

Calculate the \(K_{\mathrm{a}}\) for the following acids using the given information. a. 0.220 \(\mathrm{M}\) solution of \(\mathrm{H}_{3} \mathrm{AsO}_{4}, \mathrm{pH}=1.50 \quad\) b. 0.0400 \(\mathrm{M}\) solution of \(\mathrm{HClO}_{2}, \mathrm{pH}=1.80\)

Calculate the \(K_{\mathrm{a}}\) of the following acids using the given information. a. 0.00330 \(\mathrm{M}\) solution of benzoic acid \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}\right), \mathrm{pOH}=10.70\) b. 0.100 \(\mathrm{M}\) solution of cyanic acid \((\mathrm{HCNO}), \mathrm{pOH}=11.00\) c. 0.150 \(\mathrm{M}\) solution of butanoic acid \(\left(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{COOH}\right), \mathrm{pOH}=11.18\)

A Explain why the pH of an acidic solution is always a smaller number than the pOH of the same solutio

Describe how you can determine the pH of a solution if you know its poH.

Explain the significance of \(K_{\mathrm{w}}\) in aqueous solutions.

Explain, using Le Châtelier's principle, what happens to the \(\left[\mathrm{H}^{+}\right]\) of a 0.10 \(\mathrm{M}\) solution of acetic acid when a drop of NaOH solution is added.

List the information needed to calculate the \(K_{\mathrm{a}}\) of a weak acid.

Calculate The pH of a tomato is approximately \(4.50 .\) What are \(\left[\mathrm{H}^{+}\right]\) and \(\left[\mathrm{OH}^{-}\right]\) in a tomato?

Determine the pH of a solution that contains \(1.0 \times 10^{-9} \mathrm{mol}\) of \(\mathrm{OH}^{-\mathrm{i} \text { ions }}\) per liter.

Calculate the pH of the following solutions. \(\begin{array}{ll}{\text { a. } 1.0 \mathrm{MHI}} & {\text { c. } 1.0 \mathrm{MKOH}} \\ {\text { b. } 0.050 \mathrm{MHNO}_{3}} & {\text { d. } 2.4 \times 10^{-5} \mathrm{MMg}(\mathrm{OH})_{2}}\end{array}\)

What is the molarity of a nitric acid solution if 43.33 \(\mathrm{mL}\) of 0.1000 \(\mathrm{M} \mathrm{KOH}\) solution is needed to neutralize 20.00 \(\mathrm{mL}\) of the acid solution?

What is the concentration of a household ammonia cleaning solution if 49.90 \(\mathrm{mL}\) of 0.5900 \(\mathrm{M} \mathrm{HCl}\) is required to neutralize 25.00 \(\mathrm{mL}\) of the solution?

Challenge How many milliliters of 0.500 \(\mathrm{M}\) NaOH would neutralize 25.00 \(\mathrm{mL}\) of 0.100 \(\mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4} ?\)

Write equations for the salt hydrolysis reactions occuring when the following salts dissolve in water. Classify each as acidic, basic, or neutral. a. ammonium nitrate c. rubidium acetate b. potassium sulfate d. calcium carbonate

Challenge Write the equation for the reaction that occurs in a titration of ammonium hydroxide (NH \(_{4} \mathrm{OH}\) ) with hydrogen bromide \((\mathrm{HBr}) .\) Will the \(\mathrm{pH}\) at the equivalence point be greater or less than 7\(?\)

Explain the difference between the equivalence point and the end point of a titration.

Compare the results of two experiments: First, a small amount of base is added to an unbuffered solution with a pH of 7. Second, the same amount of base is added to a buffered solution with a pH of 7.

Calculate the molarity of a solution of hydrobromic acid \((\mathrm{HBr})\) if 30.35 \(\mathrm{mL}\) of 0.1000 \(\mathrm{M}\) NaOH is required to titrate 25.00 \(\mathrm{mL}\) of the acid to the equivalence point.

Design an Experiment Describe how you would design and perform a titration in which you use 0.250 \(\mathrm{M} \mathrm{HNO}_{3}\) to determine the molarity of a cesium hydroxide solution. Include the formula and net ionic equations.

In terms of ion concentrations, distinguish between acidic, neutral, and basic solutions.

Write a balanced chemical equation that represents the self-ionization of water.

Classify each compound as an Arrhenius acid or an Arrhenius base. \(\begin{array}{ll}{\text { a. } \mathrm{Henius}} & {\text { c. } \mathrm{Mg}(\mathrm{OH})_{2}} \\ {\text { b. RboH }} & {\text { d. } \mathrm{Hg} \mathrm{PO}_{4}}\end{array}\)

Geology When a geologist adds a few drops of HCl to a rock, gas bubbles form. What might the geologist conclude about the nature of the gas and the rock?

Explain the difference between a monoprotic acid, a diprotic acid, and a triprotic acid. Give an example of each.