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Problem 3
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. (b) The pH of solution B is definitely greater than 7.00. (c) The pH of solution B is greater than that of solution A.
- Addition of phenolphthalein to an unknown colorless solution does not cause a color change. The addition of bromthymol blue to the same solution leads to a yellow color. (a) Is the solution acidic, neutral, or basic?
Problem 4
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?
- For each of these reactions, identify the acid and base among the reactants, and state if the acids and bases are Lewis, Arrhenius, and/or Brønsted–Lowry: (a) PCl4^+ + Cl^- → PCl5 (b) NH3 + BF3 → H3NBF3 (c) [Al(H2O)6]^3+ + H2O → [Al(H2O)5OH]^2+ + H3O^+
Problem 12
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?