CHM112 chapter 19 (all answered)

One type of acid-base buffer is composed of a weak , which will react with any added base, and its conjugate , which will react with any added acid. correct answers Blank 1: acid Blank 2: base Which of the following combinations could be used in an acid-base buffer system? Select all that apply. correct answers NH3 /NH4Cl CH3COOH/NaCH3COO HNO2 /KNO2 If NaClO (aq) is added to the reaction shown below, which of the following statements would be true? Select all that apply. HClO (aq) + H2O (l) ⇌ ClO- (aq) + H3O+ (aq) correct answers The pH of the solution would increase. The concentration of HClO (aq) would increase. Consider the dissociation of the weak acid HClO2, which can be represented by the balanced equation HClO2 (aq) + H2O (l) ⇌ ClO2- (aq) + H3O+ (aq). Which of the following options correctly describe the effect of adding solid KClO2 to this system? Select all that apply. correct answers The solution pH will increase. The % dissociation of HClO2 will decrease. Which of the following statements correctly reflect the relationship between buffer composition and solution pH given that Ka = [H3O+][A−][HA][H3O+][A-][HA]? Select all that apply. correct answers The pH of the solution depends on the ratio [HA][A−][HA][A-]. If the relative amount of HA is increased, the solution pH will decrease. Which of the following options correctly describes the function of an acid-base buffer? correct answers A buffer minimizes changes in pH when acid or base is added to the solution. Strong acid has been added. Strong base has been added. correct answers A B Which of the following can NOT be used as an acid-base buffer solution? Select all that apply. correct answers 0.5 M HNO3 and 0.5 M NaNO3 0.3 M HCl and 0.3 M NaOH Consider the equilibrium system NH3 (aq) + H2O (l) ⇌ NH4+ (aq) + OH- (aq). If some solid NH4Cl were added to the system, the equilibrium would shift to the _____ and the [OH-] would _____. correct answers left; decrease In a 0.75 M HF solution, the HF is 2.2% dissociated. When NaF (s) is added to this solution the percent dissociation of HF _____ and the pH of the resulting solution will be _____ than its