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Chemistry, General 9e (Petrucci) Chapter 17 Additional Aspects of Acid-Base Equilibria 1) The common ion in a mixture of a weak base and a strong base is the hydronium ion. Register to View Answer F Diff: Answer: 2 Refere nce: Sectio n 17 T True F Diff: 2hsoluti Reference: eon Section 17 chan 1 Tr pges H slight ly owith f addit ion of aa small bamou unt of f acid f or ebase. Register to View Answer F Diff: 2 and Reference: sits Section 17 t conju 2 A id r gate obase nwill gform a abuffe cr. Register to View Answer F Diff: Answer: 2 Refere nce: Sectio n 17 T True F Diff: 2hrange Reference: eof Section most 17.2 Tange cacidobase l indic oators r is 1 pH cunit. h Register to View Answer F Diff: Answer: 1 Refere nce: Sectio n 17 A True F Diff: 1nsoluti Reference:of on Section 17 t HCN 3 Ia h(aq) ewith NaO t H(aq) i , the t equiv r alenc ae t point i occur os at a npH great oer f than 7. Register to View Answer F Diff: 1oion, Reference: r the Section end 17.4 F titrat apoint nneed s to amatc ch the cequiv ualenc re apoint t. e Register to View Answer F Diff: 1 Reference: Section 17 4 A acid-strong base will produce a longer vertical section of a weak titration curve than will a strong acid-strong base. A n s w e r : True F Diff: Answer: 1 Refere nce: Sectio n 17 A True F Diff: 1 proti Reference: sc acid Section 17 asuch 5 A poly l as t NaH CO3 ocann f ot acid aas an acid. Register to View Answer F Diff: 1 Refere nce: Sectio n 17 H It will lower the pH. B) The pH will C) not change. The solution D) becomes hotter. The pH cannot be measured. E) It will raise the pH. Register to View AnswerDiff: 1 Reference: Section 17-1 14) How will addition of sodium chloride affect the pH of a HCl solution? A) It will lower B) the pH. The pH will C) not change. The solution D) becomes hotter. The pH cannot be measured. E) It will raise the pH. Register to View AnswerDiff: 1 Reference: Section 17-1 15) What is the [H3O+] of a solution measured to be 0.20 M in sodium acetate and 0.40 M in acetic acid? [Ka = 1.8 10-5] A) 1.8 10-5 B) 9.0 10-6 C) 3.6 10-5 D) 7.2 10-5 E) 4.7 Register to View AnswerDiff: 1 Reference: Section 17-1 16) What is the concentration of the acetate ion of a solution measured to be 0.20 M acetic acid and 0.20 M in hydrochloric acid? [Ka for acetic acid = 1.8 10-5] A) 3.6 10-5 B) 9.0 10-6 C) 1.8 10-5 D) 7.2 10-5 E) 0.20 Register to View AnswerDiff: 1 Reference: Section 17-1 17) Ten of 0.10 M NH3(aq) (K = 1.8 10-5) is mixed with 10 mL of 0.10 M NH4Cl. Neglecting the milliliters differences between activities and concentrations, the resulting solution: A) has a pH = B) 4.74 has a [H+] of C) approximately 10-3 M has a [NH4+] greater than that of the NH4Cl(aq) D) has an [OH-] E) of 1.8 10-5 M is acidic Register to View AnswerDiff: 1 Reference: Section 17-1 18) If some NH4Cl is added to an aqueous solution of NH3: A) the pH of the solution will increase B) the pH of the solution will decrease C) the solution D) will not have pH the pH of the solution will not change E) NH4Cl cannot be added to NH3 Register to View AnswerDiff: 1 Reference: Section 17-1 19) In 0.100 M HC2H3O2(aq), [H3O+(aq)] = [C2H3O2-(aq)] = 1.3 x 10-3 M. If a few drops of concentrated HCl(aq) are added to this solution, the C2H3O2-(aq) concentration is A) < 1.3 x 10-3 M. B) > 1.3 x 10-3 M. C) = 1.3 x 10-3 M. D) 0.100 M. Register to View AnswerDiff: 2 Reference: Section 17.1 20) Which of the following would NOT be a good buffer pair? A) ammonium B) chloride and ammonium hydroxide sodium C) chloride and sodium hydroxide boric acid and sodium borate D) potassium E) carbonate and potassium bicarbonate All of these are good buffer pairs. Register to View AnswerDiff: 1 Reference: Section 17-2 21) A weak acid (Ka = 10-5) and the sodium salt of its anion in solution in equimolar amounts has: A) pH > 7 B) pH < 7 C) pH = 7 D) depends only on concentration E) none of these Register to View AnswerDiff: 1 Reference: Section 17-2 22) Which of the following would NOT be considered a buffer solution? A) 0.1 M B) HC2H3O2/0.1 M NaC2H3O2 0.1 M NH3/0.1 M NH4Cl C) 0.1 M D) H2SO3/0.1 M NaHSO3 0.1 M E) HNO3/0.1 M NaNO3 0.1 M H3PO4/0.1 M NaH2PO4 Register to View AnswerDiff: 1 Reference: Section 17-2 23) Which of following dilutions will cause the pH of a 0.20 M NH3/0.02 M NH4+ buffer to drop to below the pH 7.00? A) 1 : 10 B) 1 : 100 C) 1 : 1,000 D) 1 : 10,000 E) none of these Register to View AnswerDiff: 2 Reference: Section 17-2 24) The Hasselbach equation, used to calculate the pH of simple conjugate-pair buffer systems, would Henders be expressed for an ammonia/ammonium chloride buffer, for which K (NH ) is 1.8 10-5, as: b 3 onA) pH = 4.74 + B) log([NH3]/[NH4+]) pH = 4.74 + C) log([NH4+]/[NH3]) pH = 9.25 + D) log([NH3]/[NH4+]) pH = 9.25 + E) log([NH4+]/[NH3]) pH = 14.0 - log(1.8 10-5) Register to View AnswerDiff: 2 Reference: Section 17-2 25) What is the buffer range (for an effective 2.0 pH unit) for a benzoic acid/sodium benzoate buffer? [Ka for benzoic acid is 6.3 10-5] A) 8.8 - 10.8 B) 7.4 - 9.4 C) 5.3 - 7.3 D) 4.7 - 6.7 E) 3.2 - 5.2 Register to View AnswerDiff: 3 Reference: Section 17-2 26) Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.20 M KOH A) red B) yellow C) red-yellow D) mixture The indicator is its original color. E) There is not enough information to answer this question. Register to View AnswerDiff: 2 Reference: Section 17-3 27) Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.1 M NaCl A) red B) yellow C) red-yellow D) mixture The indicator is its original color. E) There is not enough information to answer this question. Register to View AnswerDiff: 2 Reference: Section 17-3 28) Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.10 M NH4NO3 A) red B) yellow C) red-yellow D) mixture The indicator is its original color. E) There is not enough information to answer this question. Register to View AnswerDiff: 2 Reference: Section 17-3 29) Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.10 M HC2H3O2 A) red B) yellow C) red-yellow D) mixture The indicator is its original color. E) There is not enough information to answer this question. Register to View AnswerDiff: 2 Reference: Section 17-3 30) What factor governs the selection of an indicator for a neutralization titration? A) the final B) volume of the solution the volume of titrant C) the molarity of the standard solution D) the pH at the stoichiometric (equivalence) point E) the solubility of the indicator Register to View AnswerDiff: 2 Reference: Section 17-3 31) Phenolph thalein may be used as an indicator for the titration of: A) a weak base B) with a strong acid a weak acid C) with a weak base any acid and base D) a weak acid E) with a strong base phenolphthalei n cannot be used as an indicator Register to View AnswerDiff: 2 Reference: Section 17-3 32) Which of following is NOT typical of a titration curve for the titration of a strong acid by a strong base? the A) The beginning pH is low. B) The pH change is slow until near the equivalence point. C) At the D) equivalence point, pH changes by a large value. Beyond the E) equivalence point, pH again rises slowly. The equivalence point would be at a pH less than 3.5. Register to View AnswerDiff: 2 Reference: Section 17-3 33) Phenol red indicator changes from yellow to red in the pH range from 6.6 to 8.0. State what color the indicator will assume in the following solution: 0.10 M NaCN A) red B) yellow C) red-yellow D) mixture The indicator is its original color. E) There is not enough information to answer this question. Register to View AnswerDiff: 2 Reference: Section 17-3 Use the information below to answer the following question(s). methyl orange: red at pH < 3.1: orange at pH 3.1-4.4: yellow-orange above pH 4.4 litmus: red at pH < 4.5: purple at pH 4.5-8.3: blue above pH 8.3 thymol blue: yellow at pH < 8.0: green at pH 8.0-9.6: blue above pH 9.6 trinitrobenzene: colorless at pH < 12: yellow at pH 12.0-1: orange above pH 14.0 34) Which of indicators from the following table would be most appropriate for the titration of 0.30 M acetic the pH acid (Ka = 1.8 10-5) with 0.15 M sodium hydroxide? A) methyl orange B) litmus C) thymol blue D) trinitrobenzen e E) none of these Register to View AnswerDiff: 3 Reference: Section 17-3 35) Which of indicators from the following table would be most appropriate for the titration of 0.30 M the pH hydrochloric acid with 0.15 M sodium hydroxide? A) methyl orange B) litmus C) thymol blue D) trinitrobenzen e E) none Register to View AnswerDiff: 3 Reference: Section 17-3 36) Which of indicators from the following table would be most appropriate for the titration of 0.30 M the pH hydroxlamine (Kb = 9.1 10-9) with 0.15 M hydrochloric acid? A) methyl orange B) litmus C) thymol blue D) trinitrobenzen e E) none Register to View AnswerDiff: 3 Reference: Section 17-3 37) Which of following is NOT typical of a titration curve for the titration of a weak acid by a strong base? the A) There is an B) initial increase in the pH as the titration begins. Over a long C) section of the curve before the equivalence point, pH changes slightly. At the halfD) neutralization point, pH = pKa for the acid used. The steep part of the curve, near the equivalence point, is over a large pH range. E) The equivalence point would be at a pH greater than 7.0. Register to View AnswerDiff: 3 Reference: Section 17-3 38) Which condition characterizes the stoichiometric point of a neutralization titration? A) Equivalent B) amounts of acid and base have reacted. The pH is C) exactly 7.0 The indicator changes color. D) A slight excess of titrant is present. E) A slight excess of indicator is present. Register to View AnswerDiff: 1 Reference: Section 17-4 39) Choose the correct statement. A) 30 mL of 2 B) molar H3PO4 will exactly react with 15 mL of a 2 molar NaOH solution. One liter of 1 molar HCl will exactly neutralize 2 liters of 0.5 molar NaOH. C) A 1 molal D) solution always contains exactly 1 mole in a liter of solution. One liter of a 1 of an acid always exactly neutralizes one liter of a one molar solution of a base. molar solution E) A 1 molar solution requires 2 moles of H2SO4 per liter of solution. Register to View AnswerDiff: 1 Reference: Section 17-4 40) The solution that is added from the burret during a titration is the: A) buffer B) titrant C) indicator D) base E) none of these Register to View AnswerDiff: 1 Reference: Section 17-4 41) In the of 50.0 mL of 0.0200 M C6H5COOH(aq) with 0.100 M KOH(aq), what is/are the major species in titration the solution after the addition of 5.0 mL of NaOH(aq)? A) C6H5COOH, B) C6H5COO-, and Na+ C6H5COOH C) C6H5COOD) and Na+ C6H5COOH, OH-, and Na+ Register to View AnswerDiff: 2 Reference: Section 17.4 42) For the determine whether the solution at the equivalence point is acidic, basic or neutral and why: following HCl is titrated with NH3(aq) titration, A) acidic because of hydrolysis of NH4+ B) basic because C) of hydrolysis of NH3 acidic because of hydrolysis of ClD) acidic because of hydrolysis of HCl E) neutral salt of strong acid and strong base Register to View AnswerDiff: 2 Reference: Section 17-4 43) For the titration, determine whether the solution at the equivalence point is acidic, basic or neutral and following why: KOH is titrated with HI(aq) A) basic because of hydrolysis of K+ B) basic because of hydrolysis of KOH C) acidic because of hydrolysis of OHD) acidic because of hydrolysis of HI E) neutral salt of strong acid and strong base Register to View AnswerDiff: 2 Reference: Section 17-4 44) The titration curve for 10.0 mL of 0.100 M H3PO4(a q) with 0.100 M NaOH(a q) is given below. Estimate the pKa2 of H3PO4. A) 7.2 B) 4.8 C) 9.8 D) 2.2 Register to View AnswerDiff: 2 Reference: Section 17.4 45) In a solution labeled "0.010 M H2SO4(aq)," the pH is A) ~1.9. B) = 2.0. C) ~2.2. D) = 1.0. Register to View AnswerDiff: 2 Reference: Section 17.4 46) In the ation of 50.0 mL of 0.1 M BOH (a weak base with Kb = 1.6 10-7) with 0.10 M H2SO4, the neutraliz most correct description of the solution at the mid-point of the titration, i.e., half neutralized, is: A) a solution in B) which [B+] essentially equals [BOH] a solution in C) which [B+] essentially equals 4 10-4 M a solution is 75 mL and contains some undissociated BOH molecules and some B+, OH-, and whose volume HSO4- ions D) a solution E) containing SO42- and B2+ ions a solution in contact with BSO4 solid Register to View AnswerDiff: 2 Reference: Section 17-4 47) Choose the expression that gives the molar concentration of a H2SO4 solution if 24.3 mL of a 0.105 M NaOH solution is required to titrate 60 mL of the acid: A) (60 B) 24.3)/0.105 (60 2)/(24.3 0.105) C) (24.3 D) 0.105)/(60) (24.3 E) 0.105)/(60 2) (60 0.105)/(2 24.3) Register to View AnswerDiff: 2 Reference: Section 17-4 48) Why is it NOT practical to titrate ammonia with acetic acid? A) The change in pH near the end point is not large enough to be accurately detected. B) There is no C) known indicator which changes color at the right pH. The reaction is too slow. D) There is not E) enough difference between the ionization constants of ammonia and acetic acid. Ammonia does not react with acetic acid. Register to View AnswerDiff: 2 Reference: Section 17-4 49) A unknown acid had a pH of 3.70. Titration of a 25.0 ml aliquot of the acid solution required 21.7 solution ml of 0.104 M sodium hydroxide for complete reaction. Assuming that the acid is monoprotic, of an what is its ionization constant? A) 9.0 10-2 B) 2.0 10-4 C) 4.4 10-7 D) 3.6 10-9 E) 2.7 10-11 Register to View AnswerDiff: Reference: 2 Section 17-4 50) For the titration, determine whether the solution at the equivalence point is acidic, basic or neutral and following why: nahco3(aq) titrated with NaOH(aq) A) basic because of excess OHB) acidic because of hydrolysis of HCO3C) acidic because of hydrolysis of Na+ D) neutral salt of strong acid and strong base E) basic because of hydrolysis of CO32- Register to View AnswerDiff: 3 Reference: Section 17-4 51) A 0.10 M solution of Na2HPO4(aq) has a pH of A) 9.79. B) 4.68. C) 7.20. D) 12.38. Register to View AnswerDiff: 2 Reference: Section 17.5 52) In a prepared by mixing equal volumes of 0.20 M acetic acid and 0.20 M hydrobromic acid, the solution common ion is: A) BrB) C2H3O22C) H2C2H3O2 D) H2Br+ E) H3O+ Register to View AnswerDiff: 1 Reference: Section 17-1 53) Determin of the following solution. Initial concentrations are given. e the pH [HC2H3O2] = 0.250 M, [HCl] = 0.120 M [Ka = 1.8 10-5] A) 0.60 B) 0.92 C) 0.43 D) 4.74 E) 13.08 Register to View AnswerDiff: 1 Reference: Section 17-1 54) Determin [C2H3O2-] of the following solution. Initial concentrations are given. e the [HC2H3O2] = 0.250 M, [HI] = 0.120 M [Ka = 1.8 10-5] A) 8.6 10-6 B) 3.8 10-5 C) 1.8 10-5 D) 0.25 E) 0.37 Register to View AnswerDiff: 1 Reference: Section 17-1 55) Determin of the following solution. Initial concentrations are given. e the pH [HF] = 1.296 M, [HCl] = 1.045 M, Ka for HF is 6.6 10-4 A) 14 B) 3.1 C) 3.2 D) -0.019 E) 0.60 Register to View AnswerDiff: 1 Reference: Section 17-1 56) Calculate a 1.00 L solution of 0.100 M NH3(aq) after the addition of 0.010 mol HCl(g). For NH3, pKb = the pH of 4.74. A) 10.21 B) 9.26 C) 8.31 D) 11.46 Register to View AnswerDiff: 2 Reference: Section 17.1 57) Determin of the following solution. Initial concentrations are given. e the [F-] [HF] = 1.296 M, [NaF] = 1.045 M, Ka for HF is 6.6 10-4 A) 1.046 B) 2.344 C) 5.3 10-4 D) 8.2 10-4 E) 0.251 Register to View AnswerDiff: 2 Reference: Section 17-1 58) Calculate a 1.00 L solution of 0.100 M NH3(aq) after the addition of 0.010 mol NH4Cl(s). For NH3, pKb = the pH of 4.74. A) 10.26 B) 9.26 C) 8.26 D) 11.56 Register to View AnswerDiff: 2 Reference: Section 17.1 59) What is a solution prepared by mixing equal volumes of 0.10 M hydrochloric and 0.1 M hydrofluoric the pH of acid? [K for HF is 6.6 10-4] a A) 1.0 B) 1.3 C) 1.6 D) 2.2 E) 5.0 Register to View AnswerDiff: 2 Reference: Section 17-1 60) Assumin volume change on mixing, what mass of ammonium chloride should be added to 250.0 mL of g no 0.25 M ammonia to produce a solution of pH 10.70? [Kb for ammonia is 1.8 10-5] A) 3.7 mg B) 120 mg C) 40 mg D) 30 mg E) 80 mg Register to View AnswerDiff: 3 Reference: Section 17-1 61) Determin of the following solution. Initial concentrations are given. e the pH [HC2H3O2] = 0.250 M, [NaC2H3O2] = 0.120 M [Ka = 1.8 10-5] A) 5.1 B) 4.4 C) 8.9 D) 9.6 E) 7.0 Register to View AnswerDiff: 1 Reference: Section 17-2 62) Determin of the following solution. Initial concentrations are given. e the pH [HF] = 1.296 M, [NaF] = 1.045 M, Ka for HF is 6.6 10-4 A) 10.73 B) 3.27 C) 3.18 D) 3.09 E) 11.91 Register to View AnswerDiff: 1 Reference: Section 17-2 63) A weak acid has Ka = 4.2 10-3. If [A-] = 2.0 M, what must [HA] be so that [H+] = 2.1 10-3 M? A) 1.5 M B) 2.0 M C) 1.0 M D) 0.5 M E) none of these Register to View AnswerDiff: 2 Reference: Section 17-2 64) A weak acid has Ka = 1.00 10-3. If [HA] = 1.00 M what must be [A-] for the pH to be 2.7? A) 0.50 M B) 2.0 M C) 2.7 M D) 0.37 M E) none of these Register to View AnswerDiff: 2 Reference: Section 17-2 65) A buffer by adding 2.4 g of ammonium nitrate to 100.0 mL of 0.30 M ammonia (K = 1.8 10-5). To this b was solution was then added 10.0 mL of 0.30 M sodium hydroxide, which caused a pH change of: prepared A) 3.0 pH units B) 0.30 pH units C) 0.90 pH units D) 0.09 pH units E) zero Register to View AnswerDiff: 3 Reference: Section 17-2 66) A pH 4.88 buffer was prepared by dissolving 0.10 mol of benzoic acid (Ka = 6.3 10-5) and 0.50 mol of sodium benzoate in sufficient pure water to form a 1.00 L solution. To a 70.0 mL aliquot of this solution was added 2.00 mL of 2.00 M HI. What was the pH of the new 72.0 mL solution? A) 2.84 B) 3.16 C) 3.36 D) 4.64 E) 4.88 Register to View AnswerDiff: 3 Reference: Section 17-2 67) The of a solution may be defined as the number of moles of H+ that will change the pH of 1.00 L of buffer the buffer by 1.00 pH units. What is the buffer capacity of a solution which is 0.10 M in acetic capacity acid (K = 1.8 10-5) and 0.30 M in sodium acetate, in units of mol (H+) per liter? a A) 0.20 B) 0.10 C) 0.087 D) 0.009 E) zero Register to View AnswerDiff: 3 Reference: Section 17-2 68) For HClO2, Ka = 1.2 10-2. What is the pH of a solution in which [NaClO2] = 0.193 M and [HClO2] = 0.203 M? A) 3.32 B) 0.11 C) 1.92 D) 1.94 E) 1.90 Register to View AnswerDiff: 1 Reference: Section 17-2 69) An acid = 1 10-6. At what pH would this acid and its corresponding salt make a good buffer? has a Ka A) 6 B) 7 C) 8 D) 5 E) 4 Register to View AnswerDiff: 1 Reference: Section 17-2 70) A has [HC7H5O2] = 0.100 M and [Ca(C7H5O2)2] = 0.200 M. Ka = 6.3 10-5 for HC7H5O2. The solution solution volume is 5.00 L. What is the pH of this solution after 5.00 ml 10.0 M HCl is added? A) 4.80 B) 4.86 C) 4.65 D) 4.70 E) 4.75 Register to View AnswerDiff: 2 Reference: Section 17-2 71) A [HC7H5O2] = 0.100 M and [Ca(C7H5O2)2] = 0.200 M. Ka = 6.3 10-5 for HC7H5O2. The solution solution volume is 5.00 L. What is the pH of the solution after 10.00 ml of 5.00 M NaOH is has added? A) 4.80 B) 4.86 C) 4.65 D) 4.70 E) 4.75 Register to View AnswerDiff: 2 Reference: Section 17-2 72) What is a buffer solution prepared by dissolving 25.5 g NaC2H3O2 in a sufficient volume of 0.550 M the pH of HC H O to make 500.0 mL of buffer? 232 A) 4.74 B) 4.68 C) 4.91 D) 4.57 E) 480 Register to View AnswerDiff: 2 Reference: Section 17-2 73) A k states that to prepare a particular buffer solution mix 63.0 mL of 0.200 M HC2H3O2 with 37.0 handboo mL of 0.200 M NaC2H3O2. What is the pH of this buffer? (Ka = 1.8 10-5) A) 4.74 B) 4.51 C) 4.98 D) 5.33 E) 7.00 Register to View AnswerDiff: 2 Reference: Section 17-2 74) What is solution made by dissolving 2.16 g of sodium benzoate (NaC6H5CO2) in a sufficient volume of the pH of 0.033 M benzoic acid solution to prepare 500.0 mL of buffer? [Ka for benzoic acid is 6.3 10-5] a A) 4.23 B) 4.37 C) 4.64 D) 5.77 E) 6.30 Register to View AnswerDiff: 2 Reference: Section 17-2 75) If 30.0 mmol HCl(g) is added to 1.00 L of a buffer that is 0.340 M NH3(aq) and 0.290 M NH4Cl(aq), what are the final concentrations of NH3(aq) and NH4Cl(aq), respectively? Assume no volume change. A) 0.310 M and B) 0.320 M 0.310M and C) 0.290 M 0.370 M and D) 0.290 M 0.370 M and 0.320 M Register to View AnswerDiff: 2 Reference: Section 17.2 76) What is the pH of a buffer that is 0.88 M HCN(aq) and 0.53 M NaCN(aq)? The Ka of HCN is 6.2 x 10-10. A) 8.99 B) 9.21 C) 9.43 D) 4.79 Register to View AnswerDiff: 2 Reference: Section 17.2 77) A buffer M C6H5COOH(aq) and 0.282 M Na(C6H5COO)(aq). Calculate the pH after the addition of is 0.282 0.150 moles of nitric acid to 1.0 L of the buffer. For C H COOH, pK = 4.20. 65 a A) 3.69 B) 4.20 C) 4.71 D) 3.87 Register to View AnswerDiff: 2 Reference: Section 17.2 78) All of the following will result in the production of a buffer except A) mixing equal B) volumes of 0.10 M NaC2H3O2(aq) and 0.10 M HCl(aq). mixing equal C) volumes of 0.10 M NaC2H3O2(aq) and 0.050 M HCl(aq). mixing equal D) volumes of 0.10 M NaC2H3O2(aq) and 0.10 M HC2H3O2(aq). mixing equal volumes of 0.10 M HC2H3O2(aq) and 0.050 M NaOH(aq). Register to View AnswerDiff: 2 Reference: Section 17.2 79) How of 0.200 M acetic acid are mixed with 13.2 mL of 0.200 M sodium acetate to give a buffer with many mL pH = 4.2? A) 37 mL B) 18 mL C) 3.8 mL D) 13 mL E) 46 mL Register to View AnswerDiff: 2 Reference: Section 17-2 80) What mass of sodium acetate should be dissolved in 250.0 mL of 0.30 M acetic acid to form a buffer of pH 5.0? [Ka for acetic acid is 1.8 10-5] A) 11 g B) 8.0 g C) 7.5 g D) 5.0 g E) 1.4 g Register to View AnswerDiff: 2 Reference: Section 17-2 81) What is the change in pH after addition of 10.0 mL of 1.0 M sodium hydroxide to 90.0 mL of a 1.0 M NH3/1.0 M NH4+ buffer? [Kb for ammonia is 1.8 10-5] A) 1.0 pH unit B) 0.1 pH unit C) 0.01 pH unit D) 0.001 pH unit E) zero Register to View AnswerDiff: 3 Reference: Section 17-2 82) A pH 9.56 buffer was prepared by mixing 2.00 moles of ammonia (Kb for ammonia is 1.8 10-5) and 1.00 mol of ammonium chloride in water to form a solution with a volume of 1.00 L. To a 200.0 mL aliquot of this solution was added 10.0 mL of 10.0 M sodium hydroxide. What was the resulting pH? A) 9.28 B) 9.56 C) 9.95 D) 10.50 E) 13.7 Register to View AnswerDiff: 3 Reference: Section 17-2 83) A k states that to prepare a particular buffer solution mix 39.0 mL of 0.20 M NaH2PO4 with 61.0 handboo mL of Na HPO . What will be the pH of this buffer? 2 4 A) 7.2 B) 7.4 C) 7.0 D) 6.8 E) 6.6 Register to View AnswerDiff: 3 Reference: Section 17-2 84) The ds are available as 0.10 M aqueous solutions: pyridine (pKb = 8.82), triethylamine (pKb = following 3.25), HClO , NaOH, phenol (pK = 9.96), HClO (pK = 7.54), and NH (pK = 4.74). Identify 4 a a 3 b compoun two solutions that could be used to prepare a buffer with a pH of approximately 5. A) pyridine and B) HClO4 triethyamine C) and HClO4 phenol and D) NaOH HClO and NaOH Register to View AnswerDiff: 3 Reference: Section 17.2 85) Twenty- five milliliters of 0.10 M HCl is titrated with 0.10 M NaOH. What is the pH at equivalence? A) 7.0 B) 6.2 C) 7.5 D) 8.6 E) It cannot be determined Register to View AnswerDiff: 1 Reference: Section 17-4 86) What will the pH at the neutralization point of 0.00812 M Ba(OH)2 be when titrated with HCl? A) 7.0 B) 12.2 C) 8.0 D) 9.0 E) 6.0 Register to View AnswerDiff: 1 Reference: Section 17-4 87) What volume in mL of 2.0 M H2SO4 is needed to neutralize 7.8 g of Al(OH)3(78.0 g/mol)? Al2(SO4)3 and water are the titration products. A) 150 B) 75 C) 300 D) 500 E) none of these Register to View AnswerDiff: 1 Reference: Section 17-4 88) Twenty- milliliters of 0.10 M HCl is titrated with 0.10 M NaOH. What is the pH when 30 ml of NaOH five have been added? A) 2.0 B) 12.0 C) 12.2 D) 1.8 E) 12.3 Register to View AnswerDiff: 2 Reference: Section 17-4 89) 25 ml of 0.10 M acetic acid is titrated with 0.10 M NaOH. What is the pH before any NaOH is added? Ka for acetic acid = 1.8 10-5. A) 1.0 B) 5.7 C) 2.9 D) 4.3 E) 2.2 Register to View AnswerDiff: 2 Reference: Section 17-4 90) What is the equivalence point for the titration of 0.20 M nitrous acid by 0.20 M sodium hydroxide? [Ka the pH at for nitrous acid is 4.5 10-4] A) 5.83 B) 7.00 C) 8.17 D) 9.00 E) 10.67 Register to View AnswerDiff: 2 Reference: Section 17-4 91) Determin of the following solution. Initial concentrations are given. e the pH [NaCHO2] = 0.815 M, [HBr] = 0.105 M, Ka (HCHO2) = 1.8 10-4 A) 2.91 B) 4.63 C) 4.57 D) 9.43 E) 11.09 Register to View AnswerDiff: 2 Reference: Section 17-4 92) Twenty- milliliters of 0.10 M HCl is titrated with 0.10 M NaOH. What is the pH before any NaOH is five added? A) 0.40 B) 2.5 C) 0.1 D) 1.0 E) 25 Register to View AnswerDiff: 2 Reference: Section 17-4 93) Twenty- milliliters of 0.10 M HCl is titrated with 0.10 M NaOH. What is the pH after 15 ml of NaOH has five been added? A) 1.4 B) 1.2 C) 1.0 D) 2.0 E) 1.6 Register to View AnswerDiff: 2 Reference: Section 17-4 94) If 25 mL of 0.20 M NaOH is added to 50 mL of 0.10 M HC H O (K = 1.8 10-5), what is the pH? 232 a A) 5.33 B) 10.21 C) 8.78 D) 13.56 E) 1.34 Register to View AnswerDiff: 2 Reference: Section 17-4 95) 25 ml of 0.10 M acetic acid is titrated with 0.10 M NaOH. What is the pH after 15 ml of NaOH have been added? Ka for acetic acid = 1.8 10-5. A) 7.0 B) 4.3 C) 4.7 D) 4.9 E) 4.6 Register to View AnswerDiff: 2 Reference: Section 17-4 96) 25 ml of 0.10 M acetic acid is titrated with 0.10 M NaOH. What is the pH at the equivalence point? Ka for acetic acid = 1.8 10-5. A) 7.0 B) 10.6 C) 5.3 D) 8.7 E) 9.4 Register to View AnswerDiff: 2 Reference: Section 17-4 97) 25 ml of 0.10 M acetic acid is titrated with 0.10 M NaOH. What is the pH after 30 ml of NaOH have been added? Ka for acetic acid = 1.8 10-5. A) 12.0 B) 2.0 C) 12.2 D) 8.7 E) 12.3 Register to View AnswerDiff: 2 Reference: Section 17-4 98) What volume in ml of 0.05 M NaOH would have to be added to 50.0 ml of 0.10 M H2SO4 in order to affect complete neutralization of the acid? A) 50 ml B) 20 ml C) 100 ml D) 150 ml E) 10 ml Register to View AnswerDiff: 2 Reference: Section 17-4 99) 1.80 an impure mixture containing sodium carbonate required 84.0 ml of 0.125 M H2SO4 for grams of complete neutralization. What percent of the mixture is sodium carbonate? A) 62% B) 31% C) 120% D) 57% E) 1.1% Register to View AnswerDiff: 2 Reference: Section 17-4 100) Determin of the following solution. Initial concentrations are given. e the pH [NH3] = 1.20 M, [KOH] = 0.320 M, Kb (NH3) = 1.8 10-5 A) 13.5 B) 8.7 C) 9.8 D) 11.7 E) 12.2 Register to View AnswerDiff: 3 Reference: Section 17-4 101) What is a 0.30 M trisodium phosphate solution? [K for monohydrogen phosphate ion is 4.2 10-13] a the pH of A) 13.3 B) 12.7 C) 10.5 D) 9.8 E) 8.6 Register to View AnswerDiff: 1 Reference: Section 17-5 102) What is the pH of a 1.0 M solution of Na3AsO4. Ka1 = 6 10-3, Ka2 = 1 10-7, Ka3 = 3 10-12 ? A) 2.5 B) 7.0 C) 8.2 D) 11.5 E) 5.8 Register to View AnswerDiff: 1 Reference: Section 17-5 103) What is the pH of a 1.0 M solution of Na2SO3? Ka1 = 1.3 10-2, Ka2 = 6.2 10-8 ? A) 6.8 B) 7.2 C) 7.0 D) 10.4 E) 3.6 Register to View AnswerDiff: 1 Reference: Section 17-5 104) What is a 1.0 M solution of trisodium phosphate? K = 7.1 10-3, K = 6.3 10-8, K = 4.2 10a1 a2 a3 the pH of 13 A) 1.6 B) 7.0 C) 12.4 D) 6.2 E) 7.8 Register to View AnswerDiff: 1 Reference: Section 17-5 105) Calculate the pH of an aqueous solution that is 1.0 M Na CO . K for H CO is 4.7 10-11. 2 3 a2 2 3 A) 8.8 B) 10.3 C) 3.7 D) 12.2 E) 1.8 Register to View AnswerDiff: 2 Reference: Section 17-5 ... View Full Document

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