Chemistry 12 Provincial Exam Workbook Unit 04: Acid Base Equilibria. Multiple Choice Questions

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1 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / 69 Chemistry 1 Provincial Exam Workbook Unit 0: Acid Base Equilibria Multiple Choice Questions 1. Calculate the volume of 0.00 M HNO needed to completely neutralize 5.0 ml of A. 10. ml B ml C. 0.8 ml D. 1.7 ml 0.50 M Sr OH.. Equal moles of which of the following chemicals could be used to make a basic buffer solution? A. HF and NaOH B. HCl and NaCl C. KBr and NaNO D. NH and NHCl. Which reaction occurs when calcium oxide is added to water? A. CaO(s) Ca O (aq) B. CaO(s) Ca(aq) O (aq) CaO(s) H O(l) Ca OH (aq) C. CaO(s) H O(l) CaOH(aq) O (aq) D.. In which of the following is HSO acting as a Brönsted-Lowry acid? HSO H O H SO OH A. B. NH HSO NH SO C. HSO HPO H SO PO D. HCO HSO HCO HSO

2 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / What is the conjugate base of HPO? A. OH B. PO C. HPO D. HPO 6. Which of the following is correct if the four solutions listed are compared to one another? 7. Which of the following is the strongest acid that can exist in an aqueous solution? O A. B. NH C. HO D. HClO 8. Which of the following household products could have a ph = 1.0? A. soda pop B. tap water C. lemon juice D. oven cleaner 9. What is the ph of a M KOH solution? A. 0.0 B. 1.0 C D. 1.70

3 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / What is the value of K b for HPO? A. 1.x10 1 B. 6.x10 8 C. 1.6x10 7 D. 7.5x Which of the following describes the net ionic reaction for the hydrolysis of NHCl(s)? A. NH (aq) Cl (aq) NH Cl(s) NH Cl(s) NH (aq) Cl (aq) B. C. Cl (aq) HO(l) HCl(aq) OH (aq) NH (aq) H O(l) NH (aq) H O (aq) D. 1. Which of the following salts will produce a solution with the highest ph? A. 1.0 M NaNO B. 1.0 M NaHSO C. 1.0 M NaHCO D. 1.0 M NaHPO 1. What is true about the transition point of all indicators described by the following equilibrium HIn H O H O In A. ph Ka B. HIn In 7 C. HO 1.0x10 M D. moles of HO equals moles of OH

4 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / A chemical indicator has a the identity of the indicator? Ka 6.0x10. What is the ph at the transition point and 15. A 0.0 ml sample of HCl is titrated with 5.0 ml of 0.0 M Sr OH. What is the concentration of the acid? A. 0.1 M B. 0.0 M C. 0.5 M D M 16. Which of the following is the net ionic equation for the neutralization of HNO (aq) with Sr OH (aq)? A. H (aq) OH (aq) HO(l) Sr (aq) NO (aq) Sr NO (aq) H O(l) B. C. D. HNO (aq) Sr OH (aq) Sr NO (aq) H O(l) H (aq) NO (aq) Sr (aq) OH (aq) Sr (aq) NO (aq) H O(l) 17. When a strong acid is titrated with a strong base, what will the ph value be at the equivalence point? A. 0.0 B. 6.8 C. 7.0 D Which of the following acids could not be present in a buffer solution? A. HF B. HNO C. HSO D. HClO

5 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 5 / Which net ionic equation best describes the reaction between NaOH and HS? A. OH (aq) H (aq) HO(l) B. OH (aq) H S(aq) H O(l) S (aq) C. D. NaOH(aq) H S(aq) H O(l) Na S(aq) Na (aq) OH (aq) H (aq) S (aq) H O(l) Na (aq) S (aq) 0. Which of the following is a general characteristic of Arrhenius acids? A. They produce H in solution B. They accept an H from water C. They turn bromthymol blue a blue colour D. They react with HO ions to produce H 1. Identify a conjugate pair from the equilibrium provided PO HCO HPO CO A. CO and PO B. PO and HCO C. D. HCO and HPO. Which of the following best describes a weak acid? A. Its 0.10 M solution will have ph of 1.00 B. It may be very soluble, but only partly ionized C. It must be very soluble and completely ionized D. It must be of low solubility and completely ionized. What is the ph at the transition point for an indicator with a K a of A..5x10 B..60 C D x10?

6 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 6 / 69. What volume of M NaOH is required to completely neutralize ml of M HPO? A ml B ml C. 0.0 ml D. 5.0 ml 5. What is the ph of the solution formed when moles NaOH is added to 1.00 L of M HCl? A..00 B C D Which of the following graphs describes the relationship between the ph of a buffer and the volume of NaOH added to the buffer? 7. A gas which is produced by internal combustion engines and contributes to the formation of acid rain is A. H B. O C. CH D. NO

7 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 7 / Consider the following reaction H BO (aq) HS (aq) H BO (aq) H S(aq) A. acid, base, base, acid B. acid, base, acid, base C. base, acid, acid, base D. base, acid, base, acid The order of Brönsted-Lowry acids and bases in this equation is 9. The conjugate base of an acid is produced by A. adding a proton to the acid B. adding an electron to the acid C. removing a proton from the acid D. removing an electron from the acid 0. Which of the following represents the predominant reaction between HCO water? and A. HCO HO CO HCO H O H CO OH B. C. HCO H O H O CO D. HCO H O H O CO OH CO 1. Water acts as an acid when it reacts with which of the following? A. I and IV only B. II and III only C. I, II and IV only D. II, III and IV only

8 . A A. weak acid B. weak base C. strong acid D. strong base 1.0x10 M R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 8 / 69 solution has a ph of The solute is a. Consider the following Brönsted-Lowry equilibrium system HSO H PO SO H PO A. HSO and SO What are the two Brönsted-Lowry bases in the equilibrium above? B. H PO and SO C. HSO and HPO D. HPO and HPO. Which of the following will have the lowest electrical conductivity? A. 1.00M HCl B. 1.00M HNO C. 1.00M HSO D. 1.00M HPO 5. Which of the following represents the ionization of water? A. HO H 0.5O H O H O OH B. C. HO O HO H O 0.5O H e D.

9 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 9 / Which of the following are amphiprotic? A. I and II only. B. I and III only. C. II and III only. D. I, II and III. 7. Consider the following equilibrium: H O(l) energy H O (aq) OH (aq) The temperature is increased and a new equilibrium is established. The new equilibrium can be described by A. B. C. D. ph poh and K 1.0x10 ph poh and K 1.0x10 ph poh and K 1.0x10 ph poh and K 1.0x10 W W W W What is the HO at the equivalence point for the titration between HBr and KOH? 9 A. 1.0x10 M 7 B. 1.0x10 M 5 C. 1.0x10 M D. 0.0 M 9. Which of the following would form a buffer solution when equal moles are mixed together? A. HCl and NaCl B. HCN and NaCN C. KNO and KOH D. NaSO and NaOH

10 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 10 / Which of the following oxides dissolves to form a solution with a ph greater than 7? A. SO B. CO C. NO D. KO 1. The ph of acid rain could be A. 5.0 B. 7.0 C. 9.0 D A hydronium ion has the formula A. H B. OH C. HO D. HO. The conjugate acid of C6H5NH is A. C6H5NH B. C6H5NH C. C6H5NH D. C6H5NH. Which of the following is a property of 1.0 M HCl but not a property of 1.0 M CH COOH? A. turns litmus red B. ionizes completely C. has a ph less then 7.0 D. produces HO in solution

11 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 11 / In a 1.0 M HF solution, the concentration of HF, F, and OH, from highest to lowest is A. B. F HF OH C. OH HF F D. OH F HF 6. In which of the following reactions is water behaving as a Brönsted-Lowry acid? A. HO H O HCl H O H O Cl B. C. NH HO NH OH D. NH HO HO NH 7. What is the OH of a solution with HO 9.x10 M? A. B. C. D x10 M 1 8.6x10 M 1 1.1x10 M 9.x10 M 8. The ph of 0.10 M HNO is A B C. 1.6 D What term is used to describe the point at which a chemical indicator changes colour? A. titration point B. transition point C. equivalence point D. stoichiometric point

12 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / When 5.0 ml samples of the strong acid HSO were titrated with 0.5 M NaOH the following results were obtained A. 0.0 M B. 0.1 M C. 0.0 M D. 0. M What is the concentration of the HSO sample? 51. Which of the following equations describes the predominant reaction that occurs at the equivalence point of a titration between CH COOH(aq) and NaOH(aq)? A. H (aq) OH (aq) HO(l) CH COO (aq) H O(l) CH COOH(aq) OH (aq) B. C. CHCOOH(aq) NaOH(aq) NaCH COO(aq) HO(l) H (aq) CH COO (aq) Na (aq) OH (aq) Na (aq) CH COO (aq) H O(l) D. 5. Why is the solution below not considered to be a true buffer solution? A. excessive HCN B. excessive HO C. insufficient CN HCN D. insufficient HCN(aq) HO (aq) CN (aq) HO(l) M.x10 M.x10 M

13 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / What could be added to 1.0 L of the solution below in order for it to behave as a true buffer? HCN(aq) HO (aq) CN (aq) HO(l) M.x10 M.x10 M A. 1.0 mol HCl B. 1.0 mol HCN C. 1.0 mol HO D. 1.0 mol NaCN 5. Which of the following equations correctly represents the reaction of a metallic oxide with water? A. KO HO KOH B. SO HO HSO C. NaO HO NaO H D. NaOH HO Na HO 55. A definition for a Brönsted-Lowry acid should contain which of the following phrases? A. the donation of H B. the donation of OH C. the acceptance of H D. the acceptance of OH 56. Which equation represents the reaction of a Brönsted-Lowry base with water? A. Na HO NaOH H N H H O N H OH B. 5 C. HPO H O H O PO D. HCO HO HO HCO

14 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / Given the equilibrium H BO H PO H BO HPO A. HPO B. HBO C. HPO D. HBO Which is the strongest acid? 58. Which species will result in a solution with the greatest HO? A. NaCN B. NaPO C. NaCO D. NaCO 59. Which species is not amphiprotic? A. HO B. HBO C. HPO D. HC6H5 O At a given temperature a sample of pure water has a ph = Which of the following is true?

15 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 15 / Which of the following is a definition of ph? A. ph log HO B. ph poh 1 C. ph log HO D. ph poh pkw 6. What is the mass of NaOH required to prepare ml of NaOH(aq) that has a ph of 1.6? A. 0.8 g B. 0. g C g 1 D..0x10 g 6. Which of the following hypothetical acids would have the lowest conductivity? 6. What is the net ionic equation for the hydrolysis of NHCl? NH Cl(aq) NH (aq) Cl (aq) A. B. Cl (aq) HO(l) HCl(aq) OH (aq) NH (aq) H O(l) H O (aq) NH (aq) C. D. NH (aq) H O(l) HNH (aq) OH (aq) 65. What is the approximate ph of a 0.1 M solution of the salt NHCl? A. 1.0 B. 5.0 C. 7.0 D. 9.0

16 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 16 / Consider the following indicator equilibrium HIn(aq) In (aq) HO HO (aq) colourless blue What is the effect of adding HCl to a blue sample of this indicator? 67. An indicator has a Ka 6 x10. Which of the following is true for this indicator? 68. Oxalic acid dihydrate is a pure, stable, crystalline substance. Which of the following describes one of its uses in acid-base titrations? A. buffer B. primary standard C. chemical indicator D. stoichiometric indicator 69. What is the net ionic equation that describes the reaction of HCl(aq) with PbOH (s)? A. H (aq) OH (aq) HO(l) HCl(aq) Pb OH (s) PbCl (s) H O(l) B. C. D. H (aq) Cl (aq) Pb OH (s) PbCl (s) H O(l) - H (aq) Cl (aq) Pb (aq) OH (aq) Pb (aq) Cl (aq) H O(l)

17 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 17 / Which of the following would be used to prepare an acidic buffer solution? A. HF and HO B. HS and NaHS C. NH and NHCl D. HNO and NaNO 71. Four samples of rain are collected from different geographic regions and the ph is measured for each sample. A. 1 only B. 1 and C. 1, and D. 1,, and Which of the above samples would be classified as acid rain? 7. Which of the following is a characteristic that is common to bases? - A. They react with metals to produce OH. B. They produce a yellow colour in bromthymol blue solution. - C. They produce solutions with OH smaller than -7 1x10. + D. They produce solutions with HO smaller than -7 1x What is a common substance found in solid drain cleaner? A. Na B. HCl C. NaCl D. NaOH

18 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 18 / Which equation contains a Brönsted-Lowry acid-base pair? A. H (g)+o (g) H O(g) + - B. NaOH(aq) Na (aq)+oh (aq) Zn(s)+HCl(aq) H (g)+zncl (aq) C. + - D. H O(l)+HCN(aq) H O (aq)+cn (aq) 75. Which solution would have the greatest electrical conductivity? A. 0.1 M HCl B. 0.1 M NH C. 0.1 M HBO D. 0.1 M CHOH 76. Which acid has the strongest conjugate base? A. HO B. HCO C. HCO D. HCO 77. What is the equilibrium expression for the water ionization constant? A. Kw Ka Kb B. K =1.0x10 w -1 C. K w =ph+poh + - D. K w= HO OH 78. What is the + HO in ml of M NaOH? A. B. C. D x10 M -1.0x10 M -1.0x10 M -11.0x10 M 79. What is the ph of a.5 M KOH solution? A B. 0.0 C D. 1.0

19 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 19 / What is the value of K b for A. 1.x10 B. 6.x10 C. 1.6x10 D. 7.5x HPO? 81. One of the products of the reaction between HCl(aq) and NHOH(aq) undergoes hydrolysis. What is the net ionic equation for this hydrolysis reaction? + - A. NH Cl(aq) NH (aq)+cl (aq) B. Cl (aq)+h O(l) HCl(aq)+OH (aq) C. NH (aq)+h O(l) H O (aq)+nh (aq) D. HCl(aq)+NH OH(aq) NH Cl(aq)+H O(l) 8. One of the species in the chemical indicator HIn exhibits a yellow colour. If acid is added, the indicator turns red. Which of the following is correct? 8. An indicator changes colour in the phph range of 6.0 to 7.0. What is the K a for this indicator? A..0x10 B. 1.6x10 C D A 5.0 ml sample of the weak acid HS is titrated with 1.8 ml of 0.0 M NaOH (a strong base). What is the concentration of the acid? A M B. 0. M C. 0.8 M D M

20 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 0 / Which of the following is the net ionic equation for the titration reaction of NH (aq) with HCl(aq)? + - A. H (aq)+oh (aq) H O(l) + + B. NH (aq)+h (aq) NH (aq) C. NH (aq)+hcl(aq) NH Cl(aq) + + D. NH (aq)+h (aq)+cl (aq) NH (aq)+cl (aq) 86. What is the main function of a buffer solution? A. to neutralize acids B. to resist changes in ph C. to maintain solution neutrality D. to prevent acids from mixing with bases 87. Which of the following would commonly be used to prepare a buffer solution? A. HCl and KCl B. NH and NHCl C. HS and NaSO D. NaCO and NaOH 88. Which of the following represents a reaction that can occur between a non-metallic oxide and water? A. SO +HO HSO B. Na O+H O NaOH C. CaO+H O CaOH NO +H O H NO+O D. 89. Which of the following represents the results of tests on an acidic solution?

21 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / Which of the following represents a protonated water molecule? A. HO B. HO C. HO D. HO Which of the following best describes a weak base? 9. Which species will produce the greatest hydroxide ion concentration in solution? A. B. + NH - PO C. HCO - D. HCO 9. Water will react most completely as an acid with... A. - SO B. H BO C. D. - C H O 6 5 CH COO What does this equation represent? A. w K B. the ionization of water C. the ion product of water D. the equilibrium expression for water

22 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / Which of the following is correct for water? 96. What is the ph of 0.50 M LiOH? -1 A..0x10 B C. 0.0 D What is the equilibrium constant expression for the predominant equilibrium in NaHSO (aq)? A. B. C. D. + - HO SO - HSO - OH HSO - HSO NaHSO (aq) Na (aq)+hso + - HSO (aq)+h O(l) H O (aq)+so Which of the following 0.10 M solutions would have the lowest ph? A. HF B. NH C. HNO D. HCO

23 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / Which of the following describes a solution of LiClO (aq) with respect to hydrolysis? + + A. Li (aq)+h O(l) LiOH(aq)+H (aq) B. LiClO (aq)+h O(l) LiOH(aq)+HClO (aq) - - C. ClO (aq)+h O(l) OH (aq)+hclo (aq) D. No hydrolysis reaction occurs Which of the following is a basic salt solution? A. NH (aq) B. NHI(aq) C. KNO (aq) D. NaCO (aq)

24 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / 69 Written Questions 1. Calculate the ph of a 1.5 M HS solution. ( marks). Consider the following reaction HCl(aq) Ba OH (s) BaCl (aq) H O(l) When.16 g samples of BaOH were titrated to the equivalence point with an HCl solution, the following data were recorded Using the data above, calculate the original HCl. ( marks). In aqueous solutions HO is the strongest acid present. This phenomenon is called the leveling effect. Explain why this occurs. ( marks). A 1.00 M OCl solution has an OH of 5.75x10 M. A. Calculate K b for OCl. ( marks)

25 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 5 / 69 B. Calculate K a for HOCl. (1 mark) 5. Calculate the mass of HPO ( marks) needed to prepare.0 L of a solution with a ph of 6. Consider a Brönsted-Lowry acid-base equation, where HNO is a reactant and HPO is a product. A. Complete the following equation: HNO?? HPO (1 mark) B. Identify the weaker base in the equilibrium in part a). (1 mark) 7. A M solution of methylamine, CHNH, has a ph of Calculate the K b for methylamine. ( marks)

26 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 6 / A titration was performed by adding M NaOH to a 5.00 ml sample of HSO. Calculate the H SO from the following data. ( marks) 9. A sample of a weak acid was found to conduct an electric current better than a sample of a strong acid. Explain these results in terms of ion concentration. ( marks) 10. Calculate the OH of 0.10 M NH. ( marks) 11. A titration was performed by adding M HCO to a 5.00 ml sample of NaOH. The following data was collected Calculate the NaOH. ( marks)

27 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 7 / 69 B. Explain why the ph at the equivalence point is greater than 7.0. (1 mark) 1. A M solution of an unknown weak acid, HX, has a ph of 1.1. What is the K a for HX? ( marks) 1. Consider the salt ammonium acetate, NHCH COO. A. Write the equation for the dissociation of NHCH COO. (1 mark) B. Write equations for the hydrolysis reactions which occur. ( marks) C. Explain why a solution of NHCH COO has a ph of Support your answer with calculations. ( marks) 1. A. Define the term Brönsted-Lowry conjugate acid-base pair. (1 mark) Acid: B. Give an example of a conjugate acid-base pair. (1 mark) Base:

28 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 8 / Consider the acids HCl and HF A. Only one of the following reactions occurs. Complete the equation for the reaction which does occur. (1 mark) HCl F? HF Cl? B. For the reaction that occurs, are reactants or products favoured? Explain. (1 mark) C. Explain why the other reaction will not occur. (1 mark) 16. Calculate the HO of 0.10 M HNO. ( marks) 17. Write the formula equation and the net ionic equation for the reaction between 0.10 M Sr OH. ( marks) HSO and 0.10 M Formula equation: Net ionic equation: 18. Consider the following Brönsted-Lowry equilibrium: H SO (aq) HPO (aq) H PO (aq) HSO (aq) A. Identify the two Brönsted-Lowry acids in the above equilibrium. (1 mark)

29 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 9 / 69 B. Define the term conjugate acid. (1 mark) 19. A 50.0 ml sample of HCl with a ph of.000 is completely neutralized with 0.00 M NaOH. A. What volume of NaOH is required to reach the stoichiometric point? ( marks) B. Write the net ionic equation for the above neutralization reaction. (1 mark) C. If the HCl were titrated with a 0.00 M NH (aq) instead of 0.00 M NaOH, how would the volume of base required to reach the equivalence point compare with the volume calculated in part a)? Explain your answer. (1 mark) 0. Consider the following equilibrium energy H O H O OH A. Explain how pure water can have a ph of 7.0. ( marks) B. Calculate the value of K W for the sample of water with a ph of 7.0. ( marks) 1. Identify a gas which causes acid rain, and write an equation showing this gas reacting with water. ( marks)

30 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 0 / 69. Consider the 0.10 M solutions of the following two acids: A. What can you conclude about the acids that will explain these different ph values? (1 mark) You can conclude that acid HA: You can conclude that acid HB: B. Compare the volume of 0.10 M NaOH needed to neutralize equal volumes of each of these acid samples. (1 mark). Consider a 1.0 M solution of NHF A. Write both hydrolysis reactions that occur when NHF is dissolved in water. ( marks) B. Will the above NH F solution be acidic, basic, or neutral? Support your answer with calculations. ( marks)

31 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / 69. An indicator is often used during acid-base titrations A. Define the term transition point for an indicator. (1 mark) B. Calculate the K a value for methyl red. (1 mark) C. A mixture of indicators is made by combining equal amounts of methyl orange and bromthymol blue. Complete the following table, showing the colour of each indicator and the mixture at ph of 5 and ph of 9. ( marks) 5. Will HCO act predominantly as an acid or as a base in solution? Support your answer with calculations. ( marks) 6. The two reactants in an acid-base reaction are HNO (aq) and A. Write the equation for the above reaction. ( marks) - HCO (aq). B. Define the term conjugate acid-base pair. (1 mark)

32 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / 69 C. Write the formulas for a conjugate acid-base pair for the above reaction. (1 mark) 7. At 10.0 C, -15 K w =.95x10 for pure water. A. Calculate the ph of water at 10.0 C. ( marks) B. A mixture of the indicators phenolphthalein and bromcresol green is added to the water. What is the resulting colour of the mixture? Explain. ( marks) 8. At a particular temperature a 1.0 M HS solution has a ph of.75. Calculate the value of K a at this temperature. ( marks) 9. What is the main function of a buffer solution? (1 mark) 0. The ion - HPO is an amphiprotic anion. A. Define the term amphiprotic. (1 mark) B. Write the balanced equation for the reaction when - HPO reacts with HF. ( marks)

33 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / Write an equation for a reaction in which HO acts only as a Brönsted-Lowry base. ( marks). Calculate the ph of 0.5 M Sr OH. ( marks). Calculate the ph of 0.5 M NHCl. (5 marks). A 0.1 M unknown acid is titrated with 0.10 M NaOH and the following titration curve results A. Choose a suitable indicator (other than phenolphthalein) and give a reason for your choice. (1 mark) B. Is the unknown acid weak or strong? Explain. ( marks)

34 5. The cyanide ion, R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / 69 - CN, is a Brönsted-Lowry base. A. Define Brönsted-Lowry base. (1 mark) B. Write the equation representing the reaction of - CN with water. ( marks) C. Identify a conjugate pair in B. above. (1 mark) 6. Write an equation to show the ionization of water. ( marks) 7. Calculate the ph of 1.50 M NH. (5 marks) 8. Consider the following buffer equilibrium... HF(aq) H O F high concentration + - +HO(l) + low concentration high concentration Using Le Chatelier s Principle, explain what happens to the ph of the buffer solution when a small amount of NaOH is added.

35 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 5 / Consider the following equilibria A. In equation I above, the reactants are favoured. Identify the stronger acid. (1 mark) B. In equation II above, the products are favoured. Identify the stronger acid. (1 mark) - - C. Consider the following reaction HOCN+ClO OCN +HClO. Does this reaction favour reactants or products? Explain. ( marks) 0. At 60 C, the phfor pure water is Determine the value of K w at this temperature. ( marks) 1. Calculate the ph of 0.5 M HCO. ( marks). A strong acid strong base titration has a ph of 7.0 at the equivalence point. A weak acid strong base titration has a ph greater than 7.0 at the equivalence point. A. What causes the difference in these ph values? ( marks)

36 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 6 / 69 B. Select one indicator which could be used for both titrations. (1 mark). Write a chemical reaction showing an amphiprotic anion reacting as a base in water. ( marks). Calculate the poh of 0.5 M Sr OH. ( marks) 5. A.00 M diprotic acid has a ph of Calculate the K a value. (5 marks) 6. The following two experiments were conducted Titration A Titration B A strong acid was titrated with a strong base. A weak acid was titrated with a strong base. A. How does the ph at the equivalence point of Titration B compare with the ph at the equivalence point in titration A? (1 mark) B. Explain your answer to A. ( marks) 7. An acid-base reaction occurs between - HSO and - IO. Write the equation for the equilibrium that results. (1 mark)

37 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 7 / 69 B. Identify one conjugate acid base pair in the reaction. (1 mark) C. State whether reactants or products are favoured and explain how you arrived at your answer. ( marks) 8. At 10 C, -15 K w =.95x10. A. Determine the ph of water at 10 C. ( marks) B. State whether water at this temperature is acidic, basic or neutral, and explain. (1 mark) 9. Calculate the ph of 0.50 M HS. ( marks) 50. Outline a procedure to prepare a buffer solution. ( marks) 51. Calculate the ph of a 0.60 M NH I. Start by writing the equation for the predominant equilibrium reaction. (5 marks)

38 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 8 / Calculate the ph of a 0.5 M solution of the salt ammonium bromide. Begin by writing the equation for the predominant equilibrium. (5 marks) 5. The following three solutions are mixed in a fourth container, what ph results? ( marks) 5. Complete the following equilibrium, then predict whether the reactants or products will be favoured and explain why. ( marks) Equilibrium equation - - HSO +HSO Reactants or products favoured? Explanation:

39 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 9 / Calculate the initial concentration of a KF salt solution that has a ph of 6.5. Begin by writing the equation for the predominant equilibrium reaction. (5 marks) 56. In three separate trials, ml samples of HSO were titrated with 0.0 M NaOH and the results are as below. Calculate the concentration of the HSO. ( marks) 57. A Solution of Sr OH (aq) is titrated with HSO. Explain what will happen to the electrical conductivity during the titration. Begin by writing the balanced formula equation, including states, to support your answer. ( marks) Balanced formula equation Explanation 58. Aniline C6H5NH is a weak base with a K =.x10 b -10. Calculate the concentration of an aniline solution that has a ph of Begin by writing the equation for the predominant equilibrium. (5 marks)

40 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 0 / Calculate the OH that results when ml of M HCl is mixed with Assume no volume change on mixing. ( marks) g Sr OH 60. For the reactant pair KHCO and NaHPO, write the net ionic equation for the predominant equilibrium reaction that will be established. Predict whether the equilibrium will favour reactants or products and explain why. ( marks) Equilibrium Reactants or products favoured? Explanation

41 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / 69 Multiple Choice Questions Answer Key 1 D 1 C 1 A 61 C 81 C D B D 6 C 8 D C B D 6 B 8 B B D B 6 C 8 A 5 C 5 C 5 A 65 B 85 B 6 C 6 D 6 C 66 A 86 B 7 C 7 D 7 C 67 C 87 B 8 D 8 A 8 B 68 B 88 A 9 C 9 C 9 B 69 C 89 A 10 A 0 B 50 A 70 B 90 D 11 D 1 C 51 B 71 B 91 A 1 C D 5 C 7 D 9 B 1 B B 5 D 7 D 9 C 1 A D 5 A 7 D 9 B 15 D 5 B 55 A 75 A 95 C 16 A 6 B 56 B 76 A 96 D 17 C 7 A 57 C 77 D 97 A 18 D 8 B 58 D 78 C 98 C 19 B 9 B 59 B 79 D 99 D 0 A 0 D 60 D 80 A 100 D

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