Acid & Base Review. The H + acceptor for the forward reaction is A) H2O( ) B) NH3(g) 20. Given the reaction: HSO4 + HPO4 2 «SO4 2 + H2PO4

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1 1. Which compound is an electrolyte? A) B) C) D) 2. Which laboratory test result can be used to determine if KCl(s) is an electrolyte? A) ph of KCl(aq) B) ph of KCl(s) C) electrical conductivity of KCl(aq) D) electrical conductivity of KCl(s) 3. Given the equation representing a reversible reaction: NH3(g) + H2O( ) NH4 + (aq) + OH (aq) According to one acid-base theory, the reactant that donates an H + ion in the forward reaction is A) NH3(g) B) H2O( ) C) NH4 + (aq) D) OH (aq) 4. When dissolved in water, an Arrhenius base yields A) hydrogen ions B) hydronium ions C) hydroxide ions D) oxide ions 5. According to the Arrhenius theory, a base reacts with an acid to produce A) ammonia and methane B) ammonia and a salt C) water and methane D) water and a salt 6. Which compound is an Arrhenius acid? A) CaO B) HCI C) K2O D) NH3 7. When one compound dissolves in water, the only positive ion produced in the solution is H3O + (aq). This compound is classified as A) a salt B) a hydrocarbon C) an Arrhenius acid D) an Arrhenius base 8. Given the equation: HCl(g) + H2O( ) X(aq) + Cl (aq) Which ion is represented by X? A) hydroxide B) hydronium C) hypochlorite D) perchlorate 9. Which substance is an Arrhenius base? A) CH3OH B) CH3Cl C) LiOH D) LiCl 10. According to the Arrhenius theory, an acid is a substance that A) changes litmus from red to blue B) changes phenolphthalein from colorless to pink C) produces hydronium ions as the only positive ions in an aqueous solution D) produces hydroxide ions as the only negative ions in an aqueous solution 11. When the hydronium ion concentration of a solution is increased by a factor of 10, the ph value of the solution A) decreases 1 ph unit B) decreases 10 ph units C) increases 1 ph unit D) increases 10 ph units 12. A solution with a ph of 2.0 has a hydronium ion concentration ten times greater than a solution with a ph of A) 1.0 B) 0.20 C) 3.0 D) What is the ph of a M HNO3 solution? A) 1 B) 2 C) 3 D) The [H3O + ] of a solution is This solution has a ph of A) 6, which is acidic B) 8, which is basic C) 6, which is basic D) 8, which is acidic 15. The H3O + ion concentration of a solution is mole per liter. This solution is A) acidic and has a ph of 4 B) acidic and has a ph of 10 C) basic and has a ph of 4 D) basic and has a ph of Based on the results of testing colorless solutions with indicators, which solution is most acidic? A) a solution in which bromthymol blue is blue B) a solution in which bromcresol green is blue C) a solution in which phenolphthalein is pink D) a solution in which methyl orange is red 17. Which indicator would best distinguish between a solution with a ph of 3.5 and a solution with a ph of 5.5 A) bromthymol blue B) bromcresol green C) litmus D) thymol blue 18. According to one acid-base theory, a base is an A) B) C) D) 19. Given the equation representing a reaction at equilibrium: NH3(g)+ H2O( ) NH4 + (aq) + OH (aq) The H + acceptor for the forward reaction is A) H2O( ) B) NH3(g) C) NH4 + (aq) D) OH (aq) 20. Given the reaction: HSO4 + HPO4 2 «SO4 2 + H2PO4 Which pair represents an acid and its conjugate base? A) HSO4 and SO4 2 B) HSO4 and HPO4 2 C) SO4 2 and H2PO4 D) SO4 2 and HPO4 2

2 Base your answers to questions 21 and 22 on the information below and on your knowledge of chemistry. The ph of various aqueous solutions are shown in the table below. 21. State how many times greater the hydronium ion concentration in the HCl(aq) is than the hydronium ion concentration in the HC2H3O2(aq). 22. Complete the table by writing the color of thymol blue in the NaCl(aq) and in the NaOH(aq) solutions. 23. Given the reaction: H2O + HCl «H3O + + Cl The Brönsted-Lowry base for the forward reaction is A) H2O B) HCl C) H3O + D) Cl 24. Which is the conjugate acid of HSO4? A) H2SO4 B) H3O + C) HSO3 D) SO Which compound is produced when HCl(aq) is neutralized by Ca(OH)2(aq)? A) CaCl2 B) CaH2 C) HClO D) HClO2 26. Which solution reacts with LiOH(aq) to produce a salt and water? A) KCl(aq) B) CaO(aq) C) NaOH(aq) D) H2SO4(aq) 27. Which word equation represents a neutralization reaction? A) base + acid salt + water B) base + salt water + acid C) salt + acid base + water D) salt + water acid + base 28. Which equation represents a neutralization reaction? A) 4Fe(s) + 3O2(g) Fe2O3(s) B) 2H2(g) + O2(g) 2H2O( ) C) HNO3(aq) + KOH(aq) KNO3(aq) + H2O( ) D) AgNO3(aq) + KCl(aq) KNO3(aq) + AgCl(s)

3 Base your answers to questions 29 and 30 on the information below and on your knowledge of chemistry. During a laboratory activity, a student places 25.0 ml of HCl(aq) of unknown concentration into a flask. The student adds four drops of phenolphthalein to the solution in the flask. The solution is titrated with M KOH(aq) until the solution appears faint pink. The volume of KOH(aq) added is 18.5 ml. 29. Complete the equationfor the neutralization reaction that occurs during the titration. 30. Determine the concentration of the HCl(aq) solution, using the titration data. 31. Base your answer to the following question on the information below. In a titration, 20.0 milliliters of 0.15 M HCl(aq) is exactly neutralized by 18.0 milliliters of KOH(aq). Compare the number of moles of H + (aq) ions to the number of moles of OH (aq) ions in the titration mixture when the HCl(aq) is exactly neutralized by the KOH(aq). Base your answers to questions 32 through 34 on the information below. Some carbonated beverages are made by forcing carbon dioxide gas into a beverage solution. When a bottle of one kind of carbonated beverage is first opened, the beverage has a ph value of After the beverage bottle is left open for several hours, the hydronium ion concentration in the beverage solution decreases to of the original concentration. Determine the new ph of the beverage solution. 33. Using Table M, identify one indicator that is yellow in a solution that has the same ph value as this beverage. 34. State, in terms of the ph scale, why this beverage is classified as acidic.

4 Base your answers to questions 35 through 37 on the information below. In liquid water, an equilibrium exists between H2O( ) molecules, H + (aq) ions, and OH - (aq) ions. A person experiencing acid indigestion after drinking tomato juice can ingest milk of magnesia to reduce the acidity of the stomach contents. Tomato juice has a ph value of 4. Milk of magnesia, a mixture of magnesium hydroxide and water, has a ph value of What is the color of thymol blue indicator when placed in a sample of milk of magnesia? 36. Identify the negative ion found in milk of magnesia. 37. Compare the hydrogen ion concentration in tomato juice to the hydrogen ion concentration in milk of magnesia. Base your answers to questions 38 through 40 on the information below. Soil ph can affect the development of plants. For example, a hydrangea plant produces blue flowers when grown in acidic soil but pink flowers when grown in basic soil. Evergreen plants can show a yellowing of foliage, called chlorosis, when grown in soil that is too basic. Acidic soil can be neutralized by treating it with calcium hydroxide, Ca(OH)2, commonly called slaked lime. Slaked lime is slightly soluble in water. 38. Write an equation, using symbols or words, for the neutralization of the ions in acidic soil by the ions released by slaked lime in water. 39. An evergreen plant has yellowing foliage. The soil surrounding the plant is tested with methyl orange and bromthymol blue. Both indicators turn yellow in the soil tests. State, in terms of ph value, why the yellowing of the plant is not due to chlorosis. 40. Compare the hydrogen ion concentration to the hydroxide ion concentration in soil when a hydrangea plant produces pink flowers.

5 Answer Key Acid and base review 1. D 2. C 3. B 4. C 5. D 6. B 7. C 8. B 9. C 10. C 11. A 12. C 13. C 14. B 15. A 16. D 17. B 18. A 19. B 20. A A 24. A 25. A 26. D 27. A 28. C M 0.11 M 0.1 M 31. —The number of moles of H + (aq) ions equals the number of moles of OH (aq) ions. —The number of hydrogen ions is the same as the number of hydroxide ions bromthymol blue bromcresol green thymol blue 34. The beverage is acidic because its ph value is below 7. A ph of 3 is in the acid range on the ph scale. 35. blue 36. OH (aq) or OH or hydroxide ion 37. The H + ion concentration in tomato juice is 10 6 times greater. The hydrogen ion concentration in tomato juice is greater than that in milk of magnesia. Milk of magnesia has a lower concentration of H3O + ions. 38. Examples: H3O + (aq) + OH - (aq) 2H2O( ) ; H + + OH - HOH hydrogen ions + hydroxide ions water; hydroxide ions + hydronium ions water 39. Examples: The ph is between 4.4 and 6.0, which indicates an acidic soil. The ph of the soil surrounding the plant is below 6.0. For chlorosis, the soil ph must be above Examples: The hydroxide ion concentration is greater than the hydrogen ion concentration. The H3O + concentration is less than the OH - concentration. [OH - ] > [H3O + ]