Acids, Bases, & Neutralization Chapter 20 & 21 Assignment & Problem Set

Transcription

1 Acids, Bases, & Neutralization Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8.

2 Acids, Bases, & Neutralization 2 Study Guide: Things You Must Know Vocabulary (know the definition and what it means): strong and weak electrolyte binary acid polyatomic acid acid and base self-ionization of water hydrogen ion, hydronium ion, proton, and hydroxide ion ion product constant for water ph indicator dye Arrhenius acid and Arrhenius base Bronsted-Lowry acid and base conjugate acid-base pair acid and base strength mono-, di-, and tri-protic acid acid and base ionization neutralization salt titration equivalence point (end point) Honors: hydrolysis Learning Objectives: properties of acids and bases how to name acids using the three rules based on the anion name. how to write the equilibrium for the self-ionization of water how to calculate either the hydrogen ion or hydroxide ion concentrations using K w. how to tell whether an aqueous solution is acidic or basic given either the hydrogen ion or hydroxide ion concentration. how to calculate ph given the hydrogen ion or hydroxide ion concentrations. how to calculate the hydrogen ion or hydroxide ion concentrations given ph. how to interpret the ph scale. by what factor the hydrogen ion concentration changes when ph changes. how ph is measured using indicator dyes and/or a ph meter. Arrhenius theory of acids and bases. Bronsted-Lowry theory of acids and bases. how to write equilibrium reactions for the addition of acids or bases to water. how to determine acid-base conjugate pairs. strong and weak acids and bases. the difference between strength and concentration. how to write balanced equations for acid-base neutralization reactions. how to solve titration problems using stoichiometry. Honors: How to determine whether a salt is acidic or basic based on hydrolysis. Key Reference Tables Table E: Selected Polyatomic Ions Table K: Common Acids Table L: Common Bases Table M: Common Acid-Base Indicators

3 Acids, Bases, & Neutralization 3 Read Chapter 20: Acids and Bases, except all students skip Lewis Acids and Bases, p598, and Calculating Dissociation Constants, pp Read Chapter 21 Neutralization except all students skip Equivalents & Normality pp , Buffers pp , and Solubility Product Constant pp Lab 21: Measuring ph Lab 22: Titration of a Strong and Strong Base Lab 23: Neutralization Reaction Regents Tables Table F: Solubility guidelines Table K: Common Acids Table L: Common Bases Table M: Common Acid-Base Indicators Table T: Important Formulas and Equations Extra credit: (due anytime before you take the test date) Write a short report on how acids and bases are important in our everyday lives. Your report could focus on a single example or list multiple examples. The structure and names of the acids and bases used in your report should be given, as well as pertinent chemical equations. Possible topics include, but are not limited to, biology, food, medicine, industrial processes, and water purification. The report length must be a single typed page for 10 extra credit points or two typed pages for 20 extra credit points (11 point font, double-spaced, one inch margins, and include references). Warm-ups and problems will be collected before you take the test. Answer all problems in the space provided. For problems involving an equation, carry out the following steps: 1. Write the equation. 2. Substitute numbers and units. 3. Show the final answer with units. There is no credit without showing work. Naming and Properties of Naming Acids and Bases 1. Identify each property as applying to an acid, a base, or both. a. bitter taste b. electrolyte c. indicator color change d. sour taste 2. Write the formula for each acid or base. a. barium hydroxide c. rubidium hydroxide b. hydrobromic acid d. hydroselenic acid 3. Name each acid or base. a. HF c. H 2CO 3 b. HClO 3 d. Al(OH) 3 4. Write the formulas for these compounds. a. nitrous acid c. phosphoric acid b. aluminum hydroxide d. ethanoic acid

4 Acids, Bases, & Neutralization 4 5. If given the name, write the formula; if given the formula, write the name. a. HNO 2 c. Sulfuric acid b. HI d. HC 2H 3O 2 Hydrogen Ion and Hydroxide Ion Concentrations 6. Write an equation showing the self-ionization of water. 7. What are the concentrations of H + and OH - in pure water at 25 o C. 8. What is the ion product for water, and what does it mean? 9. What is true about the relative concentrations of hydrogen ions and hydroxide ions in each kind of solution? a. basic b. acidic c. neutral 10. Classify each solution as acidic, basic, or neutral. a. [H + ] = 6.0 x M c. [H + ] = 2.0 x 10-7 M b. [OH - ] = 3.0 x 10-2 M d. [OH - ] = 1.0 x 10-7 M Understanding ph 11. By what factor does the hydrogen ion concentration change if the ph changes from 3.0 to 5.0? Does it increase or decrease? 12. What are the ph values of the following three solutions based on their hydrogen ion concentration? a. [H + ] = 1.0 x M b. [H + ] = 0.010M c. [H + ] = 1.0 x 10-4 M 13. Honors Calculate the ph of each solution. a. [H + ] = 5.0 x 10-6 M b. [H + ] = 2.7 x 10-7 M c. [H + ] = 8.3 x M 14. What are the hydrogen ion concentrations for solutions with the following ph values? a. 4.0 b c. 8.0

5 Acids, Bases, & Neutralization Honors What is the molarity of [H + ] in each solution. a. ph = 7.30 b. ph = 1.80 Combining ph, [H + ], and [OH - ] 16. Describe, using equations, how to calculate ph given [OH - ]. 17. Calculate the ph for the following solutions, and indicate whether each solution is acidic (A) or basic (B). a. [H + ] = 1.0 x 10-2 M c. [OH - ] = 1.0 x 10-8 M b. [OH - ] = 1.0 x 10-2 M d. [H + ] = 1.0 x 10-6 M 18. Calculate the ph and state whether the solution is acidic (A) or basic (B). a. [H + ] = 1.0 x 10-4 M c. Honors [H + ] = 6.2 x 10-4 M b. [OH - ] = 1.0 x 10-8 M d. Honors [OH - ] = 1.7 x 10-8 M 19. What are the hydroxide-ion concentrations for solutions with the following ph values. a b c Honors A soft drink has a ph of What is the hydrogen ion concentration of the drink? 21. Calculate [OH - ] a. if ph is 9.0 b. Honors if ph is Calculate the ph of each solution. a. [OH - ] = 1.0 x 10-5 M b. Honors [OH - ] = 4.5 x M Measuring ph and Indicator Dyes 23. If a few drops methyl orange are placed into an aqueous solution and the solution turns yellow, what do you know about the ph?

6 Acids, Bases, & Neutralization Over what range of ph will bromcresol green appear green? Acid-Base Theories 25. Classify each as an Arrhenius acid or an Arrhenius base. a. Ca(OH) 2 c. KOH e. HBr b. HNO 3 d. C 2H 5COOH f. H 2SO Identify the acid, base, conjugate acid and conjugate base in the following equations. a. HNO 3 + H 2O H 3O + + NO 3 - b. CH 3COOH + H 2O H 3O + + CH 3COO - c. H 2O + HF F - + H 3O + d. NH H 2O NH 3 + H 3O Identify each compound as a strong or weak acid or base. a. NaOH c. HCl b. NH 3 d. H 2SO Write equations for the reaction of each substance with water. For each equation, identify the hydrogen ion donor and hydrogen ion acceptor. Then label the conjugate acid-base pairs in each equation. a. HNO 3 b. CO Classify each acid as monoprotic, diprotic, or triprotic (be careful!). a. HCOOH b. H 3PO 4 c. HBr

7 Acids, Bases, & Neutralization For each solution below, state whether it is a strong or weak acid, and whether it is a concentrated or dilute acid. Strong (S) or Weak (W) Conc.(C) or Dilute (D) a. 2.2 M H 2SO 4 b M HC 2H 3O 2 c. 1.3 x 10-3 M HCl d. 6.0 M H 2CO 3 Acid-Base Neutralization 31. What class of reaction is acid-base neutralization? 32. Define salt. 33. Write balanced equations for these acid-base reactions. Give the names of the salts produced. a. H 2SO 4(aq) + KOH(aq) b. HCl(aq) + LiOH(aq) c. HCl(aq) + Ca(OH) 2(aq) d. Phosphoric acid and calcium hydroxide solution e. Nitric acid and magnesium hydroxide solution 34. What acid and base need to be mixed to form the salt calcium fluoride. Write a balanced equation.

8 Acids, Bases, & Neutralization 8 Titration 35. Write a balanced chemical equation for the reaction of sodium hydroxide and nitric acid. How many moles of sodium hydroxide are required to neutralize 0.20 mol of nitric acid? 36. Write a balanced chemical equation for the reaction of potassium hydroxide and phosphoric acid. How many moles of potassium hydroxide are needed to completely neutralize 1.56 mol of phosphoric acid? 37. How many moles of hydrochloric acid are required to neutralize aqueous solutions of these bases? a. 0.2 mol NH 3 b. b. 0.1 mol Ca(OH) What is characteristic of the end point of a titration? 39. How many milliliters of 0.45 M hydrochloric acid must be added to 25.0 ml of 1.00M potassium hydroxide to make a neutral solution? First write a balanced equation. 40. What is the concentration of an aqueous solution of Ba(OH) 2 if 27 ml of this solution is titrated to the equivalence point with 51 ml of 0.82 M HCl? First write a balanced equation. 41. What is the molarity (M) of sodium hydroxide if 20.0 ml of the solution is neutralized by 17.4 ml of 2.00 M H 3PO 4 solution?

9 Acids, Bases, & Neutralization 9 Salt Hydrolysis 42. Honors What kinds of salts hydrolyze in water? 43. Honors Write an equation showing why an aqueous solution of sodium hydrogen carbonate is basic. 44. Honors Predict whether an aqueous solution of each salt will be acidic, basic, or neutral. a. NaHCO 3 d. KCl g. Na 2SO 4 b. NH 4NO 3 e. Na 2CO 3 h. NH 4Cl c. NaF f. Ca(C 2H 3O 2) 2 Review 45. Honors An impure sample of AgNO 3 weighing g was dissolved in water. After the addition of excess HCl, 0.213g AgCl was recovered. Write a chemical equation for the reaction, and calculate the percentage of AgNO 3 in the sample. 46. In each pair, which has the higher entropy? Explain. a. NaCl(s) or NaCl(aq) b. CO 2(s) or CO 2(g) c. H 2O(l) at 60 o C or H 2O(l) at 25 o C? 47. How many grams of NaOH are in 200 ml of 0.12 M NaOH?

10 Acids, Bases, & Neutralization Write formulas for the following substances. a. iron(iii) chloride b. tin(ii) carbonate c. magnesium chromate d. ammonium bromide 53. How would you prepare ml of a 0.680M KOH solution? 54. How would each change affect the position of equilibrium of this reaction: 2H 2(g) + O 2(g) 2H 2O(g) + heat e. increasing the pressure f. adding a catalyst g. increasing the concentration of H 2(g) h. cooling the reaction mixture i. removing water vapor from the container 55. Define vapor pressure. What is the vapor pressure of water at 78 o C?