b. H 2 SO 4!! d. KOH!! f. HCl!

Chemistry L3 Name Page 1 Worksheet: Acids and Bases (Chapter 20, p. 576) 1. Classify these as an Arrhenius acid ( starts with H + ) or Arrhenius base (ends in OH ). Then name each one. (p 577-579, 594-596) a. Ca(OH) 2! c. HNO 3!! e. HC 2 H 3 O 2! b. H 2 SO 4!! d. KOH!! f. HCl! 2. Complete the equations for the Ionization of these Arrhenius acids or bases in water: ex: HBr + H 2 O > H 3 O + + Br! or! KOH > K + + OH a. HNO 3 + H 2 O >! c. NaOH > b. HCl + H 2 O >! d. Ca(OH) 2 > 3. Identify the following as either Bronsted-Lowry acids (loses an H + ion) or bases (gains an H + ion). Then identify the conjugate acid and the conjugate base. (p. 596-598) Example: HCl + H 2 O ---> Cl + H 3 O +!! HCl lost an H + to become Cl -! acid! base! conj base! conj acid! H 2 O gained an H + to become H 3 O + a. HNO 3 + H 2 O ---> H 3 O + + NO 3! e. NH 3 + H 2 O <---> NH 4 + + OH b. H 2 SO 4 + OH ---> HSO 4 + H 2 O! f. C 2 H 3 O 2 + H 2 O <---> OH + HC 2 H 3 O 2 c. H 2 PO 4 + OH <---> HPO 4 2 + H 2 O! g. H 2 PO 4 + H 3 O + <---> H 3 PO 4 + H 2 O d. HCO 3 + H 2 O <---> H 3 O + + CO 3 2! h. HCO 3 + H 2 O <---> H 2 CO 3 + OH 4. What is the conjugate acid of the following: (particle made by adding an H + ion) ex. NO 3! HNO 3! b. C 2 H 3 O 2!! d. CO 2 3! a. Cl!! c. HCO 3!! e. H 2 PO 4! 5. What is the conjugate base of the following: (particle made by removing an H + ion) ex. HBr! Br! b. NH 4+!! d. H 2 CO 3! a. H 2 O!! c. HCO 3!! e. H 2 PO 4! 5f. What does 4c and 5c tell you about HCO 3? (hint: p. 598)

6. Identify the following as Weak acids, Strong acids, Weak bases or Strong bases:! Page 2 a. HCl! NaOH! HC 2 H 3 O 2! H 2 SO 4! Formic acid, HCHO 2 b. H 2 CO 3! NH 4 OH! Ca(OH) 2! Citric acid H 3 PO 4 7. Rank these acids from strongest (1) to weakest (6) using the following table.! (The larger the K a the stronger the acid.) (p. 600-604)! Which Picture of Particles (A, B, C) best represents each? A! Name! Formula! K a! Rank! Picture? a. Formic acid! HCHO 2! 1.8 x 10 4!! b. Oxalic acid! H 2 C 2 O 4! 5.6 x 10 2!! c. Benzoic acid! HC 6 H 5 CO 2! 6.3 x 10 5!!! d. Nitric acid! HNO 3! Strong!!! e. Carbonic acid! H 2 CO 3! 4.3 x 10 7!! B f. Acetic acid! HC 2 H 3 O 2! 1.8 x 10 5!!! 8. a. Which acid from #7 is the strongest weakest?! b. Has the Lowest ph Highest ph! c. Is the Most acidic Least acidic! d. Would have the highest [H + ] (concentration of H + ions)! Would have the highest [OH ] (concentration of OH ions) 9. Which of the following household products would you predict to be acidic? Which would be basic? Neutral? a. Vinegar! b. Ivory soap! c. Cola d. Dishwasher detergent! e. Orange juice! f. Tums Antacid g. Gatorade! h. Windex with ammonia! i. Draino Ans from front: 1a. B, Calcium Hydroxide; b. Sulfuric acid; c. Nitric acid; d. B, potassium hydroxide; e. Acetic acid; f. Hydrochloric acid; HNO 3 + H 2O > H 3O + +NO 3 ; b. HCl + H 2O > H 3O + + Cl ; c. NaOH >Na + +OH ;d. Ca(OH) 2 > Ca +2 +2OH ; 3a. A, B, CA, CB; b. A, B, CB, CA; c. A, B, CB, CA; d. A, B, CA, CB; e. B, A, CA, CB; f. B, A, CB, CA; g. B, A, CA, CB; h. B, A, CA, CB; 4. a. HCl; b. HC 2H 3O 2 ; c. H 2CO 3 ; d. HCO 3 ; e. H 3PO 4 ; 5a. OH ; b. NH 3 ; c. CO 3 2 ; d. HCO 3 ; e. HPO 4 2 ; f. amphoteric, can be acid or base; Ans to Page 2: 6. a. SA, SB, WA, SA, WA, b. WA, WB, SB, WA, WA ; 7. Rank: 3, 2, 4, 1, 6, 5; Pic: B, B, B, A, C, B; 8a. HNO 3, H 2 CO 3 ; b, c, and d are same as a ; 9. Acids = a, c, e, g, Bases = b, d, f, h, i Ans to Page 3: 1. No, all change color at different ph s; 2. No, Br Blue is blue for ph 7 to 13; 3. No, Need to know with which indicator; 4. ph 1, ph 5 (light green) or ph 6 (Dark green), ph 11; 5. Can t tell, lots of yellows, need to know with which indicator; 6. Indigo carmine, yellow= ph 13; 8B. ph 4, peach with Methyl yellow; C. ph 9, peach with Neutral Red; D ph 13, Yellow with Indigo carmine; 9. Indigo carmine, only yellow at very basic ph 13; 10. Neutral Red, Red at ph 7; 11. Methyl Violet is green at ph 1, very acidic. CHART: ph 1=Green in M. Violet, ph 2=Blue in M. Violet; ph 3=Orange in Methyl Yellow; ph 4=Peach in M. Yellow; ph 5=Lt Green in Bromo Green; ph 6=Green in Br. Green; ph 7=Red in Neutral Red; ph 8= Pink in Neut Red; ph 9=Peach in Neut Red; ph 10=light Blue in Indigo carmine; ph 11=green in Ind. Carm; ph 13 = yellow in Ind. Carm. C

Pre Lab Practice : Examine the Practice ph color guide. The names on the left are called Page 3 Indicators. They change color at certain ph s. This can help chemists identify the ph of materials. 1. Do all the indicators change color at the same ph s? Yes or No? 2. A solution turns Blue in Bromo Green. Is this enough information to identify a specific ph for this solution? Explain. 3. A solution turns Green when you add an indicator. Is this enough information to identify a specific ph? Yes or No 4. What is the ph of a solution that turns green in Methyl violet? Green in Bromo Green? Light Greenish in Indigo carmine? 5. A solution turns yellow when an indicator is added. Is this solution acidic, basic, or neutral? What more information do you need to answer this question? 6. What is the only indicator which has yellow as a key color? What ph is it? 7. Fill in the following chart. Identify the Key Color with which Indicator for each ph. ph Key color Indicator ph Key color Indicator 1 Green Methyl Violet 7 2 8 3 9 4 10 5 11 6 13 8. Use your Key Color chart above to determine the ph of the Practice ph Household Items. What Key color with which Indicator identifies the ph? Solution A : ph = 8 Key color Pink With Indicator = Neutral Red! Solution B: ph = Key color With Indicator =! Solution C: ph = Key color With Indicator =! Solution D: ph = Key color With Indicator = 9. Which one indicator could you use to determine if a solution is very basic? Indicator = with Key color(s) 10. Which one indicator will tell you if a solution is neutral? Indicator = with Key color 11. Which one indicator could you use to determine if a solution is very acidic? Indicator = with Key color(s)

ph Calculations : Get a Calculator with a Log key!!!! Page 4 ph = log [H + ] poh = log [OH ] In water solution: ph = 14 poh 1. Calculate the ph of the following solutions. (Concentrations are given in Molarity). a. [H + ] = 1.0 x 10 5! b. [H + ] = 1.0 x 10 9! c. [H + ] = 0.10! d. [H + ] = 0.0010! e. poh = 13.00! f. poh = 5.10! g. [OH ] = 1.0 x 10 11! h. [OH ] = 1.0 x 10 4 i. [OH ] = 0.000010! j. [H + ] = 3.0 x 10 5! k. [H + ] = 4.5 x 10 8! l. [H + ] = 7.5 x 10 2! m. [OH ] = 5.0 x 10 5! n. [OH ] = 4.0 x 10 13 For the following problems:! [H + ] = 10 ph! [OH ] = 10 poh! [H + ] = 1 x 10 14! (Notice: 10 raised to the ph power! NOT 10 minus ph)! [OH ] 2. Calculate the [H + ] of the following. (answers given in Molarity)! a. ph = 13.00! b. ph = 9.00! c. poh = 6.00! d. poh = 2!.00 e. [OH ] = 1.0 x 10 5! f. [OH ] = 4.0 x 10 7! g. [OH ] = 2.0 x 10 5 h. ph = 4.30! i. ph = 10.52! j. poh = 1.40! k. poh = 10.90! 3. Calculate the poh of the following. poh = log [OH ]! poh = 14 ph a. ph = 4.00! b. [OH ] = 2.0 x 10 5! c. [H + ] = 1.0 x 10 13! 4. Calculate the [OH ] of the following. [OH ] = 10 poh! (10 to the poh power) a. poh = 3.35! b. ph = 10.93! c. [H + ] = 2.5 x 10 12 1a)5.00; b)9.00; c)1.00; d)3.00; e)1.00; f)8.90; g) 3.00; h) 10.00; i) 9.00; j) 4.52; k) 7.35; l)1.12; m) 9.70; n) 1.60; 2a)1.0x10 13 ;b) 1.0x10 9 ; c)1.0x10 8 ; d) 1.0x10 12 ;e)1.0x10 9 ; f) 2.5x10 8 ; g) 5.0x10 10 ; h) 5.0 x10 5 ; i) 3.0 x10 11 ; j)2.5 x10 13 ; k)7.9 x10 4 ; 3a)10.00 ; b) 4.70 ; c)1.00 ; 4a) 4.5x10 4 ; b) 8.5 x10 4 ; c) 4.0x10 3

Chem Level 3 Acids and Bases Page 5 Weak Acid Equilibrium Calculations K a = [H + ] 2! or [H + ] = K a [HA] (p. 604-605) For a weak acid HA which slightly ionizes:! [HA] [HA] is the Weak acid concentration in Molarity! 1. K a of a weak acid is 1.0 x 10 7. Calculate the [H + ] and ph of a 0.10 M (1.0 x 10 1 M) solution of this acid.! (1.0 x10 4 M, 4.00) 2. a. Calculate the [H + ] of a 0.50 M solution of Acetic acid (K a = 1.8 x 10 5 ).! (3.0x10 3 M) b. Calculate the ph of this solution.! (2.52) 3. The [H + ] is 1.0 x 10 4 M in a 0.20 M solution of a weak acid. a. What is the ph of this solution? b. Calculate the value for K a for this acid.! (4.00, 5.0x10 8 ) 4. The ph = 1.82 for a 0.50 M HNO 2 solution. a. Calculate the [H + ] of this solution.! (1.5x10 2 M) b. Calculate the K a for this acid.! (4.6x10 4 ) Review questions for acids and bases 1. Consider these solutions: Is each : weak or strong, acid or base a. 1 M HCl! b. 1 M HC 2 H 3 O 2! c. 1 M NH 4 OH! d. 1 M NaOH a.! b.! c.! d. Which has a ph about?! 14! 10! 3! 0 Which is very acidic! moderately acidic! very basic! moderately basic Which has the lowest [H + ]! 2. Label the acid, base, conjugate acid and conjugate base. highest [H + ]! lowest [OH ]! highest [OH ] a. HPO 4 2 + H 2 O <---> H 3 O + + PO 4 3! c. HPO 4 2 + H 2 O <---> H 2 PO 4 + OH b. NH 4 + + H 2 O <---> NH 3 + H 3 O +! d. CO 3 2 + H 3 O + <----> H 2 O + HCO 3

3. Calculate the ph of the following solutions. Is each acidic or basic? page 6 a. [H+] = 1.0 x 10-7! b. [H + ] = 0.010! c. poh = 7.3! d. poh = 2.1 e. [OH ] = 1.0 x 10 10! f. [OH ] = 3.5 x 10 2! g. [H + ] = 4.0 x 10 6! h. [H + ] = 8.0 x 10 6 4. Calculate the [H + ] of the following solutions. a. ph = 10.00! b. poh = 8.00! c. [OH ] = 1.0 x 10 6! d. ph = 5.7 e. ph = 10.10! f. poh = 5.30! g. What's the [OH ] if ph = 11.00? 5. The K a for Formic acid is 1.8 x 10 4 and the Ka for Acetic acid is 1.8 x 10 5. Which one is the stronger acid? The weaker acid? 6. What is the conjugate base of : HCl!H 2 O!HCO 3 7. What is the conjugate acid of : NO 3!H 2 O!HCO 3 8. a. Calculate the [H + ] and ph of a 0.10 M solution of benzoic acid (K a = 6.3 x 10 5 ).!(2.5 x10-3, 2.60) 9. The ph is 3.22 for a 0.25 M solution of an unknown acid. a. Calculate the [H + ] of this solution. b. Calculate the Ka for this acid.! (6.0x10 4, 1.5x10-6 ) 10. Match each substance with the most appropriate characteristic (Use each only once) a. HNO 3! A. Is a triprotic acid b. NH 3! B. Is pink in basic solutions c. H 2 PO 4! C. Is a strong acid d. H 3 PO 4! D. Is a weak base e. OH! E. Is the conjugate base of H 2 O f. Phenolpthalein! F. Is the conjugate acid of HPO 4 2 1. HCl = SA, ph 0, Very acidic, highest [H + ], lowest [OH ]; HC 2 H 3 O 2 = WA, ph 3, mod acidic; NH 4 OH = WB, ph 11, mod basic; NaOH = SB, ph 14, very basic, highest [OH ], lowest [H + ]; 2a. a, b, ca, cb; b. a, b, ca, cb; c. b, a, ca, cb; d. b, a, cb, ca; 3. a. 7.00, b. 2.00, c. 6.70, d. 11.90, e. 4.00, f. 12.54, g. 5.40, f. 5.10; 5a. 1.0 x 10 10 ; b. 1.0 x 10 6, c. 1.0 x 10 8, d. 2.0 x 10 6, e. 7.9 x 10 11, f. 2.0 x 10 9, g. 1.0 x 10 3 ; 5. Str = formic, weaker = acetic; 6. Cl, OH, CO 3 2 ; 7. HNO 3, H 3 O +, H 2 CO 3 ; 10. a=c, b=d, c=f, d=a, e=e, f=b.