Acids and Bases Review Worksheet II Date / / Period. Molarity. moles L. Normality [H 3 O +1 ] [OH -1 ] ph poh

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1 Honors Chemistry Name Acids and Bases Review Worksheet II Date / / Period Solute Name of Solute Molar Mass grams mole Molarity moles L Normality [H 3 O +1 ] [OH ] ph poh Acidic or Basic 1. HCl Hydrochloric Acid x x Acidic 2. NaOH Sodium x M Basic 3. HClO 4 Perchloric acid x x x x Acidic 4. HNO 3 Nitric Acid x Acidic 5. RbOH Rubidium x x x x Basic 6. HI Hydroiodic Acid x Acidic 7. HNO 3 Nitric Acid x x x x Acidic 8. KOH Potassium x x Basic 9. Sr(OH) 2 Strontium x x x x Basic

2 10. Shown below is a chart of acids, their conjugate bases, and their Ka and Kb values. Fill in the missing information. (K a x K b = K w = 1 x 10 4 ) K a Acid Base K b Strong acid HNO 3, HI, HCl, etc. NO 3, I, Cl, etc. Negligible basicity 1.3 x 10-2 HSO 4 SO x x 10-4 HNO 2 NO x x 10-4 HF F 1.5 x x 10-5 CH 3 COOH CH 3 COO 5.6 x x 10-7 H 2 CO 3 HCO x x 10-8 H 2 S HS 1 x x 10 0 NH 4 +1 NH x x 10 0 HCN CN 1.6 x x 10 1 HCO 3 CO x x 10 7 HS S -2 1 x 10 3 Negligible acidity Li +1, Na +1, Ca +2, etc. O -2, OH Strong base

3 Salts are ionic compounds, which dissociate in water to produce ions. They are formed in a neutralization reaction between acids and bases. Depending on the nature of the acids and bases (strong or weak), the solutions of the salts will be acidic, basic, or neutral. 11. Determine which of the following salts will form acidic, basic or neutral solutions when dissolved in water. (Hint: look at the acids and bases that formed them) For example: KCH 3 COO was formed in the reaction between KOH and CH 3 COOH KOH is a strong base. Its conjugate acid, K +1, has negligible acidity and will leave the ph at 7.00, a neutral solution. CH 3 COOH is a weak acid, making its conjugate base, CH 3 COO a relatively strong base. It will produce a basic solution. Analyze the following salts in the same way. a. KF basic salt d. KCN basic salt WCA SCB WCA SCB (KOH SB, HF WA) (KOH SB, HCN WA) b. NaNO 3 neutral salt e. RbI neutral salt WCA WCB WCA WCB (NaOH SB, HNO 3 SA) (RbOH SB, HI SA) c. NH 4 NO 3 acidic salt f. Na 2 CO 3 basic salt SCA WCB WCA SCB (NH 3 WB, HNO 3 SA) (NaOH SB, H 2 CO 3 WA) True and False 12. The larger the value of Ka, the stronger the acid. (True) 13. The stronger an acid, the stronger its conjugate base. (False) 14. The strongest acid that can exist in aqueous solutions is perchloric acid. (False) 15. The strongest base that can exist in aqueous solutions is the OH ion. (True) 16. A solution with a ph of 13 would be acidic. (False) 17. A solution with a poh of 12 would be basic. (False) 18. The hydrogen ion concentration in a solution with a ph of 5.65 is ten times that of one with a ph of (True) Choose the correct word 19. The greater the degree of dissociation, the (stronger, weaker) the acid. 20. Acids, bases, and salts are (electrolytes, nonelectrolytes). 21. CH 3 COOH is a(n) (acid, base, salt). 22. NH 4 Cl is a(n) (acid, base, salt).

4 23. The stronger the acid, the (weaker, stronger) the conjugate base. 24. ph values (can, cannot) go off the 04 ph scale. 25. Buffers maintain a(n) (definite, indefinite) ph. 26. A ph of 2 is (100, 10, 2) times (more, less) acidic than a ph of Because a bicarbonate ion, HCO 3, can both donate and accept a proton under certain conditions it is said to be a(n) (Arrhenius, amphiprotic) species. 28. Determine the ph and poh of each of the following solutions and indicate whether each is acidic, basic, or neutral. a. Milk, [H 3 O +1 ] = 3.2 x 10-7 M (ph = 6.49, poh = 7.51, Acidic) b. Pickle Juice, [H 3 O +1 ] = 2.0 x 10-4 M (ph = 3.70, poh = 10.30, Acidic) c. Beer, [H 3 O +1 ] = 3.2 x 10-5 M (ph = 4.49, poh = 9.51, Acidic) d. Blood, [H 3 O +1 ] = 4.0 x 10-8 M (ph = 7.40, poh = 6.60, essentially neutral) 29. Determine the [H 3 O +1 ] and [OH ] of each of the following solutions, and indicate whether each is acidic, basic, or neutral. a. Lime Juice, ph = 1.9 ([H 3 O +1 ] = 1 x 10-2, [OH ] = 1 x 10 2, Acidic) b. Tomato juice, ph = 4.2 ([H 3 O +1 ] = 6 x 10-5, [OH ] = 2 x 10 0, Acidic) c. Saliva, ph = 7.0 ([H 3 O +1 ] = 1 x 10-7, [OH ] = 1 x 10-7, Neutral) d. Kitchen cleanser, ph = 9.3 ([H 3 O +1 ] = 5 x 10 0, [OH ] = 2 x 10-5, Basic) 30. Predict the characteristic of the solutions of the following salts. a. CrBr 3 (acidic) c. NaCl (neutral) b. NH 4 ClO 4 (acidic) d. K 2 CO 3 (basic) 31. The K a values for HPO 4-2 and HSO 3 are 4.8 x 10 3 and 6.3 x 10-8 respectively. Therefore it follows the HPO 4-2 is a weaker acid than HSO 3 and PO 4-3 is a stronger base than SO Given the following K a values, determine which species is the strongest base. HSO x 10-2 H 2 PO x 10-8 HCO x Given the following K a values, determine which species is the strongest base. HF 6.8 x 10-4 HNO x 10-4 HCNO 2.2 x Consider the following salts. Which one(s) when dissolved in water will produce a neutral solution? 1) CaCl 2 2) Sr(NO 3 ) 2 3) K 2 CO Consider the following salts. Which one(s) when dissolved in water will produce a basic solution? 1. RbClO 4 2. NaNO 2 3. NH 4 Cl

5 36. Consider the following salts. Which one(s) when dissolved in water will produce a neutral solution? 1. CoBr 2 2. (NH 4 ) 2 S 3. RbI 37. The ph of a solution of Ba(OH) 2 is What is the molarity of this Ba(OH) 2 solution? [H 3 O +1 ] = 10 ( 9.40) = 4.0 x 10 0 M H 3 O +1 [OH ] = 1.0 x 10 4 / 4.0 x 10 0 = 2.5 x 10-5 M OH 2.5 x 10-5 mole OH 1 mole Ba(OH) 2 = 1.3 x 10-5 M Ba(OH) 2 1 L 2 mole OH 38. Calculate the HCN (aq) + H 2 O ( ) H 3 O +1 (aq) + (CN) (aq) I 0.50 M 0 0 x + x + x E 0.50 M x x x K a = [H 3 O +1 ][CN ] = [x][x] Assume [HCN] = 0.50 M x 0.50 M [HCN] [0.50 x] 4.9 x 10 0 = x M a. [H 3 O +1 ] x = 1.6 x 10-5 M = [H 3 O +1 ] = [CN ] b. ph ph = log [1.6 x 10-5 ] = 4.80 c. percent dissociation for a 0.50 M HCN solution. (K a = 4.9 x 10 0 ) 1.6 x 10-5 M x 100 = % 0.50 M

6 39. Calculate the ph of a 0.10 M solution of aqueous ammonia, K b = 1.8 x 10-5 NH 3(aq) + H 2 O ( ) NH 4 +1 (aq) + (OH) (aq) I 0.10 M 0 0 x + x +x E 0.10 M x x x K b = [NH +1 4 ][ (OH) ] = [x][x] Assume [NH 3 ] = 0.10 M x = 0.10 M [NH 3 ] [0.10 M x] K b = 1.8 x 10-5 = x M x = [NH 4 +1 ] = [(OH) ] = M poh = -log(0.0013) = 2.89 ph = = Suppose that ml of 0.10 M CH 3 COOH is neutralized by ml of 0.10 M NaOH. What is the ph of the resulting system? a. Write the neutralization reaction. HC 2 H 3 O 2(aq) + NaOH (aq) Na +1 (aq) + (C 2 H 3 O 2 ) (aq) + HOH ( ) b. How many moles of CH 3 COO are formed? L HC 2 H 3 O mole HC 2 H 3 O 2 1 mole (C 2 H 3 O 2 ) = mole (C 2 H 3 O 2 ) 1 L 1 mole HC 2 H 3 O L NaOH 0.10 mole NaOH 1 mole (C 2 H 3 O 2 ) = mole (C 2 H 3 O 2 ) 1 L 1 mole NaOH c. What is the final volume of the solution? ml ml = ml = L solution d. What is the concentration of CH 3 COO? mole (C 2 H 3 O 2 ) = M (C 2 H 3 O 2 ) L solution

7 e. Characterize CH 3 COO (i.e. weak/strong and acid/base). (C 2 H 3 O 2 ) is a SCB because H(C 2 H 3 O 2 ) is a weak acid that it would have come from. f. Write the reaction of the product and water. (C 2 H 3 O 2 ) (aq) + H 2 O ( ) H(C 2 H 3 O 2 ) (aq) + (OH) (aq) g. Set-up an ICE chart for the reaction and calculate the ph of the solution. (C 2 H 3 O 2 ) (aq) + H 2 O ( ) H(C 2 H 3 O 2 ) (aq) + (OH) (aq) I M 0 0 x + x + x E M x x x Kb = [H(C 2 H 3 O 2 )][ (OH) ] = [x][x] Assume [(C 2 H 3 O 2 ) ] = M x [(C 2 H 3 O 2 ) ] [ M x] 5.6 x 10 0 = x M x = [H(C 2 H 3 O 2 )] = [(OH) ] = 1.7 x 10-6 M poh = log (1.7 x 10-6 M) = 5.77 ph = = 8.23