d. 4.95 e. 2.85 15. the pAg during the titration of 50.0 ml of 0.040 M NaCl with 20 ml of 0.100 AgNO3 (Ksp for AgCl = 1.82×10-10) a. 4.87 b. 3.87 c. 2.76 16. 100 ml of city drinking water was buffered at pH 10. after addition of indicator the solution needed 15.46 ml of 5.140×10 MEDTA for titration. the hardness of water in terms of ppm of CaCO, is .(MW of CaCO, is 100.08 g/mlo) b. 79.5 ppm a. 110.4 ppm d. 112.3 ppm e. 283.3 ppm c. 114.33ppm 17. A 50.0-mL sample containing Ni²+ was treated with 25.0 mL of 0.0500 M EDTA to complex all the Ni2 and leave excess EDTA in solution. The excess EDTA was then back-titrated, requiring 5.00 mL of 0.0500 M Zn². What was the concentration of Ni²+ in the original solution? b. 4.0×10 M a. 2.0 × 10 M c. 2.1 × 10-M d.5.23 ×104 M e. none of these 18. The ApH for 20.0 mL of 0.1750 M formic acid solution (weak acid ka = 1.8x104) after it diluted with 45.0 mL of distilled water (the final volume of the acid is 65 ml ). a. 0.25 b. 0.35 c. 0.48 d. 1.78 e.2.35 19. The molarity of a 22.75% HCI solution. The density of this solution is 1.13 g/mL, and the molar mass of HCI is 36.46 g/mol. a. 26.7 M c. 3.75 M d. 7.05 M e. 12.1 M b.31.0 M 20. 25.0 mL of NaCl unknown concentration was titrated against 23.0 mL of 0.009 M AgNO3. Calculate the ppm of NaCl in the original sample. (Na-23 g/mol, Cl- 35.5 g/mol) d. 29.39ppm. e 950ppm a. 484.38ppm b. 293.94ppm c. 48.44ppm 21. 100 ml of city drinking water was buffered at pH 10. after addition of indicator the solution needed 21.46 ml of 5.140x10-3 M EDTA for titration, the hardness of water in terms of ppm of CaCO3 is. (MW of CaCO3 is 100.08 g/mlo) a) 110.4 ppm d. 234.45 pp b) 1104.04 ppm c) 114.33ppm e) never of theses 22. The pH of of 0.1 00M NaHCO, solution is (the dissociation constants for H₂CO3 is kal = 4.45 × 107 and Ka2 =4.69 × 10-¹¹) a)8.33 b) 8.6 3 c) 9.8 d) 10.67 23. A silver nitrate solution contains 14.77 g of primary-standard AgNO3 (169.87 g/mol) in 1.00 L. What volume of this solution will be needed to react completely with 0.2631 g of NaCl (58.44 g/mol)? a)51.78 ml. c) 0.543 ml b) 0.05231 L d) 53.657 ml e. 26.36 ml e.5.3