Question

1. The following pictures represent solution at various points in the titration of a weak acid with a strong base. HA + OH - HOH + A OH - -OH Which picture to the left corresponds to cach of the following points in the titration? before the addition of any NaOH at the equivalence point where only a salt remains which solution is a buffer? Multiple Choice 1. Barium hydroxide is slightly soluble in water, with a Kap of 5.00 x 10 at 298 K. The dissolution of barium hydroxide in water is an endothermic process. Which of the following will increase the solubility? Heat + Ba(OH)2 (s) 4 Ba(aq) + 2 OH(aq) A) Barium nitrate is added to the solution, Ba? B) Sodium hydroxide is added to the solution C) The temperature is increased. D) All of the above 2. Which is the best acid to use in the preparation of a buffer with pH = 4.2? A) HOI B) HNO; K= 2.0 x 10-11 K = 4.5 x 104 C) HNO, D) HIO, K. >> 1 K =1.7 x 10-1 Use the following graph to answer questions 3-6. 160.0 400 800 120.0 mL of 0.100 M NaOH added 3. The pk of this weak acid is about A. B. 5.0 10.0 C. D. 3.8 11.0 4. The pKof this weak acid is about C. 3.8 D. 11.0 4. 5.0 5. The 2nd equivalence point of this acid occurs at approximately C 80 mL D. 100 ml A. 40 mL B. 60 mL 6. A buffer will occur at which points on the graph?

Answer 1

before the addition of any noot b. 9 at the equivalence point. c. * Where only salt remains. d. € which solution is buffy 0 Answer: () The temperature is increased By increasing temperaken solubility increase, at equilibrium.. @ Angwa = B) HNO if ph= pla buffer Capacity is maximum. So that, the are which is having pha close to desired pH is best suitable pta of Halog = -log (4.5X104 )= 3.36. © Answers @.5.0 & secand equivalence point at I fpleas Tu @ Anguig - ®.90 fiost equivalerile point . (In the graph it is at 10.) I Answer: © some @ Answer: ® At pH = pka, and pH= pkar. ② answers ② Weale aid and strong base T® Ansung; ②. 5. @ Anscost ® 1:3x103 V plant + Vol. NAOH WN newen HONt kott & H2O tken