Question

The following pictures represent solutions that contain a weak acid HA (pka = 5.0) and its potassium salt KA. Unshaded spheres represent H atoms and shaded spheres represent A-ions. (K, H30, OH", and solvent H2O molecules have been omitted for clarity.) -HA -A (1) 12) 12) Which of these solutions are buffers? A) (1) and (2) C) (1), (2) and (3) B) (1) and (3) D) All are buffer solutions The following pictures represent solutions at various stages in the titration of a weak diprotic acid Hy A with aqueous KOH. shaded spheres represent atoms, black spheres represent oxygen atoms, and shaded spheres represent A2-ions. initially present, OH initially present and solvent water molecules have been omitted for clarity H -HA -HA -A ..OH (3) (4) (1) 13) Which picture represents the system halfway between the first and second equivalence points? A) (1) (3) D) (4) 14) Calculate the pH of a 0.100 M CHINH3Cl solution. Kh for methylamine, CHANH2, is 3.7.10-4 A) 8.22 B) 222 05.78 D) 11.78 15) Write a balanced equation for the dissociation of the Bronsted-Lowry add HSO4- in water. A) HSO4-) H2O) - S032-() + OH-) B) HSO4-ag) H2011) - H2SO4(47) + OH-(ar) C) HSO4-(aq) + H20(1) - SO42-(aq) + H3O+(ag) D) HSO4-(aq) + H2O(1) - S03(e) + OH-(aq) + H2O(1) 16) 16) A buffer solution is prepared by dissolving 27.22 g of KH2PO4 and 3.37 g of KOH in enough water to make 0.100 L of solution. What is the pH of the H2PO4-/HPO42- buffer if the Ka2-62. 10-8? A) 6.84 B) 7.84 7.21 D) 7.00

Answer 1

12. Buffer solution is made up of a acid of or base and their respective salts. According to this all of the picture shows the buffer solution

Correct option is D

13. Picture 3 represents the system halfway between the first and second equivalence point.

14) pot = -log [ort] poH = -log [ 0.100] =-X (-1) 1 pH poH = 14 pH = 14-1 pH = 13 15) Hsou + H₂O H₂ Ot (aq) + SO4² (aq) Hence, correct option is (c)