Question

a. What is the K_b for HC₂O₄^-?

b. The pH of a 2.5 M solution of a weak base is 12.68. What is the Kb for this base?

c. The pH of a 1.50 M solution of a weak acid is 2.405. What is the Ka for this acid?

d. Calcuate the pH of a 1.52 M solution of NH₃.

Answer 1

Фk, Fч, чо и со хеч К», но, - , rt bа t 4,4%, 1.ox 14 S3 x|-- 12 90 k, T. Rь хто I weak base, į [ 6 ] = 2,5M com , 14+ — 12, 68 с pH = 12 68 с | 32 [65] . rен бо +3+6 I R. 3- + + 6 — p 2. У х + + — — — о. 64 6 4 0,442 . — — 3-o. o4586 Свн] tон) (С, съесі kb = — 2 (2.5- . o 446 ) [B-T , 3 4 XL k, 2 Scanned with CamScanner

& HA Ginen PH=2.405 CHAJ = 1.50 & [H+] - 10 14+] = 10PH = 102405 -0.00394 Now, H - H t sot I 150 - tre J E (1.50 - 0,00394) 0.00394 0.00394 (0.06394 á (1.58 -0,00394) ko Ent][A] /CHA) 9 kg = ka- 1.035 x 105 Bus

@ alren! [ Nits] = 1.52M 4 = 1.8x105 t Nth tho + oH 1.52 A can но ) E1.52 x 224 po Kp = Carly t] Lon] [NHG] x.re re 1.8 x 10 1.52 -a 1.52-x 1.52-x n 152 s 1-88 10 cal 2.736 x 10 = 1.52 x 18x1-5 x= 0.00523 = 0,00523 M Tor1 = x 0,00123 pOH = -log com = -log 0,00523 pH = 14- pon pou = 2.28 H = 11.72 CS Scannedpis 14 - 2:28 CamScanner

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