Question

Calculate the pH of a solution formed by mixing 100.0 mL of 0.20 M HCIO with 200.0 mL of 0.30 M NACIO The Ka for HCIO is 2.9 x 10-8 ANSWER: ODA 10/ 7.54 7.06 5.99 6.46 8.01

Answer 1

Helo is a week acid and Naceo is a 1:1 salt electrolyte." H + 40 = Heo (weak acid) Naceo —— Nätt ceo ( Salt 100% dissociated Thies a buffer solution is make by mining of Hulo and Nacho ② And to know the pH of such solution, all use Henderson-Hasselbalch equation | | H = pke + log (conjugate base o calculate the holes 4 Heio from ginen data molarity and colume Molarity - I tumelt mono volumell)! #moles z Motauity x Wolune (ml) looo M=0. 20M 1 Va mul (100 ml) 7 #moles (0.20M) (100ml) 800 # moles A HUO = 0.020 Mole © moles of coom from date of Nlaceo - Molavily = 0.30 M volume a # moles - (0.30M)/200ml) goo ml. #moles - #moles 1000 0.060 moles] * Total volume s loome ( HCLO) + doomll Naceoj = 300 ml

volume (ml) - 300 ml 0.066 M volume (ml) 300 e Concentration 4 HClO (weak Acid) = # moles x 1000 [ Weak Alid): 0.020 y lovo Tweak Acid] 0.066M] o concentration of cloo , moles xlooo Conjugated,(6600) = 0.060xlovs [[60% 0.2M © boke is the negative logawithm of Ke. [pka = -logkal pkez - log (2.9810-8) boka = 7.537 Now use Hasselbatch eghi pleaca 7.537 [ weak Acid ), 0.066 M (conjugate Basej -0.2M ... ÞH 27.537 + dog 0.2 0.066 PH27.537 + 0.4814 bH> 8.0187
So the correct answer is last option 8.01