See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

(a) on mixing into (i) 3 2 4 2 4 4 PO H PO 2HPO 10 10 0 at eqbm 0 0 20       AITS-FT-IX (Paper-1)-PCM(Sol.)-JEE(Advanced)/2021 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com 10 (b) on mixing this into (ii) 2 3 4 4 HPO OH PO 20 10 0 at eqbm 10 0 10       (c) Now, on mixing this into (iii) 3 2 4 2 4 4 PO H PO 2HPO 10 10 0 at eqbm 0 0 10             2 4 2 4 HPO H H PO 20 15 0 at eqbm 5 0 15 So, final mixture is a buffer. Hence, 2 a 10 pH pK log 3