Question

Consider the following data on some weak acids and weak bases: acid name formula hypochlorous acid HCIO 3.0*10* hydrocyanic acid HCN 4.9*10-10 base name formula pyridine C H N 1.7*10-9 methylamine CH, NH, 4.4 x 104 Use this data to rank the following solutions in order of increasing pH. In other words, select a 'l' next to the solution that will have the lowest pH, a 2 next to the solution that will have the next lowest pH, and so on. solution 0.1 M NACN 0.1 M Nac 1838 IST 13 0.1 MCHNHCI 0.1 MKCIO

Answer 1

Drower: · Acid Hypochlorous acid noo pka = -log (ka) E-log (3x108) = 7.52 pH = plea + log [wojegate bas] dio [and] suppose, Zential cone of 140 1.0n исtо o = по“, со o O.IM o.lt 1.0-X at gruelibonim ka = (x) (ə.14) small so olta ~ 0.1 to is very 3x10 = (x) (0.1) x= 3x107 m [not] =*= 3x10 m г. - 1а Гио" ) lph = 6.52

Hydesugare and heN suppose HON 1.0M Tontially HEN tho ² not tcne Initial 01 + At aquelitoum I-T to @)(ole) (1-x) ka is very small so oolta ~ 0.1 4o 9x 10-40 d (0.1) =4.9x10-9 ph= -log (&) = 8.309 peysidine i hn suppose ch N=1.0M Initially GN + no = shann ton I 0.14 a Rritead Alsquchiboun 1-X Kto = a) (olte) ko is very small to, 0.1+4~0.1

1.7x10 = () (2.1) 2.1.7 x108 M pon = -log(x) = 7.769 ph + рол - у (pn = 6:23] methylamine suppose cyan = 1.0r1 Laitially chan tho cunnon Jaution After Equilibrum 1-4 ko is very small so 1-aal x=0.0209 M pon = -log (0.0209) 1.678 ph+ pon = 14 ph= 12.32

compound - Hclo 6.52 HCN 8.309 6.23 ch Nha 12.32 chNn 3 2 > Men > nulo> shan Increasing order of ph value.