Question

2) Relate the ionic strengths 1 = }} <? (m:/mº) of solutions of the following electrolytes to the molal concentration m, of the solution: (a) KCI; (b) FeCl3; (c) CuSO4; (d) MgCl2; (e) Al2(SO4)3; (f) Fe2(SO4)3.

Answer 1

Jonie Streang-th, I = ? (mjm°). Con contrakion of ith Species in molali'ty Where ionic mi mel K Zi=Change of the ith Species 2 ionie Sireang th I, = So, the is dimentionless (1melkg So lutrons con sider for tae felooing Now, fotsing a) dss o cia te s as Solution Kel K Ca)+ a-Caq) Concentration ' Sue Se, Ionie treang th of Ke ff z ^ n ms Inel kg mst) ms Ikel ms dissociates as foll ewing Fe cl3 Fe(arj + 3 cu 3 Fe. Cl3 3.ms Con Centration : in molality 2

CC) dissocia tes Ce Con entrativn ' in melality Zcu2t 2 ms (molkg I(mol k -2 ms Cmelk 2- Se, Ionic Streamyth = 4ms 4 ms - 4 ms. M9c dissociates as inage ous Solutron 2+ Mg Cl2 agM). +2ei.- Can) Concevrtra tion in melality 2 ms 242 So, Foue o cantration, ms (malkg) Ienic Streamgth) I = = 3 ms

Al26042a Ce) dissociates im ageous So luton as A/2 Goys ( 2 Ai 3 Ca)+ 3 (So)(a9:) Concentration in melality 3ms 2 ms so = -2 2 3mnl K 2ms (molkg) Streangth T Tonic 2 ms+ 3 ms 18 ms + 12 ms 5 ms 17 dissociates -in aqueous Solutoh as- Csou3 Fe 2 2FeCan) +3 soy Fez Cs04) 3 ms 2 ms Con emtratio in molality - 3 3r(na1 Kg1) 2ms (me) ks 2. 3ms] 2 ms E2) = 8 ms 2 ms) 15 ms