Assuming complete ionization in dilute aqueous solution, which of the following complex coordination — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

$Al_2(SO_4)_3$ completely dissociates into $2 Al^{3+}$ and $3 SO_4^{2-}$ ions, giving $n=5$. For $100\%$ ionization, $i=5$. Solutions with the same effective concentration ($i \times m$) have the same freezing point. $K_4[Fe(CN)_6]$ yields $4 K^+$ and $1 [Fe(CN)_6]^{4-}$ ($i=5$). $[Pt(NH_3)_6]Cl_4$ yields $1 [Pt(NH_3)_6]^{4+}$ and $4 Cl^-$ ($i=5$). Thus, A and B are correct. Options C and D only yield $n=4$ ions ($i=4$).