Answer
(a) $K^+$,$H_3O^+$,$I^-$,$CH_3COO^-$,$OH^-$,$CH_3COOH$ are the solute species present in the solution.
(b) $K^+$ is the most abundant species followed by $CH_3COO^-$.
(c) $OH^-$ is the least abundant species; the second least abundant species is $H_3O^+$.
Work Step by Step
(a) $K^+$,$H_3O^+$,$I^-$,$CH_3COO^-$,$OH^-$,$CH_3COOH$ are the solute species present in the solution.
(b) $K^+$(the predominant ion in highest concentration) is the most abundant species followed by $CH_3COO^-$ (produced in the neutralization of 3/4 of the $CH_3COOH$).
(c) $OH^-$ (the final solution is acidic, so $[OH^-]$ $\lt$$10^{-7}$) is the least abundant species; the second least abundant species is $H_3O^+$ (final solution as a buffer with $PH\approx5$).
