JEE Main · 2014 · 06 Apr 2014 · Offline · Coordination Compounds

Check each line for balance and for sensible products. The magnesium-EDTA line does not balance in charge, $-2$ on the left against $+2$ on the right. Copper with excess cyanide actually gives $\mathrm{K}{}_3[\mathrm{Cu}(\mathrm{CN}){}_4]$, not $\mathrm{K}{}_2[\mathrm{Cu}(\mathrm{CN}){}_4]$. The $\mathrm{Li}{}_2\mathrm{O}+\mathrm{KCl}$ line runs the wrong way, since $\mathrm{Li}{}_2\mathrm{O}$ is stable while $\mathrm{K}{}_2\mathrm{O}$ is not. The reaction $[\mathrm{CoCl}(\mathrm{NH}{}_3){}_5]{}^{+}+5\mathrm{H}{}^{+}\to \mathrm{Co}{}^{2+}+5\mathrm{NH}{}_4{}^{+}+\mathrm{Cl}{}^{-}$ is both correct and balanced in atoms and charge, so it represents the right products.