The equation which is balanced and represents the correct product(s) is

1. Li2O+2KCI→2LiCI+K2O

2.[CoCI(NH3)5]++5H+→Co2++5NH+4+CI−

3.[Mg(H2O)6]2++(EDTA)−4−→−−−−−−−ExcessNaOH [Mg(EDTA)]2++6H2O

4.CuSO4+4KCN→K2[Cu(CN)4]+K2SO4

Answer:

on adding acid, ammine complexes get destroyed.

(a) Li2O+KCI→2LiCI+K2O

This is wrong equation, since a stronger base K2O cannot be generated by a weaker base Li2O.

(b) [CoCI(NH3)5]+5H→Co2+(aq)+5NH+4+CI−

This is correct. All ammine complexes can be destroyed by adding 11th Hence on adding acid to [CoCI(NH3)5] it gets converted to Co2−(aq)+ NH−3 and CI−

(c) [Mg(H2O)6]2−+EDTA4−−→−−−ExcessOH[Mg(EDTA)]2+ +6H2O

This is wrong, since the formula of complex must be [Mg(EDTA)]2+ as EDT

(d) 4th reaction is incorrect

correct representation as

2CuSO4+10KCN→2K3[Cu(CN)4] +2K2SO4+(CN)2↑