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

Options

A. `Li_(2)O+2 KCl rarr 2 LiCl+K_(2)O`
B. `[CoCl(NH_(3))_(5)]^(+)+5H^(+) rarr Co^(2+)+5 NH_(4)^(+) +Cl^(-)`
C. `[Mg(H_(2)O)_(6)]^(2+)+("EDTA")^(4-) overset("excess NaOH")(rarr) [Mg(EDTA)]^(2+)`
D. `CuSO_(4)+4KCN rarr K_(2)[Cu(CN)_(4)]+K_(2)SO_(4)`

Answer

B

Explanation

(a) `Li_(2)O + KCl rarr 2LiCl + K_(2)O`
wrong equation, since a stronger base `(K_(2)O)` cannot be generated by a weaker base `Li_(2)O`.
(b) `[CoCl(NH_(3))_(5)] + 5H^(oplus) rarr CO^(2+) (aq) + 5NH_(4)^(oplus) + Cl^(-)`
This is correct. All ammine complexes can be destroyed by adding `H^(oplus)`.
(c) `[Mg(H_(2)O)_(6)]^(2+) EDTA^(4-) underset("excess")overset(OH^(-))rarr [Mg(EDTA)]^(2+) + 6H_(2)O` This is wrong, since the formula of complex must be `[Mg("edta")]^(2-)`
(d) `2CuSO_(4) + 10KCN rarr 2K_(3)[Cu(CN)_(4)] + 2K_(2)SO_(4) + (CN)_(2) uarr` It is a wrong option