Write equations showing all of the equilibrium reactions occuring in aqueous solutions containing each of the following sets of reagents:
a. `NaCI`
b. `NaOH`
c. `NaC_(2)H_(3)O_(2) +HC_(2)H_(3)O_(2)`
d. `Na_(2)S + CuS`
e. `NH_(4)CI +NH_(3) + Mg(OH)_(2)(s)`

Explanation

All of them `(a)-(e)` involves: `2H_(2)O rarr H_(3)O^(oplus) +overset(Θ)OH`. In addition, (c) to (e) have following equilibrium:
c. `HC_(2)H_(3)O_(2) +H_(2)O hArr H_(3)O^(oplus) +C_(2)H_(3)O_(2)^(Θ)`
d. `CuS rarr Cu^(2+) + S^(2-)`
`S^(2-) +H_(2)O rarr HS^(Θ) +overset(Θ)OH`
`HS^(Θ) +H_(2)O rarr H_(2)S + overset(Θ)OH`
e. `NH_(3) +H_(2)O rarr overset(oplus)NH_(4) +overset(Θ)OH`
`Mg (OH)_(2) rarr Mg^(2+) +overset(Θ)OH`