Question

How do I write the neutralization reactions between: (a) calcium carbonate and hydrogen bromide; (b) cadmium oxide and hydrogen chloride; (c) ferric oxide and nitric acid; (d) sodium oxide and water?

Answer 1

`a.` `CaCO_3(s) + 2HBr(aq) rarr CaBr_2(aq) + H_2O(l) + CO_2(g)uarr` `("calcium bromide")`

Explanation:

`b.` `CdO(s) + 2HCl(aq) rarr CdCl_2(aq) + H_2O(l)` `("cadmium chloride")`

`c.` `Fe_2O_3(s) + 6HNO_3(aq) rarr 2Fe(NO_3)_3(aq) + 3H_2O(l)`
`("ferric nitrate or iron(III) nitrate")`

`d.` `Na_2O(s) + H_2O(l) rarr 2NaOH(aq)`
`("sodium hydroxide")`

`H_2SO_4(aq) + 2NaOH(aq) rarr Na_2SO_4(aq) + 2H_2O(aq)`
`("sodium sulfate")`

All of these equations (I think) are balanced with respect to mass and charge, as they must be if they reflect chemical reality. How do you know which products form? How else but by experiment?

And all of these reactions are variations on a theme of acid base reactions:

`"Acid + base "rarr" salt and water"`

Most of the time, the metal salt remains in solution and is along for the ride. The net ionic equation is simply:

`H_3O^(+) + HO^(-) rarr 2H_2O(l)`