Question

How to balance complicated chemical equations?

Answer 1

Every chemical equation balances MASS and CHARGE.......

Explanation:

You gots a metal carbonate, say `ZnCO_3(s)`:

`ZnCO_3(s) + 2HCl(aq) rarr ZnCl_2(aq) + CO_2(g)uarr+H_2O(l)`

Are mass and charge balanced here? If they are not then you cannot accept the equation as a representation of chemical reality. And if you start with `10*g` of reactant from all sources, you inevitably finish with `10*g` product.......

The lesson that I try to reinforce is that `"mass and charge are CONSERVED"`.

Carbonates (and these are often insoluble salts) react with acids according to the following net ionic equation......

`CO_3^(2-) + 2H^(+) rarr CO_2(g) +H_2O(l)`

You simply have to know these reactions, and how to balance them stoichiometrically.

And likewise for bicarbonates......

`HCO_3^(-) + H^(+) rarr CO_2(g)uarr + H_2O(l)`

Bicarbonate salts TEND to be soluble. Carbonate salts tend to be insoluble. But this is the province of experiment.