Question

Which two elements are not balanced in this equation? `Na_2S + ZnCl_2 -> NaCl + ZnS`

Answer 1

The sodium and the chlorine atoms..........

Explanation:

`"Stoichiometry"` requires (i) that mass be balanced, and (ii) that charge be balanced........

We can put a check mark next to `(ii)`, but clearly for `(i)` there are 2 natrium reactants, and 1 natrium product, and 2 chlorine reactants, and 1 chlorine products:

And thus the stoichiometric equation is...........:

`Na_2S(aq) + ZnCl_2(aq) rarr ZnS(s)darr + 2NaCl(aq)`.

Are charge and mass balanced here? Don't trust my 'rithmetic!