# The following chemical reaction takes place in aqueous solution: ZnCl_2(aq) + Na_2S(aq) => ZnS(s)...

## Question:

The following chemical reaction takes place in aqueous solution:

ZnCl{eq}_2 {/eq}(aq) + Na{eq}_2 {/eq}S(aq) {eq}\to {/eq} ZnS(s) + 2NaCl(aq)

write the net ionic equation for this reaction.

## Ionic Equations:

An aqueous solution is a homogeneous mixture where liquid water acts as the solvent for one or more dissolved species (solutes). In many cases these solutes have a net positive or negative charge. Examples include species involved in acid-base, redox or precipitation reactions. The ionic equation is distinct from a conventional molecular form by writing highly dissociated species in terms of their ionic components, with such species possibly present on both sides of the equation. If there are ionic species that do not take part in the reaction of interest, then they are spectators and omitted in the net form of the ionic equation.

The given molecular reaction equation is:

{eq}\rm ZnCl_2 (aq) + Na_2S (aq) \rightarrow ZnS (s) + 2NaCl (aq) {/eq}

This is a precipitation reaction where ZnS is the solid product. It is formed by constituent ions provided by the two different salt compound reactant solutions. The sodium cations and chloride anions remain in solution. They are spectators in the precipitation process, so they are omitted in the net ionic equation:

{eq}\boxed{\rm Zn^{2+} (aq) + S^{2-} (aq) \rightarrow ZnS (s) }{/eq}