Answer:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The total ionic equations shows the equation in which all the species of the reactants and the products are in dissociated form and are represented as ions.
The net ionic equations shows the equation in which all the species of the reactants and the products are in dissociated form and do not show the spectator ions which are same in the reactants and the products.
a) zinc nitrate + calcium sulphide [tex]\rightarrow [/tex] zinc sulphide + calcium nitrate
balance equation : [tex]Zn(NO_3)_2(aq)+CaS(aq)\rightarrow ZnS(s)+Ca(NO_3)_2(aq)[/tex]
total ionic equation :
[tex]Zn^{2+}(aq)+2NO_3^-(aq)+Ca^{2+}(aq)+S^{2-}(aq)\rightarrow ZnS(s)+Ca^{2+}(aq)+2NO_3^-(aq)[/tex]
net ionic equation :
[tex]Zn^{2+}(aq)++S^{2-}(aq)\rightarrow ZnS(s)[/tex]
b) potassium + calcium chloride [tex]\rightarrow [/tex] potassium chloride + calcium
balance equation : [tex]2K(s)+CaCl_2(aq)\rightarrow 2KCl(aq)+Ca(s)[/tex]
total ionic equation :
[tex]2K(s)+Ca^{2+}(aq)+2Cl^-(aq)\rightarrow 2K^+(aq)+2Cl^-(aq)+Ca[/tex]
net ionic equation: [tex]2K(s)+Ca^{2+}(aq)+\rightarrow 2K^+(aq)++Ca[/tex]
