Write a molecular equation for the precipitation reaction that occurs (if any) when each pair of solutions is mixed. If no reaction occurs, write NO REACTION.
(a) potassium chloride and lead(II) acetate
(b) lithium sulfate and strontium chloride
(c) potassium bromide and calcium sulfide
(d) chromium(III) nitrate and potassium phosphate
Solution 68P :
To write the molecular equation for the precipitation reaction, we determine the formulas for the possible products using the general double displacement equation.
AB + CD → AD + CB
When 2 solutions of soluble and insoluble salts are mixed, the reaction is occurred and forms precipitation. Whereas, 2 solution of soluble salts are mixed, there will be no reaction as the salts in the solution dissolves and only ions are remained.
Based on this concept, we write the reactions and in the reactions, the reactants are solutions hence it will be indicated using (aq) and the insoluble product will be indicated using (s) which indicates it is solid state and soluble product is indicated using (aq) indicating the product is in liquid state.