- Select soluble reagents: \(BaCl_2(aq)\) and \(Na_2SO_4(aq)\).
- Isolate the precipitate through filtration, washing, and drying the collected residue.
- The balanced equation is \(BaCl_2(aq) + Na_2SO_4(aq) \rightarrow BaSO_4(s) + 2NaCl(aq)\).
- The net ionic equation is \(Ba^{2+}(aq) + SO_4^{2-}(aq) \rightarrow BaSO_4(s)\), identifying the precipitate as \(\boxed{BaSO_4(s)}\).
Explanation
- Selection of Reactants
To synthesize barium sulphate (\(BaSO_4\)), we must perform a precipitation reaction. We need two soluble ionic compounds that provide the necessary barium ions (\(Ba^{2+}\)) and sulphate ions (\(SO_4^{2-}\)). Mixing solutions of barium chloride (\(BaCl_2\)) and sodium sulphate (\(Na_2SO_4\)) is an ideal approach, as barium chloride and sodium sulphate are both highly soluble in water. Their reaction leads to the formation of insoluble barium sulphate as a solid precipitate, while sodium chloride remains dissolved in the solution.
- Isolation of Barium Sulphate
Once the precipitation reaction has occurred, the mixture contains solid barium sulphate suspended in a solution of sodium chloride and water. To isolate the solid, we perform a filtration process. The mixture is poured through filter paper in a funnel. The solid barium sulphate, being insoluble, is trapped by the filter paper as residue, while the filtrate (the liquid passing through) contains the dissolved sodium chloride. After filtration, the residue should be washed with distilled water to remove any residual sodium chloride and subsequently dried to obtain pure barium sulphate.
- Balanced Chemical Equation
The chemical equation describes the interaction between the reactants and the formation of products with their respective states of matter. The balanced chemical equation is:
\[BaCl_2(aq) + Na_2SO_4(aq) \rightarrow BaSO_4(s) + 2NaCl(aq)\]
In this equation, \((aq)\) indicates that the substances are in an aqueous solution, and \((s)\) indicates the formation of a solid precipitate.
- Net Ionic Equation
To represent the reaction at the ionic level, we isolate the ions that actively participate in forming the precipitate. Since barium chloride, sodium sulphate, and sodium chloride are strong electrolytes, they dissociate completely in water. The net ionic equation, which removes spectator ions (sodium and chloride ions that do not participate in the reaction), is:
\[Ba^{2+}(aq) + SO_4^{2-}(aq) \rightarrow BaSO_4(s)\]
This equation highlights the core chemical process: the combination of barium and sulphate ions to form the solid product.
- Identification of the Precipitate
The precipitate is the solid substance that forms and separates from the solution. In the provided net ionic equation, the substance denoted with the state symbol \((s)\) is barium sulphate. Therefore, the precipitate is \(\boxed{BaSO_4(s)}\).
Examples
In environmental science, identifying and removing heavy metal contaminants from water is a critical process. For instance, precipitation reactions similar to the one used for barium sulphate are employed in water treatment plants to remove pollutants like lead or cadmium. By adding specific chemical agents to industrial wastewater, contaminants can be turned into solid precipitates that are easily filtered out, ensuring the purified water meets safety standards before it is discharged back into the environment.