Products from Copper Sulphate and Sodium Carbonate Reaction

When a solution of copper sulphate ($\text{CuSO}_4$) is mixed with a solution of sodium carbonate ($\text{Na}_2\text{CO}_3$), a chemical reaction occurs. This reaction is a type of double displacement reaction, but it involves more than just swapping ions because the carbonate ion undergoes hydrolysis in water.

The overall reaction results in the formation of a precipitate, a dissolved salt, and a gas.

The primary products are:

• Basic copper carbonate: This is the solid precipitate formed. It's not just simple copper carbonate ($\text{CuCO}_3$). Copper carbonate in aqueous solution is unstable and reacts with water to form a basic copper carbonate, which is a mixture of copper(II) carbonate and copper(II) hydroxide, often represented by formulas like $\text{Cu}_2(\text{OH})_2\text{CO}_3$. This is the green or blue precipitate you would observe.
• Sodium sulphate: This salt ($\text{Na}_2\text{SO}_4$) remains dissolved in the solution. Sodium and sulphate ions are spectator ions in terms of precipitation, but they form sodium sulphate as one of the soluble products.
• Carbon dioxide: A gas ($\text{CO}_2$) is evolved during the reaction, particularly as the carbonate ion reacts with water in the presence of metal ions.

The balanced chemical equation representing this reaction is commonly written as:

$\text{2CuSO}_4\text{(aq)} + \text{2Na}_2\text{CO}_3\text{(aq)} + \text{H}_2\text{O(l)} \rightarrow \text{Cu}_2(\text{OH})_2\text{CO}_3\text{(s)} + \text{2Na}_2\text{SO}_4\text{(aq)} + \text{CO}_2\text{(g)}$

Looking at the options provided:

• Option 1 lists Basic copper carbonate, sodium sulphate and CO₂. This matches the products derived from the reaction and the common representation of the outcome.
• Option 2 lists Copper hydroxide, sodium sulphate and CO₂. While copper hydroxide is a component of basic copper carbonate, it is not the sole copper-containing precipitate formed; the precipitate is a mixture or a specific compound containing both carbonate and hydroxide.
• Option 3 lists Copper carbonate, sodium sulphate and CO₂. Simple copper carbonate ($\text{CuCO}_3$) is generally unstable in aqueous solution and readily converts to basic copper carbonate, so $\text{CuCO}_3$ alone is not the final stable copper product obtained.

Based on the chemical reaction between copper sulphate and sodium carbonate in aqueous solution, the main products obtained are basic copper carbonate (as a precipitate), sodium sulphate (dissolved), and carbon dioxide gas.