Question

Barium chloride solution can be used to distinguish between a sodium sulphate solution and sodium nitrate solution. How is this done?

Answer 1

Distinguishing Sodium sulphate and Sodium nitrate solution by using Barium chloride:

• This can be done by a Double-displace reaction, when aqueous Barium chloride $\left({\mathrm{BaCl}}_2\right)$ is mixed with Sodium sulphate $\left({\mathrm{NaSO}}_4\right)$ then in the presence of sulphate ions in solution, we obtained a white precipitate of Barium sulphate $\left({\mathrm{BaSO}}_4\right)$ and it is not soluble in water.
• The double displacement reaction is shown below:

$$\begin{gathered} {\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)\downarrow +2\mathrm{NaCl}\left(\mathrm{aq}\right) \\ \mathrm{Barium}\mathrm{Sodium}\mathrm{Barium}\mathrm{Sodium}\mathrm{Chloride} \\ \mathrm{chloride}\mathrm{sulphate}\mathrm{Sulphate} \end{gathered}$$

• Sodium nitrate$\left({\mathrm{NaNO}}_3\right)$ does not react with Barium chloride.

Therefore, it can be done with Double displacement reaction.