Question

Which method is employed for the preparation of sulphate of \(\mathrm{Ba}\), \(\mathrm{Ca}\) and \(\mathrm{Pb}\) ?

Short answer

Answer: The method employed for the preparation of sulphate of barium, calcium, and lead is precipitation.

Step-by-step solution

Identify the cations and anions in the given compounds

The given compounds are sulphates of barium (Ba), calcium (Ca), and lead (Pb). These are ionic compounds formed between metal cations (Ba\(^{2+}\), Ca\(^{2+}\), and Pb\(^{2+}\)) and the sulphate anion (SO\(_4^{2-}\)).

Review the common methods of preparation of metal sulphates

The common methods of preparation of metal sulphates are: 1. Precipitation: Mixing solutions of two soluble salts, one containing the desired cation and the other containing the sulphate anion. 2. Acid-base reactions: Reacting a metal oxide or hydroxide with a sulphuric acid. 3. Redox reactions: These reactions involve transfer of electrons and are less common in the preparation of sulphates.

Choose the appropriate method for the preparation of BaSO4, CaSO4, and PbSO4

All three sulphates can be prepared by precipitation, as they are all insoluble compounds. Let's write the precipitation reactions for each metal sulphate: 1. Barium sulphate (BaSO4): BaCl2 (aq) + Na2SO4 (aq) --> BaSO4 (s) + 2 NaCl (aq) 2. Calcium sulphate (CaSO4): CaCl2 (aq) + Na2SO4 (aq) --> CaSO4 (s) + 2 NaCl (aq) 3. Lead sulphate (PbSO4): Pb(NO3)2 (aq) + Na2SO4 (aq) --> PbSO4 (s) + 2 NaNO3 (aq)

Conclusion

The method employed for the preparation of sulphate of Ba, Ca, and Pb is precipitation. They can be prepared by mixing a solution containing the metal cation and another containing the sulphate anion, leading to the formation of the insoluble metal sulphate which precipitates out of the solution.