Question

In a chemical reaction between sulphuric acid and barium chloride solution the white precipitates formed are of:
1. Hydrochloric acid
2. Barium sulphate
3. Chlorine
4. Sulphur

Answer 1

Correct Answer - Option 2 : Barium sulphate

The correct answer is Barium sulfate.

• On reaction with the sulphuric acid solution, barium chloride forms a white precipitate of barium sulfate.
  • BaCl2​+H2​SO4​→BaSO4​+2HCl

• Double displacement reactions may be defined as the chemical reactions in which one component of each of both the reacting molecules is exchanged to form the products. 
  • ​​During this reaction, the cations and anions of two different compounds switch places, forming two entirely different compounds.
• Double displacement reactions generally take place in aqueous solutions in which the ions precipitate and there is an exchange of ions.
• For example, on mixing a solution of barium chloride with sodium sulfate, a white precipitate of barium sulfate is immediately formed. These reactions are ionic in nature.
  • The reactants change into ions when dissolved in water and there is an exchange of ions in solution. This results in the formation of a product molecule.
• Double displacement reactions can be further classified as neutralization, precipitation, and gas formation reactions.
• Neutralization reactions are a specific kind of double displacement reaction. An acid-base reaction occurs when an acid reacts with an equal quantity of base. The acid-base reaction results in the formation of salt (neutral in nature) and water.
•   \(HCI(aq)+NaOH(aq) \longrightarrow NaCI(aq)+H_2O(I)\)
• Precipitation is the formation of a solid in a solution or inside another solid during a chemical reaction.
  • ​This process usually takes place when the concentration of dissolved ions in the solution exceeds the solubility product.  
• A double displacement reaction should also occur if an insoluble gas is formed.  Gases such as HCl and NH3  are soluble in water, but some other gases, such as H2S,  are not soluble in water.