ANS:B - dilute ammoniacal liquor

Dilute ammoniacal liquor is a solution containing ammonia (NH3) dissolved in water, typically prepared by diluting a concentrated ammonia solution with water. It is commonly used in various industrial processes for its properties as a basic solution and its ability to react with acidic compounds. Here's an explanation of the components and properties of dilute ammoniacal liquor:

1. Ammonia (NH3): Ammonia is a colorless gas with a characteristic pungent odor. It is highly soluble in water, forming a basic solution known as ammonium hydroxide (NH4OH) when dissolved. In dilute ammoniacal liquor, ammonia is present in its dissolved form as ammonium hydroxide.
2. Water (H2O): Water serves as the solvent in which ammonia dissolves to form the ammoniacal liquor. It is crucial for creating a solution with the desired concentration of ammonia.
3. Dilution: Dilute ammoniacal liquor is prepared by diluting a concentrated ammonia solution with water to achieve the desired concentration. The concentration of ammonia in the solution can vary depending on the specific application and requirements of the process.
4. Basic properties: Ammoniacal liquor is basic in nature due to the presence of ammonium hydroxide. It can neutralize acids and react with acidic compounds, forming water-soluble ammonium salts.
5. Applications: Dilute ammoniacal liquor finds various industrial applications, including:
   • Gas scrubbing: It is used to scrub and remove acidic gases, such as sulfur dioxide (SO2) or hydrogen chloride (HCl), from industrial gas streams.
   • pH adjustment: It is employed for pH control in wastewater treatment processes and in chemical synthesis reactions.
   • Chemical processing: It serves as a reactant or solvent in various chemical processes, particularly those requiring basic conditions.