In an experiment investigating chemical properties, what is the purpose of adding sodium carbonate (Na2CO3) in part 1a?

• A. To precipitate metal ions as insoluble carbonates
• B. To act as a base and neutralize acidic components
• C. To serve as an oxidizing agent
• D. To provide a source of chloride ions

Answer: (B)

Verified step by step guidance

1. Identify the chemical nature of sodium carbonate (Na2CO3). It is a salt that dissociates in water to give carbonate ions (CO3^{2-}) and sodium ions (Na^+).
2. Understand the role of carbonate ions in solution. Carbonate ions can act as a base by accepting protons (H^+) and can also react with metal ions to form insoluble carbonates.
3. Analyze the options given: (a) precipitating metal ions as insoluble carbonates, (b) acting as a base to neutralize acidic components, (c) serving as an oxidizing agent, and (d) providing chloride ions.
4. Recall that sodium carbonate is not an oxidizing agent and does not provide chloride ions, so options (c) and (d) can be eliminated.
5. Focus on the difference between precipitating metal ions and neutralizing acid. If the experiment's goal is to neutralize acidic components, sodium carbonate acts as a base by reacting with acids to form water and carbon dioxide, thus neutralizing the acid.