Question

When 2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc in a test tube and then warmed, the reaction that occurs can be written in the form of a balanced chemical equation as:

• A. NaOH + Zn → NaZnO₂ + H₂O
• B. 2NaOH + Zn → Na₂ZnO₂ + H₂
• C. 2NaOH + Zn → NaZnO₂ + H₂
• D. 2NaOH + Zn → Na₂ZnO₂ + H₂O

Answer 1

The Correct Option is B

Step 1: Understanding the reaction:
When sodium hydroxide (NaOH) is added to zinc (Zn) and the mixture is heated, a reaction occurs where sodium zincate (Na₂ZnO₂) and hydrogen gas (H₂) are produced.

Step 2: The chemical reaction:
The reaction between sodium hydroxide and zinc can be described as follows: - Sodium hydroxide (NaOH) reacts with zinc (Zn) to form sodium zincate (Na₂ZnO₂) and hydrogen gas (H₂). The balanced chemical equation for this reaction is: \[ 2\text{NaOH} + \text{Zn} \rightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2 \]

Step 3: Conclusion:
The reaction between sodium hydroxide and zinc when heated produces sodium zincate and hydrogen gas. Therefore, the correct balanced chemical equation is: \[ 2\text{NaOH} + \text{Zn} \rightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2 \]