Question

What will be formed from the reaction: NaOH + Zn $\rightarrow$ ?

• A. Sodium Zincate and Hydrogen gas
• B. Zinc Oxide and Sodium
• C. Sodium Hydride and Zinc
• D. No reaction will occur

Hint:

Amphoteric metals like zinc (Zn) and aluminum (Al) can react with strong bases (like NaOH) to produce a complex salt and hydrogen gas. This is an important property distinguishing them from metals that only react with acids.

Answer 1

The Correct Option is A

Step 1: Reaction of a Base with an Amphoteric Metal
Sodium hydroxide (NaOH), a strong base, reacts with zinc (Zn), an amphoteric metal. This reaction yields a salt and hydrogen gas. Amphoteric metals react with both acids and bases; zinc is a prime example.
Step 2: Balanced Chemical Equation
Zinc reacting with sodium hydroxide solution produces sodium zincate (Na₂ZnO₂) and hydrogen gas (H₂). The balanced chemical equation:

 2NaOH(aq) + Zn(s) → Na2ZnO2(aq) + H2(g)
 

Step 3: Option Evaluation

• Option (a): Sodium Zincate and Hydrogen gas: This accurately reflects the reaction's products, as shown in the equation.
• Option (b): Zinc Oxide and Sodium: This is incorrect. Zinc oxide is not formed, nor is sodium metal a product.
• Option (c): Sodium Hydride and Zinc: This is incorrect. Neither sodium hydride is formed, nor is zinc a product; it's a reactant.
• Option (d): No reaction will occur: Incorrect. Zinc, being amphoteric, readily reacts with strong bases like NaOH.

Step 4: Conclusion
NaOH and Zn react to produce sodium zincate and hydrogen gas.
Conclusion:

Sodium Zincate and Hydrogen gas