Zn(OH)2 is a:

A. Acidic base

B. Diacidic base

C. Triacidic base

D. Tetracidic base

To determine the classification of Zn(OH)2, we need to analyze its chemical structure and properties. Zinc hydroxide, Zn(OH)2, is a compound formed from zinc and hydroxide ions. In this case, it behaves as a base, specifically a diacidic base. Let's break this down further to understand why.

Understanding Zinc Hydroxide

Zinc hydroxide consists of one zinc ion (Zn²⁺) and two hydroxide ions (OH⁻). The presence of two hydroxide ions indicates that it can react with acids to neutralize them, which is a characteristic behavior of bases.

Classification of Bases

Bases can be classified based on the number of hydroxide ions they contain. Here’s how the options break down:

• Acidic base: This term is somewhat misleading, as it typically refers to substances that can act as both acids and bases, but it doesn't apply directly to Zn(OH)2.
• Diacidic base: This means the compound can donate two hydroxide ions, which is exactly what Zn(OH)2 does.
• Triacidic base: This would imply the ability to donate three hydroxide ions, which Zn(OH)2 cannot do.
• Tetracidic base: Similar to triacidic, this would suggest four hydroxide ions, which is also not applicable here.

Why Diacidic Base?

In the context of Zn(OH)2, the term "diacidic base" is appropriate because it can react with two protons (H⁺ ions) from acids. For example, when zinc hydroxide reacts with hydrochloric acid (HCl), the reaction can be represented as:

Zn(OH)2 + 2 HCl → ZnCl2 + 2 H2O

In this reaction, two hydroxide ions are neutralized by two protons from the hydrochloric acid, confirming that Zn(OH)2 can indeed act as a diacidic base.

Conclusion

In summary, Zn(OH)2 is best classified as a diacidic base because it contains two hydroxide ions that can react with acids. This classification helps us understand its behavior in various chemical reactions and its role in neutralization processes. Therefore, the correct answer to your question is B. Diacidic base.