The formula for the conjugate acid of s2- is
- The formula for the conjugate base of HPO ?- is
The Correct Answer and Explanation is:
Answers:
- The formula for the conjugate acid of S²⁻ is: HS⁻
- The formula for the conjugate base of HPO₄²⁻ is: PO₄³⁻
Explanation
In acid-base chemistry, the concept of conjugate acids and bases comes from the Brønsted-Lowry theory, which defines acids as proton (H⁺) donors and bases as proton acceptors. When a base gains a proton, it becomes its conjugate acid. Conversely, when an acid loses a proton, it becomes its conjugate base.
1. Conjugate Acid of S²⁻ (Sulfide Ion):
The sulfide ion (S²⁻) is a strong Brønsted-Lowry base because it can accept protons (H⁺). When it accepts one proton, it forms HS⁻ (hydrosulfide ion). Therefore: S2−+H+→HS−\text{S}^{2-} + \text{H}^+ \rightarrow \text{HS}^-
HS⁻ is the conjugate acid of S²⁻. If HS⁻ gains another proton, it would become H₂S (hydrogen sulfide), a weak diprotic acid.
2. Conjugate Base of HPO₄²⁻ (Hydrogen Phosphate Ion):
HPO₄²⁻ is a weak acid that can donate a proton. When it loses one proton, it forms PO₄³⁻ (phosphate ion). This is the conjugate base of HPO₄²⁻. The reaction is: HPO42−→PO43−+H+\text{HPO}_4^{2-} \rightarrow \text{PO}_4^{3-} + \text{H}^+
So, PO₄³⁻ is the species that remains after HPO₄²⁻ donates a hydrogen ion, making it the conjugate base.
Summary:
- Conjugate acid of S²⁻ = HS⁻
- Conjugate base of HPO₄²⁻ = PO₄³⁻
These relationships are crucial for understanding chemical equilibria, buffer systems, and acid-base reactions in both inorganic and biological systems.
