What salt can furnish `H^(+)` in its aqueous solution?

Options

A. `NaH_(2)PO_(2)`
B. `Na_(2)HPO_(3)`
C. `Na_(2)HPO_(4)`
D. All of these

Answer

To determine which salt can furnish \( H^+ \) ions in its aqueous solution, we need to analyze the structure of the given salts and identify the presence of acidic protons. Here’s a step-by-step solution:

### Step 1: Understand the Concept of Furnishing \( H^+ \) Ions
- A salt can furnish \( H^+ \) ions if it contains hydrogen atoms that are bonded to electronegative atoms (like oxygen) which can release protons in solution.

**Hint:** Look for hydrogen atoms that are attached to electronegative atoms in the salt structure.

### Step 2: Analyze the Given Salts
1. **NaH₂PO₂**:
- Structure: \( P(=O)(-OH)(-H)(-O^-Na^+) \)
- The hydrogen atom is attached directly to phosphorus, not to an electronegative oxygen. Therefore, it cannot furnish \( H^+ \).

**Hint:** Check if the hydrogen is bonded to phosphorus or oxygen.

2. **Na₂HPO₃**:
- Structure: \( P(=O)(-OH)(-O^-Na^+)(-O^-Na^+) \)
- Similar to the first salt, the hydrogen atom is attached to phosphorus, so it cannot furnish \( H^+ \).

**Hint:** Look for the attachment of hydrogen to phosphorus again.

3. **Na₂HPO₄**:
- Structure: \( P(=O)(-O^-Na^+)(-O^-Na^+)(-OH) \)
- Here, the hydrogen atom is attached to an electronegative oxygen atom. This hydrogen can be released as \( H^+ \) in aqueous solution.

**Hint:** Identify the hydrogen attached to oxygen in this structure.

### Step 3: Conclusion
- Among the given salts, only **Na₂HPO₄** has a hydrogen atom that can furnish \( H^+ \) ions in its aqueous solution because it is bonded to an electronegative oxygen atom.

**Final Answer:** The correct salt that can furnish \( H^+ \) ions in its aqueous solution is **Na₂HPO₄**.