Which of the following contains a coordinate covalent bond?

Options

A. `N_(2)H_(5)^(+)`
B. `BaCl_(2)`
C. `HCl`
D. `H_(2)O`

Explanation

To determine which of the given compounds contains a coordinate covalent bond, we can analyze each option step by step.

### Step 1: Understand Coordinate Covalent Bonds
A coordinate covalent bond (also known as a dative bond) is formed when one atom donates both of the electrons to be shared with another atom. This is different from a regular covalent bond where each atom contributes one electron.

### Step 2: Analyze Each Compound
1. **BACL2 (Barium Chloride)**:
- In BACL2, barium (Ba) donates its electrons to chlorine (Cl) to form ionic bonds. There are no coordinate covalent bonds here.

2. **SCL (Sodium Chloride)**:
- SCL is also an ionic compound where sodium (Na) donates an electron to chlorine (Cl). Again, there are no coordinate covalent bonds.

3. **S2O (Disulfur Monoxide)**:
- In S2O, sulfur and oxygen form covalent bonds. However, there is no indication of a coordinate covalent bond in this molecule.

4. **N2H5+ (Hydrazinium Ion)**:
- The structure of N2H5+ shows that nitrogen atoms share electrons with hydrogen atoms. In this case, one nitrogen atom donates both electrons to form a bond with the other nitrogen atom, creating a coordinate covalent bond.

### Step 3: Conclusion
After analyzing all the options, we find that the only compound that contains a coordinate covalent bond is **N2H5+**. Therefore, the correct answer is option **A: N2H5+**.

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