Which of the following does not contain coordinate bond?

Options

A. `PH_(4)^(+)`
B. `NO_(2)`
C. `O_(3)`
D. `CO_(3)^(2-)`

Answer

To determine which of the given options does not contain a coordinate bond, we need to analyze each molecule and identify whether a coordinate bond is present. A coordinate bond (or dative bond) is formed when one atom provides both electrons for a bond.

### Step-by-Step Solution:

1. **Analyze Option A: PH4+**
- Phosphorus (P) has a valency of 5, and with 4 hydrogen atoms (each contributing 1 electron), it forms 4 bonds.
- The phosphorus atom shares its electrons with hydrogen atoms, and since it provides both electrons for one of the bonds (with one hydrogen), this molecule contains a coordinate bond.
- **Conclusion**: PH4+ contains a coordinate bond.

2. **Analyze Option B: NO2**
- Nitrogen (N) has a valency of 5, and each oxygen (O) has a valency of 6. In NO2, nitrogen shares its electrons with two oxygen atoms.
- To satisfy the octet rule, nitrogen forms a double bond with one oxygen, where nitrogen provides both electrons for this bond. This indicates the presence of a coordinate bond.
- **Conclusion**: NO2 contains a coordinate bond.

3. **Analyze Option C: O3 (Ozone)**
- Each oxygen atom has a valency of 6. In ozone, the structure consists of a double bond between two oxygen atoms and a single bond with the third oxygen.
- The central oxygen atom shares its electrons with the other two, and one of the bonds is formed by the central oxygen providing both electrons. Thus, this molecule also contains a coordinate bond.
- **Conclusion**: O3 contains a coordinate bond.

4. **Analyze Option D: CO3 2- (Carbonate Ion)**
- Carbon (C) has a valency of 4, and each oxygen has a valency of 6. In the carbonate ion, carbon is bonded to three oxygen atoms, with one double bond and two single bonds.
- In this case, no atom provides both electrons for bonding; rather, the electrons are shared equally among the atoms. Therefore, there are no coordinate bonds present in CO3 2-.
- **Conclusion**: CO3 2- does not contain a coordinate bond.

### Final Answer:
The molecule that does not contain a coordinate bond is **Option D: CO3 2-**.