Consider the following statements and arrange in the order of true/false as given in the codes.
`S_1`:Ammonia on heating with concentrated solution of sodium hypochlorite gives nitrogen gas.
`S_2`:The phosphine gas dissolves in water in presence of sunlight and produces phosphonium hydroxide like ammonium hydroxide.
`S_3`:Barium azide on heating gives pure nitrogen gas.
`S_4`:The oxo-acids of phosphorus in which phosphorus has lower oxidation state less than +5 contain either P-P or P-H bonds but not both in addition to P=O and P-OH bonds.

Options

A. TFTT
B. FFTT
C. TTTF
D. TFTF

Explanation

To determine the truth value of the statements provided in the question, we will analyze each statement one by one.

### Step-by-step Solution:

1. **Statement S1**: "Ammonia on heating with concentrated solution of sodium hypochlorite gives nitrogen gas."
- When ammonia (NH₃) is heated with sodium hypochlorite (NaOCl), a reaction occurs where ammonia is oxidized to nitrogen gas (N₂), along with the formation of sodium chloride (NaCl) and water (H₂O).
- **Conclusion**: This statement is **True**.

2. **Statement S2**: "The phosphine gas dissolves in water in presence of sunlight and produces phosphonium hydroxide like ammonium hydroxide."
- Phosphine (PH₃) is known to have low solubility in water. Unlike ammonia (NH₃), which can form hydrogen bonds with water, phosphine does not engage in such bonding. Therefore, it does not dissolve in water to produce phosphonium hydroxide.
- **Conclusion**: This statement is **False**.

3. **Statement S3**: "Barium azide on heating gives pure nitrogen gas."
- When barium azide (Ba(N₃)₂) is heated, it decomposes to produce nitrogen gas (N₂) and barium (Ba). The reaction can be represented as:
\[ Ba(N₃)₂ \rightarrow Ba + 3N₂ \]
- **Conclusion**: This statement is **True**.

4. **Statement S4**: "The oxo-acids of phosphorus in which phosphorus has lower oxidation state less than +5 contain either P-P or P-H bonds but not both in addition to P=O and P-OH bonds."
- Oxo-acids of phosphorus, such as H₃PO₃ (phosphorous acid), have phosphorus in a +3 oxidation state and can contain P-H bonds. Other oxo-acids, such as H₄P₂O₅, can contain P-P bonds. However, they do not contain both types of bonds simultaneously in the same structure.
- **Conclusion**: This statement is **True**.

### Final Arrangement of Statements:
- S1: True
- S2: False
- S3: True
- S4: True

Thus, the final order of the statements is: **True, False, True, True**.