Which one is most stable to heat ?

Options

A. HClO
B. `HClO_2`
C. `HClO_3`
D. `HClO_4`

Answer

To determine which compound is most stable to heat among the given options, we can analyze the thermal stability of the oxoacids of halogens. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
First, we need to identify the compounds represented by the options A, B, C, and D. For this example, let's assume they are:
- A: HClO (Hypochlorous acid)
- B: HClO2 (Chlorous acid)
- C: HClO3 (Chloric acid)
- D: HClO4 (Perchloric acid)

### Step 2: Understand Oxoacid Stability
Oxoacids' stability generally increases with the oxidation state of the central atom (in this case, chlorine). As the oxidation state increases, the bond character of the central atom with oxygen becomes more covalent, leading to greater thermal stability.

### Step 3: Analyze Each Compound
- **HClO**: This is hypochlorous acid, which has chlorine in a lower oxidation state (+1). It is less stable to heat.
- **HClO2**: Chlorous acid has chlorine in a higher oxidation state (+3) than HClO, making it more stable than HClO but less stable than HClO4.
- **HClO3**: Chloric acid has chlorine in an even higher oxidation state (+5), which increases its stability further.
- **HClO4**: Perchloric acid has chlorine in the highest oxidation state (+7), making it the most stable to heat among these oxoacids.

### Step 4: Conclusion
Based on the analysis, we conclude that **HClO4 (Perchloric acid)** is the most stable to heat compared to the other options.

### Final Answer
The most stable compound to heat is **HClO4 (Option D)**.

---