Which oxy acids are stable only in aq. state not in solid state ?

Options

A. `HClO_(3), HClO_(4)`
B. `HBrO_(4), HIO_(4)`
C. `HBrO_(3), HIO_(3)`
D. `HBrO_(2), HIO_(2)`

Answer

To determine which oxy acids are stable only in aqueous state and not in solid state, we need to analyze the given options based on the oxidation states of the halogens and their stability in different states.

### Step-by-Step Solution:

1. **Identify the Oxy Acids**: The question provides four options of oxy acids:
- Option A: HClO3 and HClO4
- Option B: HBrO4 and HIO4
- Option C: HBrO3 and HIO3
- Option D: HBrO2 and HIO2

2. **Determine Oxidation States**:
- For Option A:
- HClO3: Chlorine (Cl) has an oxidation state of +5.
- HClO4: Chlorine (Cl) has an oxidation state of +7.
- For Option B:
- HBrO4: Bromine (Br) has an oxidation state of +7.
- HIO4: Iodine (I) has an oxidation state of +7.
- For Option C:
- HBrO3: Bromine (Br) has an oxidation state of +5.
- HIO3: Iodine (I) has an oxidation state of +5.
- For Option D:
- HBrO2: Bromine (Br) has an oxidation state of +3.
- HIO2: Iodine (I) has an oxidation state of +3.

3. **Classify the Oxy Acids**:
- Oxy acids can be classified based on the oxidation state of the central atom:
- Halous acids (oxidation state +3)
- Hypohalous acids (oxidation state +2)
- Halic acids (oxidation state +5)
- Perhalic acids (oxidation state +7)

4. **Stability in Solid State**:
- Halous acids (like HBrO2 and HIO2) are known to be unstable in solid state. They tend to decompose when in solid form, leading to the formation of halic and hypohalous acids.
- For example, HxO2 (where x is a halogen) decomposes in solid state to form HxO3 (halic) and HxO2 (hypohalous).

5. **Conclusion**:
- From the analysis, the oxy acids that are stable only in aqueous state and not in solid state are found in Option D: HBrO2 and HIO2.

### Final Answer:
The oxy acids that are stable only in aqueous state and not in solid state are **HBrO2 and HIO2** (Option D).