The correct order of acid strength is

Options

A. `HClO_(4) lt HClO_(3) lt HClO_(2) lt HClO`
B. `HClO_(2) lt HClO_(3) lt HClO_(4) lt HClO`
C. `HClO_(4) lt HClO lt HClO_(2) lt HClO_(3) `
D. `HClO lt HClO_(2) lt HClO_(3) lt HClO_(4)`

Answer

To determine the correct order of acid strength for the given oxyacids of chlorine (HClO4, HClO3, HClO2, and HClO), we will analyze the oxidation states of chlorine in each acid and relate them to their acidic strength.

### Step-by-Step Solution:

1. **Identify the Acids**: We have four acids to consider: HClO4, HClO3, HClO2, and HClO.

2. **Calculate the Oxidation State of Chlorine in Each Acid**:
- For **HClO4**:
- Let the oxidation state of Cl be \( X \).
- The equation based on oxidation states is:
\[ X + 1 - 8 = 0 \quad \text{(since there are 4 oxygen atoms, each with -2)} \]
- Solving gives:
\[ X = +7 \]

- For **HClO3**:
- The equation is:
\[ X + 1 - 6 = 0 \quad \text{(3 oxygen atoms)} \]
- Solving gives:
\[ X = +5 \]

- For **HClO2**:
- The equation is:
\[ X + 1 - 4 = 0 \quad \text{(2 oxygen atoms)} \]
- Solving gives:
\[ X = +3 \]

- For **HClO**:
- The equation is:
\[ X + 1 - 2 = 0 \quad \text{(1 oxygen atom)} \]
- Solving gives:
\[ X = +1 \]

3. **Determine the Acid Strength**:
- The strength of oxyacids is directly related to the oxidation state of the central atom (chlorine in this case). The higher the oxidation state, the stronger the acid.
- Based on our calculations:
- HClO4: +7 (strongest)
- HClO3: +5
- HClO2: +3
- HClO: +1 (weakest)

4. **Order of Acid Strength**:
- Therefore, the order of acid strength from weakest to strongest is:
\[ \text{HClO} < \text{HClO2} < \text{HClO3} < \text{HClO4} \]

### Final Answer:
The correct order of acid strength is: **HClO < HClO2 < HClO3 < HClO4**.