Which of the following oxyacids of chlorine is formed on shaking chlorine water with freshly precipitated yellow oxide of mercury?

Options

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

Explanation

To solve the question regarding which oxyacid of chlorine is formed when chlorine water is shaken with freshly precipitated yellow oxide of mercury, we can follow these steps:

### Step 1: Understand the Reactants
- We have chlorine water (Cl2 dissolved in water) and freshly precipitated yellow oxide of mercury (HgO).

### Step 2: Identify the Reaction
- When chlorine (Cl2) reacts with mercury oxide (HgO) in the presence of water, a chemical reaction occurs.

### Step 3: Write the Reaction Equation
- The reaction can be represented as:
\[ \text{HgO} + \text{Cl}_2 + \text{H}_2\text{O} \rightarrow \text{HgCl}_2 + \text{HClO} \]
- Here, mercuric chloride (HgCl2) and hypochlorous acid (HClO) are formed.

### Step 4: Identify the Oxyacid Formed
- From the reaction, we see that the oxyacid of chlorine formed is hypochlorous acid (HClO).

### Step 5: Conclusion
- Therefore, the oxyacid of chlorine formed on shaking chlorine water with freshly precipitated yellow oxide of mercury is **hypochlorous acid (HClO)**.

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