HgO is analysed by reaction with iodide and them titrating with an acid. The equivalent mass of `HgO` in `H_(2)O+HgO+4I^(-)rarrHgI_(4)^(-2)+2OH^(-)`

Answer

To find the equivalent mass of HgO in the given reaction, we will follow these steps:

### Step 1: Write the balanced chemical equation
The reaction given is:
\[ \text{HgO} + \text{H}_2\text{O} + 4\text{I}^- \rightarrow \text{HgI}_4^{2-} + 2\text{OH}^- \]

### Step 2: Identify the number of moles of hydroxide ions produced
From the balanced equation, we see that 1 mole of HgO produces 2 moles of OH⁻ ions.

### Step 3: Relate hydroxide ions to protons
Since 2 moles of OH⁻ ions are produced, this is equivalent to 2 moles of H⁺ ions (as OH⁻ can neutralize H⁺). Therefore, 1 mole of HgO can react with 2 moles of H⁺.

### Step 4: Determine the equivalent mass
The equivalent mass of a substance is defined as the mass that reacts with or supplies 1 mole of H⁺ ions. Since 1 mole of HgO reacts with 2 moles of H⁺, the equivalent mass of HgO can be calculated as follows:

1. Calculate the molar mass of HgO:
- Molar mass of Hg = 200.59 g/mol
- Molar mass of O = 16.00 g/mol
- Molar mass of HgO = 200.59 + 16.00 = 216.59 g/mol

2. Since 1 mole of HgO provides 2 equivalents (because it reacts with 2 moles of H⁺), the equivalent mass (E) can be calculated using the formula:
\[ E = \frac{\text{Molar mass}}{\text{Number of equivalents}} = \frac{216.59 \text{ g/mol}}{2} = 108.295 \text{ g/equiv} \]

### Step 5: Conclusion
The equivalent mass of HgO in the given reaction is approximately 108.30 g/equiv.

---