Which of the following statements is false

Options

A. `CaOCl_(2)` gives `OH^(-),Cl^(-)` and `Ocl^(-)` in aqueous solution
B. Diamond and graphite are allotrops of carbon
C. Bleaching action of `Cl_(2)` in moist condition is not permanent
D. Calomel is `Hg_(2)Cl_(2)`

Explanation

To determine which statement is false among the given options, let's analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** CaOCl2 (Bleaching powder) gives OH-, Cl-, and OCl- in an equal solution.

**Analysis:**
- When bleaching powder (Ca(OCl)2) is dissolved in water, it dissociates into calcium ions (Ca²⁺) and hypochlorite ions (OCl⁻).
- The reaction can be represented as:
\[ Ca(OCl)2 \rightarrow Ca^{2+} + 2OCl^{-} \]
- Additionally, in water, hypochlorite can produce hydroxide ions (OH⁻) due to the equilibrium established in the solution:
\[ OCl^{-} + H_2O \rightleftharpoons HOCl + OH^{-} \]
- However, the statement claims that OH-, Cl-, and OCl- are all present in equal amounts, which is not accurate. The presence of Cl- is not a direct result of dissolving bleaching powder; instead, it is formed under different conditions (like the presence of hydrochloric acid).

### Conclusion for Step 1:
The first statement is misleading because it suggests equal concentrations of OH-, Cl-, and OCl-, which is not true.

### Step 2: Analyze the second statement
**Statement:** Diamond and graphite are allotropes of carbon.

**Analysis:**
- This statement is true. Both diamond and graphite are well-known allotropes of carbon, differing in their structure and properties.

### Step 3: Analyze the third statement
**Statement:** The bleaching action of Cl2 in moist conditions is not permanent.

**Analysis:**
- This statement is also true. Chlorine (Cl2) can bleach materials, but its bleaching action is often not permanent because it can react with organic materials and be consumed in the process.

### Step 4: Analyze the fourth statement
**Statement:** K2HgCl4 contains Hg2Cl2.

**Analysis:**
- This statement is false. K2HgCl4 is actually potassium tetrachloromercurate(II) and does not contain the diatomic cation Hg2^2+ (which is present in Hg2Cl2).

### Final Conclusion:
The false statement among the options is the first statement regarding the dissociation of CaOCl2 and the presence of OH-, Cl-, and OCl- in equal amounts.

### Summary of the False Statement:
The false statement is: "CaOCl2 (Bleaching powder) gives OH-, Cl-, and OCl- in equal solution."

---