In the isolation of fluorine a number of difficulties were encountered. Which statements are correct:

Options

A. Fluorine reacts with moist glass vessels
B. Fluorine gas great affinity for hydrogen
C. Electrolysis of aqueous HF gives ozonized oxygen
D. the potential required for the discharge of the fluoride ions lowest

Answer

To determine which statements about the isolation of fluorine are correct, let's analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** F2 reacts with moist glass flasks or vessels.

**Explanation:** This statement is correct. Fluorine gas (F2) is highly reactive and can react with water (H2O) present in the moisture of the glass vessel to form hydrofluoric acid (HF). The reaction can be represented as:
\[ F_2 + H_2O \rightarrow 2HF \]
Furthermore, HF can react with silicon dioxide (SiO2) present in the glass to form silicon tetrafluoride (SiF4) and hydrogen gas (H2):
\[ SiO_2 + 4HF \rightarrow SiF_4 + 2H_2O \]

### Step 2: Analyze the second statement
**Statement:** Fluorine gas has a great affinity for hydrogen.

**Explanation:** This statement is true. Fluorine is one of the most electronegative elements and has a very high affinity for hydrogen. It readily reacts with hydrogen to form hydrogen fluoride (HF):
\[ F_2 + H_2 \rightarrow 2HF \]

### Step 3: Analyze the third statement
**Statement:** Electrolysis of aqueous HF gives ozonized oxygen.

**Explanation:** This statement is also true. When fluorine reacts with water, it can produce oxygen gas (O2) and HF. If excess water is present, it can lead to the formation of ozone (O3) as well:
\[ 2H_2O + 2F_2 \rightarrow O_2 + 4HF \]
In certain conditions, the reaction can yield ozone instead of just oxygen.

### Step 4: Analyze the fourth statement
**Statement:** The potential required for the discharge of fluorine ion is lowest.

**Explanation:** This statement is incorrect. The discharge potential for converting fluoride ions (F-) to fluorine gas (F2) is relatively high, approximately -2.86 volts. This means that a significant amount of energy is required to discharge fluorine ions, indicating that this statement is false.

### Step 5: Analyze the fifth statement
**Summary of correct statements:**
- The first three statements are correct (A, B, and C).
- The fourth statement is incorrect.

### Conclusion:
The correct statements regarding the isolation of fluorine are A, B, and C.