Which one is correct?

Options

A. Freon-14 is `CF_4`, Freon-13 is `CF_3Cl` , Freon-12 is `CF_2Cl_2` and Freon-11 is `CFCl_3`.
B. Freons are chlorofluorocarbons.
C. Freon are used as refrigerants.
D. All of these.

Answer

To determine which statement about Freon is correct, we can analyze each option step by step.

### Step 1: Analyze the First Option
The first option states:
- Freon-14 is CF4
- Freon-13 is CF3Cl
- Freon-12 is CF2Cl2
- Freon-11 is CFCl3

**Solution:**
- Freon-14 (CF4) is indeed correct; it is also known as tetrafluoromethane.
- Freon-13 (CF3Cl) is correct; it is known as trichlorofluoromethane.
- Freon-12 (CF2Cl2) is correct; it is known as dichlorodifluoromethane.
- Freon-11 (CFCl3) is correct; it is known as trichlorofluoromethane.

Thus, the first option is correct.

### Step 2: Analyze the Second Option
The second option states that Freons are chlorofluorocarbons.

**Solution:**
Freons are indeed a class of compounds known as chlorofluorocarbons (CFCs). This statement is correct.

### Step 3: Analyze the Third Option
The third option states that Freon is used as a refrigerant.

**Solution:**
Freons are widely used as refrigerants in air conditioning and refrigeration systems. This statement is also correct.

### Step 4: Analyze the Fourth Option
The fourth option states that all of these statements are correct.

**Solution:**
Since we have established that the first three options are correct, the fourth option, which claims that all of these are correct, is also correct.

### Final Answer
Thus, the correct answer is:
**D) All of these.**

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