Question

The refrigerant R-11 is

• A. Carbon dioxide
• B. Trichloro monofluoro methane
• C. Monochloro trifluoro methane
• D. Trichloro trifluoro ethane

Hint:

R-11 means 1 carbon, 0 hydrogen, 1 fluorine, so the 3 remaining bonds hold chlorine: CCl3F.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Refrigerants are numbered by a system. For a refrigerant of the methane series, the number R-XY has the digits tens = number of hydrogen atoms plus 1, units = number of fluorine atoms. The carbon number is one more than the hundreds digit.

Step 2: Key Approach:
For R-11, the number is written as 011. So hundreds digit = 0, tens digit = 1, units digit = 1.

Step 3: Detailed Explanation:
Carbon atoms = 0 + 1 = 1, so it is a methane derivative.
Hydrogen atoms = 1 - 1 = 0.
Fluorine atoms = 1.
Methane has 4 bonds on carbon, so chlorine atoms = 4 - 0 - 1 = 3.
The formula is CCl3F. Its name is trichloro monofluoro methane.

Step 4: Why the other options are wrong.
Carbon dioxide is R-744.
Monochloro trifluoro methane, CClF3, is R-13.
Trichloro trifluoro ethane, C2Cl3F3, is R-113.

Final Answer:
R-11 is trichloro monofluoro methane. This is option (B).