Rate of flammability C3H8

Rate of flammability C3H8

• A. 2-10%
• B. 5-15%
• C. 10-20%
• D. 1-3%

Answer: (A)

Propane has a flammable vapor range in air defined by its lower and upper flammable limits. Below about 2% in air the mixture is too lean to ignite, and above about 10% it’s too rich to support combustion. Between roughly 2% and 10% propane in air, ignition is possible. Therefore, the flammability range is about 2-10%, which is why that option is the best fit (LFL ≈ 2.1%, UFL ≈ 9.5%). Other ranges either miss the lower limit or the upper limit, so they don’t match the actual propellant limits.

Propane has a flammable vapor range in air defined by its lower and upper flammable limits. Below about 2% in air the mixture is too lean to ignite, and above about 10% it’s too rich to support combustion. Between roughly 2% and 10% propane in air, ignition is possible. Therefore, the flammability range is about 2-10%, which is why that option is the best fit (LFL ≈ 2.1%, UFL ≈ 9.5%). Other ranges either miss the lower limit or the upper limit, so they don’t match the actual propellant limits.