Rate of flammability CH4

Rate of flammability CH4

• A. 0-5%
• B. 15-30%
• C. 1-4%
• D. 5-15%

Answer: (D)

The main idea is the flammable limits of methane in air—the concentration range that can sustain combustion. Methane will ignite only when its concentration in air is within a certain window. For CH4, this window is about 5% to 15% by volume in air. Below roughly 5%, the mixture is too lean to burn; above roughly 15%, it’s too rich to support flame. So the range 5-15% best represents the flammable interval. The other options fall outside that window, either being too lean or too rich to sustain combustion.

The main idea is the flammable limits of methane in air—the concentration range that can sustain combustion. Methane will ignite only when its concentration in air is within a certain window. For CH4, this window is about 5% to 15% by volume in air. Below roughly 5%, the mixture is too lean to burn; above roughly 15%, it’s too rich to support flame. So the range 5-15% best represents the flammable interval. The other options fall outside that window, either being too lean or too rich to sustain combustion.