ECCB 303 EXAM 3 QUESTIONS WITH VERIFIED
ACCURATE ANSWERS
Combustion - Answers - a chemical chain reaction between fuel and O2 that is initiated
by and releases heat
What are the three requirements for combustion? (Fire triangle) - Answers - O2, Heat,
Fuel
Fuel - Answers - Plant biomass, organic (carbon based compounds), produced through
photosynthesis
What is the most abundant polymer in wildland fuel? - Answers - Cellulose (glucose
polymer)
What are other classes of organic compounds? - Answers - Lignin, waxes, fats,
terpenes
What is the electron acceptor in the combustion reaction? - Answers - Oxygen
Atmosphere percentages - Answers - O2 = 21%, N2 = 78%, Argon = 0.93% , CO2 =
0.04%
Pre and post industrial CO2 levels - Answers - 426ppm in 2024 and 280ppm pre
Conduction - Answers - Transfer of energy via fluid movement (liquid or gas)
Radiation - Answers - Transfer of energy via UV, visible, and infrared light
Conduction - Answers - Transfer of energy through solid matter
What is 'heat'? - Answers - Energy transfer due to a difference in temperature
What are the three preignition processes? - Answers - Dehydration, volatilization, and
pyrolysis (all endothermic)
Dehydration - Answers - Evaporation of water
Volatilization of extractives - Answers - State change of solid/liquid to gas for lipids/fats,
terpenes, waxes (involves organic compounds that easily turn to gas)
Pyrolysis - Answers - Thermal degradation of fuel and produces volatiles and tars, char,
and mineral ash
, What is mineral ash composed of? - Answers - Any C is typically carbonate CO3^2-, Ca
(7-33%), K (3-4%), Mg (1-2%), P (0.3-1.4%), Ma (0.3-1.3%), Na (0.2-0.5%)
Ignition - Answers - Transition between preignition and combustion and requires
temperature around 320 degree Celsius
Combustion - Answers - Exothermic, heat releasing, reactions
What is flaming combustion? - Answers - Oxidation of gases above the fuel
(volatilization)
What is smoldering/glowing combustion? - Answers - Oxidation of char on the surface
of the fuel
What is an example of smoldering/glowing combustion? - Answers - Cigars, going from
left to right of a lit cigar, mineral ash -> glowing char -> char -> pyrolysis -> fuel heating
to dehydration and CO2, H20, CO, and Nicotine (volatile extractive) go into lungs
Extinction - Answers - Transition point wherein heat produced is insufficient to maintain,
or propagate, combustion. Endothermic demands of preignition and ignition exceed
exothermic heat produced by combustion
Ground fire - Answers - fire that burns on the ground
Surface fire - Answers - fire that burns only undergrowth and leaf litter on the forest
floor.
Crown fire - Answers - extremely hot forest fire that burns ground vegetation and
treetops
Wildfire - Answers - a large fire that spreads quickly over a natural area
Fine fuel - Answers - less than 0.6cm
Flashy fuels
Ignite easily
Moisture fluctuates rapidly in response to weather
Coarse fuel - Answers - Greater than 0.6cm
Heavy fuels
More heat and time required to ignite
Longer lag in moisture response to weather
Aspects of topography - Answers - Slope, aspect, elevation
How does a shallow or no slope influence spread and intensity? - Answers - Slow
spread and slower intensity
ACCURATE ANSWERS
Combustion - Answers - a chemical chain reaction between fuel and O2 that is initiated
by and releases heat
What are the three requirements for combustion? (Fire triangle) - Answers - O2, Heat,
Fuel
Fuel - Answers - Plant biomass, organic (carbon based compounds), produced through
photosynthesis
What is the most abundant polymer in wildland fuel? - Answers - Cellulose (glucose
polymer)
What are other classes of organic compounds? - Answers - Lignin, waxes, fats,
terpenes
What is the electron acceptor in the combustion reaction? - Answers - Oxygen
Atmosphere percentages - Answers - O2 = 21%, N2 = 78%, Argon = 0.93% , CO2 =
0.04%
Pre and post industrial CO2 levels - Answers - 426ppm in 2024 and 280ppm pre
Conduction - Answers - Transfer of energy via fluid movement (liquid or gas)
Radiation - Answers - Transfer of energy via UV, visible, and infrared light
Conduction - Answers - Transfer of energy through solid matter
What is 'heat'? - Answers - Energy transfer due to a difference in temperature
What are the three preignition processes? - Answers - Dehydration, volatilization, and
pyrolysis (all endothermic)
Dehydration - Answers - Evaporation of water
Volatilization of extractives - Answers - State change of solid/liquid to gas for lipids/fats,
terpenes, waxes (involves organic compounds that easily turn to gas)
Pyrolysis - Answers - Thermal degradation of fuel and produces volatiles and tars, char,
and mineral ash
, What is mineral ash composed of? - Answers - Any C is typically carbonate CO3^2-, Ca
(7-33%), K (3-4%), Mg (1-2%), P (0.3-1.4%), Ma (0.3-1.3%), Na (0.2-0.5%)
Ignition - Answers - Transition between preignition and combustion and requires
temperature around 320 degree Celsius
Combustion - Answers - Exothermic, heat releasing, reactions
What is flaming combustion? - Answers - Oxidation of gases above the fuel
(volatilization)
What is smoldering/glowing combustion? - Answers - Oxidation of char on the surface
of the fuel
What is an example of smoldering/glowing combustion? - Answers - Cigars, going from
left to right of a lit cigar, mineral ash -> glowing char -> char -> pyrolysis -> fuel heating
to dehydration and CO2, H20, CO, and Nicotine (volatile extractive) go into lungs
Extinction - Answers - Transition point wherein heat produced is insufficient to maintain,
or propagate, combustion. Endothermic demands of preignition and ignition exceed
exothermic heat produced by combustion
Ground fire - Answers - fire that burns on the ground
Surface fire - Answers - fire that burns only undergrowth and leaf litter on the forest
floor.
Crown fire - Answers - extremely hot forest fire that burns ground vegetation and
treetops
Wildfire - Answers - a large fire that spreads quickly over a natural area
Fine fuel - Answers - less than 0.6cm
Flashy fuels
Ignite easily
Moisture fluctuates rapidly in response to weather
Coarse fuel - Answers - Greater than 0.6cm
Heavy fuels
More heat and time required to ignite
Longer lag in moisture response to weather
Aspects of topography - Answers - Slope, aspect, elevation
How does a shallow or no slope influence spread and intensity? - Answers - Slow
spread and slower intensity
