1|Page
CHAPTER 4 (IFSTA 7TH EDITION) QUESTIONS
WITH CORRECT ANSWERS
The minimum temperature at which a liquid gives off sufficient vapors to ignite,
but not sustain combustion is its: (139) [4.3.10, 4.3.11]
A. Flash point
B. Vapor pressure
C. Specific gravity
D. Degree of solubility-correct-answer-A. flash point.
What may occur if water is added to a burning liquid that is less dense than
water? (139) [4.3.10]
A. The fuel's rate of vaporization will decrease due to the increased water
pressure.
B. The water may disperse the burning liquid instead of extinguishing it.
C. The liquid fuel may vaporize much more rapidly as it draws thermal energy
from the water.
D. The water will mix with the burning liquid and become less effective at
extinguishing the fire.-correct-answer-B. The water may disperse the burning
liquid instead of extinguishing it.
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When solid fuels are heated, they begin to ______ and release fuel gases and
vapors. (139) [4.3.10, 4.3.11]
A. melt
B. pyrolize
C. hypoxilize
D. evaporate-correct-answer-B. pryolize
Sawdust ignites more easily than a log because the sawdust has a higher: (140)
[4.3.11]
A. pyrolysis point.
B. surface-to-mass ratio.
C. fuel thickness proportion.
D. flammable (explosive) range.-correct-answer-B. surface-to-mass ratio
In most compartment fires, the energy release in fire is directly proportional to
the: (140) [4.3.11]
A. thermal conductivity of the fuel.
B. amount of fuel available for combustion.
C. ambient temperature of the environment.
D. amount of oxygen available for combustion.-correct-answer-D. amount of
oxygen available for combustion.
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Materials that burn at normal oxygen levels will burn more intensely in ______
atmospheres. (143) [4.3.11]
A. flaming
B. nonflaming
C. oxygen-enriched
D. oxygen-deficient-correct-answer-C. oxygen-enriched
Combustion can occur within a range of concentration of fuel vapor and air; this
range is referred to as the: (143) [4.3.11]
A. vapor pressure range.
B. surface to mass range.
C. flammable (explosive) range.
D. oxidation (combustion) range.-correct-answer-C. flammable (explosive) range.
How does the self-sustained chemical reaction influence the oxidation reaction in
flaming combustion? (144) [4.3.11]
A. Increases the speed of the oxidation reaction
B. Decreases the types of products of combustion released
C. Decreases the temperature required for the oxidation reaction
D. Increases the ratio of complete to incomplete combustion of fuel-correct-
answer-A. Increases the speed of the oxidation reaction
CHAPTER 4 (IFSTA 7TH EDITION) QUESTIONS
WITH CORRECT ANSWERS
The minimum temperature at which a liquid gives off sufficient vapors to ignite,
but not sustain combustion is its: (139) [4.3.10, 4.3.11]
A. Flash point
B. Vapor pressure
C. Specific gravity
D. Degree of solubility-correct-answer-A. flash point.
What may occur if water is added to a burning liquid that is less dense than
water? (139) [4.3.10]
A. The fuel's rate of vaporization will decrease due to the increased water
pressure.
B. The water may disperse the burning liquid instead of extinguishing it.
C. The liquid fuel may vaporize much more rapidly as it draws thermal energy
from the water.
D. The water will mix with the burning liquid and become less effective at
extinguishing the fire.-correct-answer-B. The water may disperse the burning
liquid instead of extinguishing it.
,2|Page
When solid fuels are heated, they begin to ______ and release fuel gases and
vapors. (139) [4.3.10, 4.3.11]
A. melt
B. pyrolize
C. hypoxilize
D. evaporate-correct-answer-B. pryolize
Sawdust ignites more easily than a log because the sawdust has a higher: (140)
[4.3.11]
A. pyrolysis point.
B. surface-to-mass ratio.
C. fuel thickness proportion.
D. flammable (explosive) range.-correct-answer-B. surface-to-mass ratio
In most compartment fires, the energy release in fire is directly proportional to
the: (140) [4.3.11]
A. thermal conductivity of the fuel.
B. amount of fuel available for combustion.
C. ambient temperature of the environment.
D. amount of oxygen available for combustion.-correct-answer-D. amount of
oxygen available for combustion.
, 3|Page
Materials that burn at normal oxygen levels will burn more intensely in ______
atmospheres. (143) [4.3.11]
A. flaming
B. nonflaming
C. oxygen-enriched
D. oxygen-deficient-correct-answer-C. oxygen-enriched
Combustion can occur within a range of concentration of fuel vapor and air; this
range is referred to as the: (143) [4.3.11]
A. vapor pressure range.
B. surface to mass range.
C. flammable (explosive) range.
D. oxidation (combustion) range.-correct-answer-C. flammable (explosive) range.
How does the self-sustained chemical reaction influence the oxidation reaction in
flaming combustion? (144) [4.3.11]
A. Increases the speed of the oxidation reaction
B. Decreases the types of products of combustion released
C. Decreases the temperature required for the oxidation reaction
D. Increases the ratio of complete to incomplete combustion of fuel-correct-
answer-A. Increases the speed of the oxidation reaction
