FE Extinguishing Agent Properties & Chemistry

Question 1

What is the primary extinguishing mechanism of ABC dry chemical agents such as monoammonium phosphate?

Accepted Answer

Interrupting the chemical chain reaction of combustion

Answer

Cooling the fuel surface below ignition temperature

Answer

Diluting oxygen concentration below 15%

Answer

Forming a physical barrier over the fuel

Question 2

Which extinguishing agent is electrically non-conductive and leaves virtually no residue after discharge?

Accepted Answer

Carbon dioxide (CO2)

Answer

Dry chemical (monoammonium phosphate)

Answer

AFFF foam

Answer

Wet chemical potassium acetate

Question 3

Purple-K dry chemical extinguishing agent contains which primary chemical compound?

Accepted Answer

Potassium bicarbonate

Answer

Monoammonium phosphate

Answer

Sodium bicarbonate

Answer

Potassium chloride

Question 4

Carbon dioxide (CO2) extinguishes fires primarily by which two mechanisms?

Accepted Answer

Oxygen displacement and cooling

Answer

Chemical chain interruption and fuel removal

Answer

Saponification and smothering

Answer

Emulsification and dilution

Question 5

Halon 1211 (bromochlorodifluoromethane) is classified as what type of extinguishing agent?

Accepted Answer

Halogenated agent

Answer

Wet chemical agent

Answer

Inert gas agent

Answer

Dry powder agent

Question 6

What is the approximate specific gravity of carbon dioxide gas compared to air at standard conditions?

Accepted Answer

1.5 (heavier than air)

Answer

0.7 (lighter than air)

Answer

1.0 (same weight as air)

Answer

2.5 (much heavier than air)

Question 7

Sodium bicarbonate dry chemical is rated for use on which fire classes?

Accepted Answer

Class B and C fires only

Answer

Class A and B fires only

Answer

Class A, B, and C fires

Answer

Class D fires only