Chapter Test 4 (IFSTA 7th Edition) SOLUTION 2023//2024

Chapter Test 4 (IFSTA 7th Edition) SOLUTION 2023//2024 Fires involve a heat-producing chemical reaction between fuel and: (117) [4.3.11] A. a catalyst. B. an oxidizer. C. free radicals. D. a reducing agent. - ANSWER B. an oxidizer When a substance changes from one type of matter into another, such as two or more substances combining to form compounds, the substance undergoes a: (118) [4.3.11] A. dissolution. B. metamorphosis. C. chemical reaction. D. physiological change. - ANSWER C. chemical reaction Which statement about energy and combustion is accurate? (120) [4.3.11] A. A fuel's chemical energy is the result of rapid vibrations in the molecules. B. Chemical and physical changes almost never involve an exchange of energy. C. A fuel's potential energy releases during combustion and converts to kinetic energy. D. Chemical changes involve an exchange of energy; physical changes involve no energy exchange. - ANSWER C. A fuel's potential energy releases during combustion and converts to kinetic energy. Which element of the fire tetrahedron is included to explain flaming (gas-phase) combustion? (120) [4.3.11] A. Fuel B. Heat C. Oxygen D. Chemical chain reaction - ANSWER D. Chemical chain reaction What occurs when a mixture of fuel and oxygen encounter an external heat source with sufficient heat or thermal energy to start the combustion reaction? (120) [4.3.11] A. Autoignition B. Piloted ignition C. Kinetic ignition D. Sustained ignition - ANSWER B. Piloted ignition The minimum temperature at which a fuel in the air must be heated in order to start selfsustained combustion is known as the: (122) [4.3.11] A. autoignition temperature (AIT). B. piloted ignition temperature (PIT). C. lower explosive (flammable) limit (LEL). D. upper explosive (flammable) limit (UEL). - ANSWER A. autoignition temperature (AIT). What causes flaming combustion to occur? (123) [4.3.11] A. A solid fuel encounters an open flame and entrain enough air to ignite. B. A gaseous fuel encounters an external heat source and experience piloted ignition. C. A gaseous fuel mixes with an adequate amount of oxygen and heats to ignition temperature. D. A solid fuel mixes with an adequate amount of liquid fuel to be able to sustain an open burning flame. - ANSWER C. A gaseous fuel mixes with an adequate amount of oxygen and heats to ignition temperature. What is the cause of most fire deaths? (124) [4.3.10, 4.3.11] A. Injuries caused by falling materials or structural collapse B. Exposure to toxic gases found in smoke and/or lack of oxygen C. Exposure to extreme heat and/or contact with flames and hot surfaces D. Accidental injuries sustained during escape and/or evacuation procedures - ANSWER B. Exposure to toxic gases found in smoke and/or lack of oxygen Which statement about the dangers of products of combustion is accurate? (124) [4.3.11] A. Visible smoke presents the greatest inhalation danger. B. Low oxygen concentrations alone can result in hypoxia or death. C. Toxic products of combustion are released only during the combustion reaction. D. The toxic effects of smoke inhalation are the result of the interaction between carbon monoxide and heat. - ANSWER B. Low oxygen concentrations alone can result in hypoxia or death. Which product of combustion acts as a chemical asphyxiant by excluding oxygen from the blood, leading to hypoxia of the brain and tissues? (124-125) [4.3.11] A. Carbon dioxide (C02) B. Carbon monoxide (CO) C. Aerosolized fuel particles D. Hydrogen cyanide (HCN) - ANSWER B. Carbon monoxide (CO) Hydrogen cyanide (HCN) is a product of combustion that: (126) [4.3.11] A. is equally as toxic as carbon monoxide (CO). B. is released when wood and other natural materials are burned. C. targets the brain after being inhaled, ingested, or absorbed into the body. D. acts as a respiratory stimulant, increasing respiratory rate and increasing oxygen to blood cells. - ANSWER C. targets the brain after being inhaled, ingested, or absorbed into the body How does a compartment fire affect pressure in and around gases in the compartment? (127) [4.3.11] A. Heat from a fire increases the pressure of the surrounding gases. B. Gases move from areas of lower pressure to areas of higher pressure. C. At standard temperature and atmospheric pressure, gases circulate at a steady, uniform rate. D. Significant differences in pressure, typically 10 kPa or greater, are required to cause movement of gases in a