book 83 fire chemistry

Question 1

Liquids having a flash point at or above 100 degrees F.

Answer 1

Combustible liquids

Question 2

Rapid oxidation of a substance accompanied by the release of energy usually in the form of heat and light.

Answer 2

Fire

Question 3

The lowest temperature of a liquid in an open container at which vapors evolve fast enough to support continuous combustion.

Answer 3

Fire Point

Question 4

The term lower flammable limits (LFL) describes the minimum concentration of vapor -to -air below which propagation will not occur in the presence of an ignition source. The “upper flammable limit” (UFL) is the maximum vapor-to-air concentration above which propagation of flame will not occur.

Answer 4

Flammable limits

Question 5

Liquids having a flash point below 100 degrees F.

Answer 5

Flammable liquids

Question 6

The minimum temperature at which a liquid gives off vapors in sufficient concentrations to form an ignitable mixture with air near the surface of the liquid.

Answer 6

Flash point

Question 7

A form, of energy associated with the motion of atoms and molecules.

Answer 7

Heat

Question 8

The amount of heat released during the complete oxidation of a substance.

Answer 8

Heat of combustion

Question 9

The minimum temperature to which a substance must be heated in air in order to initiate or cause combustion, independent of the heating element or source. The ignition temperature of ordinary combustibles is between 300 and 1000 degrees. F

Answer 9

Ignition temperature

Question 10

As a substance burns, it mixes with oxygen and produces heat.

Answer 10

Oxidation

Question 11

The ratio of the weight of a solid or liquid substance to the weight of an equal volume of water.

Answer 11

Specific gravity

Question 12

The quantity of heat concentration. The intensity of heat is measured in degrees (Fahrenheit or Celsius).

Answer 12

Temperature

Question 13

The weight per unit volume of a pure gas or vapor. In fire protection, vapor density is reported in terms of the ratio of the relative weight of a volume of vapor to the weight of an equal volume of air under the same conditions of temperature and pressure.

Answer 13

Vapor density

Question 14

A vapor denisty less than 1.0 indicates a vapor is ____ than air.

Answer 14

lighter

Question 15

A vapor density more than 1.0 indicates a vapor ______ than air.

Answer 15

heavier

Question 16

Heat , fuel, oxygen equals?

Answer 16

The fire triangle

Question 17

Heat , Fuel , Oxygen and Uninhibited chain reaction among all parts of the ________

Answer 17

Fire tetrahedron

Question 18

The Chemical decomposition of matter through the action of heat.

Answer 18

Pyrolysis

Question 19

The transfer of heat from one object to another through direct physical contact.

Answer 19

Conduction

Question 20

The transfer of heat by some circulating medium (liquid or gas). This is the form of heat transfer most RESPONSIBLE for fire spread in structural fires.

Answer 20

convection

Question 21

Example; The spreading of fire from lower to upper structural areas when upper areas become heated to their ignition temperature is ____.

Answer 21

Convection

Question 22

The transfer of heat as energy traveling through space or materials as waves.

Answer 22

Radiation

example: exposure problems in large fires…

Question 23

Although actual flame temperatures can reach 1000 degrees F. temperatures in the surrounding area are not greatly increased. There is free burning with open flame. Oxygen in the area remains new 21%. Thermal updrafts causes heat to accumulate at the higher portions of the area.

Answer 23

Incipient phase (growth)

Question 24

Fully developed
air from surrounding atmosphere is drawn into the fire fire.
Mushrooming may take place and flame is present. Oxygen content of area is usually reduced to 16%-18% Fire gases which may be present are carbon, carbon monoxide, carbon dioxide, water, sulfur dioxide,
Flashover frequently occurs during this phase.

Answer 24

Free burning phase.

Question 25

Decay: Free burning may cease in the fire area. Area fills with dense smoke. Oxygen may drop below 15%. Temperature may reach 1000 degrees F. thought the area. Improper /uncontrolled air admission may result in "backdraft"

Answer 25

Smoldering phase

Question 26

A ________ is defined as an explosion or rapid burning of heated fire gases resulting from the introduction of oxygen when air is admitted into a building heavily charged by smoke from a fire which has depleted the oxygen content of a building.

Answer 26

Backdraft

Question 27

Backdraft indicators:

Answer 27

``` Heavy smoke conditions on arrival Lack of Visible flame Improper method of entering a structure may cause a backdraft Movement of smoke prior to explosion Structure may appear to breathe Whistle, jet or train sound ```

Question 28

_____ is the stage of the fire when all combustibles in an area have become heated to their ignition temperature, then ignite simultaneously.

Answer 28

Flashover

Question 29

Fire resistive, structural elements in Type ___ fire resistive buildings shall be of steel, iron , concrete, or masonry. Walls and permanent partitions shall be of noncombustible fire-resistive construction except that permanent non-bearing partitions may have fire -retardant wood.

Answer 29

Type 1

Question 30

Type ____ Noncombustible /fire-resistive , one-hour or no-hour construction. construction in which walls, partitions, and structural members are of noncombustible material but do not qualify as type 1 fire-resistive

Answer 30

Type ll

Question 31

Type _____ Ordinary construction , in which exterior bearing walls or bearing partitions of exterior wall are of noncombustible materials and have a minimum hourly fire-resistive rating. Wood allowed for interior use.

Answer 31

Type lll

Question 32

Type ____ heavy timber construction where exterior bearing and non-bearing walls are noncombustible and have a minimum fire-resistive rating of four hours. Colums, beams and girder are commonly heavy timber with wood floors and roof construction built without concealed spaces..

Answer 32

Type lV

Question 33

Type ______ Wood frame construction in which exterior walls, bearing walls, partitions, floors and roofs as well as their supports are wholly or partly wood or other combustibles.

Answer 33

Type V

Question 34

The weight of the building and any equipment permanently attached or built-in

Answer 34

dead load

Question 35

Any load other than a dead load. _____ loads vary with intended or actual use of the structure. Examples of common _____ loads ae occupants, storage, and furnishings.

Answer 35

Live loads

Question 36

_____loads which are delivered in a short period of time. ______loads may be more harmful when supported as dead or live loads. Examples are explosions, wind and earthquakes.

Answer 36

impact load

Question 37

_____ loads: the total number of BTU's which might be evolved during a fire in the building or area under consideration and the rate at which the heat will be evolved. Occupancy type has a direct relationship to fire load and generally dictates the possible _____ load

Answer 37

Fire load

Question 38

Conventional or ordinary construction consists of a ridge board and rafters from the ridge board down to and across the outside walls (studs). Ridge and rafters are usually 2 by6 inches or larger. Rafters are usually 16 inches to 24 inches on center. Additional support is provided by collar beams and ceiling joists. Roofs are constructed in semi-flat to steep pitches.

Answer 38

Gable roof

Question 39

Similar to gable roof. Ends of roof terminate in hip. Conventional or ordinary construction consist of ride pole and hip rafters rom the ridge board down to and across the corners at the outside walls. valley rafters are utilized where two roof lines are joined together. Ridge and rafters are usually 2 by 6 inches or lager. Rafters are usually 16 to 24 inches on center.

Answer 39

Hip roof

Question 40

Wood joists (rafters) of various sizes laid across the outside walls or outside walls to interior walls or structural supports Joist may also be suspended by metal hangers. Joist are covered with 1 by 6 inch sheathing or plywood and composition roofing material.

Answer 40

Flat roof

Question 41

wooden truss members constructed from 2 by 12 inch lumber with sloping ends. Usually a heavy grade construction. Metal tie rods may be used vertically for additional support. Joists are 2 by 6 inches and 2 by 8 inches covered with 1 by 6 inch sheathing and composition roofing mater.

Answer 41

Bridge truss roof

Question 42

_____ roff with ties rods and turnbuckles offering lateral support. Tie rods with turnbuckles are used below each arch member to support the exterior walls. Tie rods may pass through exterior walls to an outside plate facilitating identification. Tension is maintained by the turnbuckles top chords of arch members may utilize laminated 2 by 12 or larger. Two by 10 inch rafters are covered by 1 by 6 inch sheathing and composition roofing material.

Answer 42

Bowstring are roof

Question 43

Usually large size (2 by 12, 2 by 14 inch) wooden members utilized to construct truss arch. Some arches have multiple laminated beams to form one arch. Rafters ( 2 by 10 inch or larger) are covered with 1 by 6 inch: sheathing and composition roofing material.

Answer 43

Ribbed ( trussed) arch roof

Question 44

The amount of head required to raise the temperature of one pound of water one degree Fahrenheit (measure at 60 degrees F)

Answer 44

British Thermal Unit (BTU)