Chapter 14 Fire Investigation

Question 0

Oxidation

Answer 0

The combination of oxygen with other substances to produce new substances

Question 1

Modus operandi

Answer 1

An offender’s pattern of operation

Question 2

Energy

Answer 2

The ability or potential of a system or material to do work.

Question 3

Combustion

Answer 3

Rapid combination of oxygen with another substance, accompanied by production or noticeable heat and light

Question 4

Exothermic reaction

Answer 4

A chemical transformation in which heat energy is liberated

Question 5

Heat of combustion

Answer 5

The heat liberated during combustion

Question 6

Endothermic reaction

Answer 6

A chemical transformation in which heat energy is absorbed from the surroundings

Question 7

Ignition temperature

Answer 7

The minimum temperature at which a fuel spontaneously ignites

Question 8

Flash point

Answer 8

The minimum temperature at which a liquid fuel produces enough vapor to burn

Question 9

Pyrolysis

Answer 9

The decomposition of solid organic matter by heat

Question 10

Flammable range

Answer 10

The entire range of possible gas or vapor fuel concentrations in air that are capable of burning

Question 11

Glowing combustion

Answer 11

Combustion on the surface of a solid fuel in the absence of heat high enough to pyrolyze the fuel

Question 12

Spontaneous combustion

Answer 12

A fire caused by a natural heat-producing process in the presence of sufficient air and fuel

Question 13

Accelerant

Answer 13

Any material used to start or sustain a fire

Question 14

Hydrocarbon

Answer 14

Any compound consisting of only carbon and hydrogen

Question 15

Chemical equation for the burning of methane gas

Answer 15

CH_4 + 2O_2 —> CO_2 + 2H_2O

Methane + oxygen yields carbon dioxide + water

Question 16

Chemical equation for rust

Answer 16

4Fe + 3O_2 —> 2Fe_2O_3

Iron + oxygen yields iron oxide

Question 17

Conduction

Answer 17

Movement of heat through a solid object

Question 18

Radiation

Answer 18

The transfer of heat energy from a heated surface to a cooler surface by electromagnetic radiation

Question 19

Convection

Answer 19

The transfer of heat energy by movement of molecules withon liquid or gas

Question 20

True or false: the absence of chemical residues always rules out the possibility of arson.

Answer 20

False

Question 21

The combination of oxygen with other substances to produce new chemical products is called ___________.

Answer 21

Oxidation

Question 22

True or false: all oxidation reactions produce noticeable quantities of heat and light.

Answer 22

False

Question 23

________ is the capacity for doing work.

Answer 23

Energy

Question 24

Burning methane for the purpose steam in order to drive a turbine is an example of converting _______ energy to ________ energy.

Answer 24

Absorb; liberate

Question 25

Molecules must (absorb; liberate) energy to break their bonds and (absorb; liberate) energy to break their bonds are reformed.

Answer 25

Absorb; liberate

Question 26

Reactions that liberate heat are said to be ______.

Answer 26

Exothermic

Question 27

A chemical reaction in which heat is absorbed from the surroundings is said to be _______.

Answer 27

Endothermic

Question 28

The minimum temperature at which fuel burns is known as the _________ temperature.

Answer 28

Ignition

Question 29

The lowest temperature at which a liquid fuel process enough vapor to burn is the _______.

Answer 29

Flash point

Question 30

__________ is phenomenon in which a fuel burns without the presence of a flame.

Answer 30

Glowing combustion

Question 31

The lowest temperature at which a liquid fuel produces enough vapor to burn is the ________.

Answer 31

Flash point

Question 32

__________ describes a fire caused by a natural heat-producing process.

Answer 32

Spontaneous combustion

Question 33

Electrons and atoms within a solid object exposed to heat collide with one another, causing movement of heat through the object is called __________.

Answer 33

Conduction

Question 34

In a process known as _______, a heated surface emits electromagnetic radiation of various wavelengths that moves in a straight line from one surface to another, helping the fire to spread throughout a structure.

Answer 34

Radiation

Question 35

True or false: an immediate search of a fire scene can commerce without obtaining a search warrant.

Answer 35

True

Question 36

True or false: the probable origin of a fire is most likely closest to the lowest point that shows the most intense characteristics of burning.

Answer 36

True

Question 37

________ containers must be used to package all materials suspected of containing hydrocarbon residues.

Answer 37

Airtight

Question 38

The identity of a volatile petroleum residue is determined by the (size; pattern) of its gas chromatogram.

Answer 38

Pattern

Question 39

True or false: a forensic analyst typically compares the gas chromatographic pattern generated from a fire-scene sample to a library of patterns in order to identify the accelerant.

Answer 39

True

Question 40

Complex chromatographic patterns can be simplified by passing the continents emerging from the gas chromatographic column through a(n) _______.

Answer 40

Mass spectrometer

Question 41

Indicate which method of heat transfer is most likely to be responsible for each:
A. Ignition of papers in the room where a fire starts
B. ignition of electrical wiring in a room adjoining the fire’s point or origin.
C. Ignition of roof timbers
D. Ignition of a neighboring house

Answer 41

A. Radiation
B. conduction
C. Convection
D. Radiation