Chapter 16 - Fire/Explosion

Question 1

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

Answer 1

oxidation

Question 2

True or False: All oxidation reactions yield carbon dioxide and water as products.

Answer 2

False

Question 3

_____ is the capacity for doing work.

Answer 3

energy

Question 4

Burning methane to heat water and thus produce steam for the purpose of driving a turbine is an example of converting _____ energy to _____ energy to _____ energy.

Answer 4

chemical;
heat;
mechanical

Question 5

The quantity of heat evolved from a chemical reaction arises out of the _____ and of chemical bonds.

Answer 5

breaking; formation

Question 6

Molecules must _____ energy to break their bonds and _____ energy when their bonds are reformed.

Answer 6

absorb; liberate

Question 7

Excess heat energy liberated by an oxidation reaction is called the _____ .

Answer 7

heat of combustion

Question 8

True or False: All reactions require an energy input to start them.

Answer 8

ture

Question 9

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

Answer 9

ignition

Question 10

A fuel achieves a sufficient reaction rate with oxygen to produce a flame only in the _____ state.

Answer 10

gaseous

Question 11

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

Answer 11

flash point

Question 12

_____ is the chemical breakdown of a solid material to gaseous products.

Answer 12

pyrolysis

Question 13

The _____ defines the upper and lower limits between which a mixture of gaseous fuel and air burns.

Answer 13

flammable range

Question 14

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

Answer 14

glowing combustion

Question 15

True or False: The rate of a chemical reaction increases as the temperature rises.

Answer 15

True

Question 16

_____ describes a fire caused by a natural heat-producing process in a poorly ventilated area.

Answer 16

spontaneous combustion

Question 17

True or False: An immediate search of a fire scene can commence without obtaining a search warrant.

Answer 17

True

Question 18

A search of the fire scene must focus on finding the fire’s _____ .

Answer 18

origin

Question 19

True or False: The origin of a fire is most likely to be located closest to the lowest point that shows the most intense characteristics of burning.

Answer 19

True

Question 20

A portable _____ detector can suck in the air surrounding a questioned sample to rapidly screen for the presence of volatile residues at fire scenes.

Answer 20

vapor

Question 21

True or False: The collection of debris at the origin of a fire should include all nonporous materials.

Answer 21

False

Question 22

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

Answer 22

airtight

Question 23

True or False: Substrate controls should be collected at a fire scene from an area where it can be reasonably assumed that no flammable substance was placed.

Answer 23

True

Question 24

A(n) _____ is a mechanism consisting of a glass bottle containing flammable liquid with a cloth rag stuffed into it and lit as a fuse.

Answer 24

Molotov cocktail

Question 25

The simplest way to recover accelerant residues from fire-scene debris for identification is to heat the airtight container in which the sample is packaged and remove the _____ with a syringe.

Answer 25

headspace

Question 26

The most sensitive and reliable instrument for detecting and characterizing flammable residues is the _____ .

Answer 26

gas chromatography

Question 27

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

Answer 27

mass spectrometer

Question 28

Rapid combustion accompanied by the creation of large volumes of gases describes a(n) _____ .

Answer 28

explosion

Question 29

True or False: Chemicals that supply oxygen are known as oxidizing agents.

Answer 29

True

Question 30

Explosives that decompose at relatively slow rates are classified as _____ explosives.

Answer 30

low

Question 31

The speed at which low explosives decompose is called the speed of _____ .

Answer 31

deflagration

Question 32

Three ingredients of black powder are _____ , _____ , and _____ .

Answer 32

potassium nitrate; charcoal; sulfur

Question 33

_____ explosives detonate almost instantaneously to produce a smashing or shattering effect.

Answer 33

high

Question 34

The most widely used low explosives are _____ and _____ .

Answer 34

black powder; smokeless powder

Question 35

A low explosive becomes explosive and lethal only when it is _____ .

Answer 35

confined

Question 36

True or False: Air and a gaseous fuel burn when mixed in any proportions.

Answer 36

False

Question 37

High explosives can be classified as either _____ or _____ explosives.

Answer 37

primary; secondary

Question 38

The most widely used explosive in the military is _____ .

Answer 38

RDX

Question 39

The explosive core in detonating cord is _____ .

Answer 39

PETN

Question 40

A high explosive is normally detonated by a(n) _____ explosive contained within a blasting cap.

Answer 40

initiating

Question 41

An obvious characteristic of a high explosive is the presence of a(n) _____ at the origin of the blast.

Answer 41

crater

Question 42

To screen objects for the presence of explosive residues in the field or the laboratory, the investigator may use a handheld _____ .

Answer 42

ion mobility spectrometer

Question 43

Unconsumed explosive residues may be detected in the laboratory through a careful examination of the debris.

Answer 43

microscopic

Question 44

True or False: Debris and articles at an explosion scene that are collected from different areas are to be packaged in separate airtight containers.

Answer 44

True

Question 45

Which substance has the highest ignition temperature?

Answer 45

Benzene

Question 46

The rapid combination of oxygen with a fuel that results in a noticeable release of energy is called what?

Answer 46

Combustion

Question 47

The minimum temperature at which a liquid fuel will produce enough vapor to burn is called the what?

Answer 47

Flash point

Question 48

Which instrumentation is considered the most sensitive and reliable for detecting and characterizing flammable residues?

Answer 48

GC

Question 49

What is the decomposition of organic matter by heat called?

Answer 49

Pyrolysis

Question 50

Which chemical reaction is associated with a fire?

Answer 50

Oxidation

Question 51

Which of the following cannot be determined from a laboratory examination of evidence recovered from an arson?

Answer 51

The brand name of gasoline used to start the fire.

Question 52

Which of the following can be determined from a laboratory examination of evidence recovered from an arson?

Answer 52

The presence of accelerate agent in debris The ignition mechanism (used by arsonist) Origin of liquid gasolines

Question 53

The heat generated in a chemical reaction comes from what?

Answer 53

Breaking and formation of chemical bonds

Question 54

Combustion that occurs at the surface of a solid is known as what?

Answer 54

Glowing combustion

Question 55

T or F: Primary explosives are stable.

Answer 55

False

Question 56

T or F: Black powder a high explosive

Answer 56

False

Question 57

Most explosives can be recovered from debris for future study by being rinsed with what?

Answer 57

Acetone

Question 58

What's the homemade explosive that has been used by terrorist organizations in the Middle East?

Answer 58

TATP

Question 59

What method is used to screen objects for the presence of explosive residues?

Answer 59

Ion-mobility spectrometry

Question 60

Which of the following explosive materials is available in commercial form as fertilizer?

Answer 60

Ammonium nitrate