Chapter 11

Question 1

A solid, liquid, or gas used to start and sustain an intentionally set fire

Answer 1

Accelerant

Question 2

A combustion in which Q (heat evolved) is used only to heat the reaction products. It is the basis of some simple combustion models

Answer 2

Adiabatic combustion

Question 3

A flame in which the hot gas products and heated air drift up and away from the reaction zone due to density differences generated by heating

Answer 3

Buoyant flame

Question 4

Another term for thermal distillation; applied to refining crude oil. Also incorporates degradation, or catalytic splitting of large molecules into smaller ones

Answer 4

Cracking

Question 5

Burning or combustion that propagates at less than the speed of sound

Answer 5

Deflagration

Question 6

Explosive combustion driven by pressure and a compressive shockwave

Answer 6

Detonation

Question 7

The ratio of a fuel to air relative to a combustion reaction; typically expressed as a weight or volume percent comparison

Answer 7

Fuel/air ratio (F/A)

Question 8

In arson fires, the device used to supply ignition energy

Answer 8

Incendiary device

Question 9

A flame with defined regions delineated by temperatures and flame color

Answer 9

Laminar flame

Question 10

A combustive mixture in which the concentration of oxidant is greater than the stoichiometric ratio

Answer 10

Lean mixture

Question 11

The lowest mixture ratio of fuel and oxidant that will ignite and sustain combustion

Answer 11

Lower flammability limit (LFL)

Question 12

The process of a solute moving in and out of a stationary phase

Answer 12

Mass transfer

Question 13

Samples of pristine background material that must be analyzed to facilitate interpretation of analysis

Answer 13

Matrix controls

Question 14

A measure of the amount of oxygen in a molecule that undergoes combustion. A positive oxygen balance means that all the oxygen needed for complete combustion is available intramolecularly

Answer 14

Oxygen balance

Question 15

A product that is or was at one time derived from crude oil by distillation techniques

Answer 15

Petroleum distillate

Question 16

The location(s) where a fire began

Answer 16

Points of origin

Question 17

A powdered combustive fuel used in firearms; typically contains nitroglycerin and guncotton

Answer 17

Propellants

Question 18

A high temperature decomposition that occurs in a reducing environment; an inlet for instrumentation and also an element of combustion reactions. Often combined with gas chromatography in forensic applications

Answer 18

Pyrolysis (combustion reactions)

Question 19

A combustive mixture in which the concentration of fuel is greater than the stoichiometric ratio

Answer 19

Rich mixture

Question 20

An older name for KNO3, potassium nitrate

Answer 20

Saltpeter

Question 21

The point at which fuel and oxidant create a zero oxygen balance

Answer 21

Stoichiometric equivalence (STE)

Question 22

The highest mixture ratio of fuel and oxidant that will ignite and sustain combustion

Answer 22

Upper flammability limit (UFL)

Question 23

The loss of lighter components of hydrocarbon mixtures used as accelerants

Answer 23

Weathering