Forensic Chemistry

Question 1

Significance

Answer 1

Trace evidence is almost always class evidence. Level of significance accompany class evidence when it is presented in court

Question 2

Fibres

Answer 2

Divided into natural and manmade

Question 3

Glass

Answer 3

Tempered and laminated glass which are commonly found in cars

Question 4

Paint

Answer 4

Large databases exist for car paints

Question 5

Soil

Answer 5

Naturally occurring material

Question 6

Arson

Answer 6

Fire investigators collect evidence. Chemists analyze it in the lab

Question 7

Accelerant

Answer 7

any material used to start or sustain a fire

Question 8

Control sample

Answer 8

A substrate control collected at the scene with any evidence of accelerant

Question 9

Low Explosives

Answer 9

Speed of deflagration. Rapid oxidation producing heat, light, and a low-intensity subsonic pressure wave.
Decomposes slowly to produce a propelling action

Question 10

High Explosives

Answer 10

Speed of detonation. Oxidation is rapid and accompanied with a violent supersonic shock wave. Must be detonated by an initial explosion.

Question 11

Primary explosive

Answer 11

Divided from high explosives. Ultrasensitive to heat shock or friction and will detonate violently and easily

Question 12

Secondary explosive

Answer 12

Divided from high explosives. Relatively insensitive and usually detonated by an initial explosion.

Question 13

Trace evidence analysis

Answer 13

different substances absorb light in different ways

Question 14

Chromatography

Answer 14

Separates components of a mixture of substances and tentatively ID them

Question 15

Gas chromatography

Answer 15

Separates mixtures based on their distribution between a stationary liquid phase and a moving gas phase. Heat is added (pyrolysis) to break the substance down into a gas

Question 16

Thin-layer chromatography

Answer 16

Plate coated in a thin layer of granular stationary phase and a mobile liquid phase and used with temperature sensitive compounds

Question 17

High performance liquid chromatography

Answer 17

Separates compounds using stationary phase and a mobile liquid and used with temperature sensitive compounds

Question 18

Spectrophotometry

Answer 18

Analytical method for identifying a substances by its selective absorption of different wavelengths of light

Question 19

Mass spectrometry

Answer 19

Coupled with GC and separates a mixture’s components. Ionized and identified by characteristic fragmentation patterns of the spectra produced by MS