FSC311 Forensic
Chemistry Exam Review
& Comprehensive Study
Guide
| Guaranteed success|
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,Examples of Physical Evidence - Blood/Semen/Saliva: Liquid or dried that may suggest a relation to the
offence, detection of possible existence of drugs or poisons.
- Drugs: Any substances seized in violation of laws regulating the sale,
manufacturer, distribution and use of drugs.
- Firearms/ammunition: Evidence involved in criminal offence.
- Explosives: Device containing explosive discharge.
- Glass: Transfer of glass particle/fragment from person/object.
- Paint: Transfer, liquid or dried, from one surface of an object to another
during commission of a crime.
- Toolmarks: Impression made by a tool in a crime.
- Hair and fibre: May assist in establishing transfers between individuals or
objects.
Analysis of Physical Evidence 1. Identification.
2. Comparison (Q vs. K).
Identification - Determination of physical and chemical identification of a substance with
near absolute certainty as analytical technique will permit.
- Degree of certainty will depend on degree of sensitivity and specificity of
the analytical technique.
Comparison - Q vs. K; process of ascertaining whether two or more objects have a common
origin.
- Specimen vs. standard/reference sample.
Properties of Matter 1. Matter.
2. Physical Property.
3. Chemical Property.
Matter - Anything made up of atoms and molecules.
- Takes up space and has a mass
Physical Property Describes the characteristic (state) of a substance without any change in
composition (Ex. mass, density, colour, volume, BP, MP).
Chemical Property Describes the characteristic of a substance when it undergoes a change in
composition; one or more kinds of matter combine to form a new matter with a
different composition (Ex. flammability, chemical reactions).
Chemical Spot Tests - Screening tool used to tentatively identify a drug/drug class/poisons.
- Many drugs yield characteristic colours when reacted with specific chemical
reagents.
Chemical Spot Tests - Cause of Colour Change 1. Production of a highly conjugated system (Ex. Marquis reagent).
2. Formation of transition metal complexes (Ex. cobalt thiocyanate).
,Marquis Test - Presumptive test for the presence of alkaloids, such as heroin, morphine,
amphetamine and most of their derivatives.
- When marquis reagent is used with alkaloids, it creates many colours because
they are conjugated differently.
- Production of a highly conjugated system.
- Several expectant colour products that may be observed indicating a positive
result, as these drugs conjugate differently. However, when the marquis
reagent is reacted with morphine a purple colour is expected and when it is
reacted with amphetamines an orange colour is expected.
Scott Test - Cobalt thiocyanate.
- Tests for the presence of cocaine.
- Produces transition metal complex.
- Positive result = Blue.
Duquenois-Levine Test - Tests for marijuana.
- It reacts with cannabinoids to produce a highly conjugated system (adjacent
double bonds).
- Positive result = Purple.
Mandelin Test - Tests for basic drugs, primarily ketamine and PMA.
- It reacts primarily with alkaloids to produce transition metal complexes.
- Several colours = Some include reddish/brown (PMA) or reddish/orange
(ketamine).
Ferric Chloride - Tests for salicylates.
- It reacts with phenolic compounds.
- Positive result = Blue, violet, purple, red-brown, or green.
Zwikker Test - Tests primarily for barbiturates and CNS depressants.
- Positive result = Purple or yellow/green.
Energy and Wavelength Equation - Electromagnetic energy interacts with matter.
- The lower the wavelength, the higher the energy.
Visible Light - 400 nm - 700 nm.
- Energy trend: Red (low energy) < Orange < Yellow < Green < Blue < Violet
(high energy).
Conjugated System Alternating double bonds, single bond, double bond.
, When does a compound absorb light? - More complex molecules, having several multiple
- Complex absorbs light when it is a conjugated system.
- Degree of conjugation affects the colour of the compound.
UV/Vis - When light/energy is absorbed by a molecule valence (outer shell) electrons
are excited from a lower energy state to an excited (△o).
- Degree of conjugation determines the magnitude of excitation (△o).
- The higher degree of conjugation the less energy is required to excite.
- E.g.: Chlorophyll (highly conjugated system) in plant absorb red (low energy),
and reflect green (higher energy) --> Huge electron cloud --> Only needs a
small amount of energy to get excited.
Transition Metals An element whose atom has a partially filled d sub-shell, or which can give rise
to cations with an incomplete d sub-shell.
When transition metal coordinate (bonded to) with d orbital splitting
ligands __________________ occurs because certain
geometrical arrangements are more favourable than
others.
Why are organic compounds important? Forensic chemists need to be able to categorize compounds into organic and
inorganic --> Once they are able to do so, they can determine the type of tools
that are at their disposal in the analysis of forensic evidence.
Compound - A substance formed from two or more elements.
- Can be subdivided into organic and inorganic.
Organic Compounds - Compounds composed of carbon and hydrogen and usually other elements
such as oxygen, nitrogen, chlorine, phosphorus, or other elements.
- Exceptions: Carbonates, cyanides, carbides (because they lack C-C bonds).
Spectroscopy - Science that deals with the interaction of various types of radiation with
matter --> When we bombard energy or electromagnetic radiation at it we can
get some information about the compound, like it physical or chemical
characteristics.
- Use light (IR, UV-vis, X-ray) to interrogate physical evidence and retrieve
information (qualitative & quantitative).
- Most familiar with the visible range of the electromagnetic spectrum (red
square) --> 400nm (blue) to 700nm (red).
Electromagnetic radiation such as visible light is a wave
commonly treated as...
Chemistry Exam Review
& Comprehensive Study
Guide
| Guaranteed success|
Updated 2026 Questions and Answers
100% Verified Exam Prep and Comprehensive
Rationales
Included
,Examples of Physical Evidence - Blood/Semen/Saliva: Liquid or dried that may suggest a relation to the
offence, detection of possible existence of drugs or poisons.
- Drugs: Any substances seized in violation of laws regulating the sale,
manufacturer, distribution and use of drugs.
- Firearms/ammunition: Evidence involved in criminal offence.
- Explosives: Device containing explosive discharge.
- Glass: Transfer of glass particle/fragment from person/object.
- Paint: Transfer, liquid or dried, from one surface of an object to another
during commission of a crime.
- Toolmarks: Impression made by a tool in a crime.
- Hair and fibre: May assist in establishing transfers between individuals or
objects.
Analysis of Physical Evidence 1. Identification.
2. Comparison (Q vs. K).
Identification - Determination of physical and chemical identification of a substance with
near absolute certainty as analytical technique will permit.
- Degree of certainty will depend on degree of sensitivity and specificity of
the analytical technique.
Comparison - Q vs. K; process of ascertaining whether two or more objects have a common
origin.
- Specimen vs. standard/reference sample.
Properties of Matter 1. Matter.
2. Physical Property.
3. Chemical Property.
Matter - Anything made up of atoms and molecules.
- Takes up space and has a mass
Physical Property Describes the characteristic (state) of a substance without any change in
composition (Ex. mass, density, colour, volume, BP, MP).
Chemical Property Describes the characteristic of a substance when it undergoes a change in
composition; one or more kinds of matter combine to form a new matter with a
different composition (Ex. flammability, chemical reactions).
Chemical Spot Tests - Screening tool used to tentatively identify a drug/drug class/poisons.
- Many drugs yield characteristic colours when reacted with specific chemical
reagents.
Chemical Spot Tests - Cause of Colour Change 1. Production of a highly conjugated system (Ex. Marquis reagent).
2. Formation of transition metal complexes (Ex. cobalt thiocyanate).
,Marquis Test - Presumptive test for the presence of alkaloids, such as heroin, morphine,
amphetamine and most of their derivatives.
- When marquis reagent is used with alkaloids, it creates many colours because
they are conjugated differently.
- Production of a highly conjugated system.
- Several expectant colour products that may be observed indicating a positive
result, as these drugs conjugate differently. However, when the marquis
reagent is reacted with morphine a purple colour is expected and when it is
reacted with amphetamines an orange colour is expected.
Scott Test - Cobalt thiocyanate.
- Tests for the presence of cocaine.
- Produces transition metal complex.
- Positive result = Blue.
Duquenois-Levine Test - Tests for marijuana.
- It reacts with cannabinoids to produce a highly conjugated system (adjacent
double bonds).
- Positive result = Purple.
Mandelin Test - Tests for basic drugs, primarily ketamine and PMA.
- It reacts primarily with alkaloids to produce transition metal complexes.
- Several colours = Some include reddish/brown (PMA) or reddish/orange
(ketamine).
Ferric Chloride - Tests for salicylates.
- It reacts with phenolic compounds.
- Positive result = Blue, violet, purple, red-brown, or green.
Zwikker Test - Tests primarily for barbiturates and CNS depressants.
- Positive result = Purple or yellow/green.
Energy and Wavelength Equation - Electromagnetic energy interacts with matter.
- The lower the wavelength, the higher the energy.
Visible Light - 400 nm - 700 nm.
- Energy trend: Red (low energy) < Orange < Yellow < Green < Blue < Violet
(high energy).
Conjugated System Alternating double bonds, single bond, double bond.
, When does a compound absorb light? - More complex molecules, having several multiple
- Complex absorbs light when it is a conjugated system.
- Degree of conjugation affects the colour of the compound.
UV/Vis - When light/energy is absorbed by a molecule valence (outer shell) electrons
are excited from a lower energy state to an excited (△o).
- Degree of conjugation determines the magnitude of excitation (△o).
- The higher degree of conjugation the less energy is required to excite.
- E.g.: Chlorophyll (highly conjugated system) in plant absorb red (low energy),
and reflect green (higher energy) --> Huge electron cloud --> Only needs a
small amount of energy to get excited.
Transition Metals An element whose atom has a partially filled d sub-shell, or which can give rise
to cations with an incomplete d sub-shell.
When transition metal coordinate (bonded to) with d orbital splitting
ligands __________________ occurs because certain
geometrical arrangements are more favourable than
others.
Why are organic compounds important? Forensic chemists need to be able to categorize compounds into organic and
inorganic --> Once they are able to do so, they can determine the type of tools
that are at their disposal in the analysis of forensic evidence.
Compound - A substance formed from two or more elements.
- Can be subdivided into organic and inorganic.
Organic Compounds - Compounds composed of carbon and hydrogen and usually other elements
such as oxygen, nitrogen, chlorine, phosphorus, or other elements.
- Exceptions: Carbonates, cyanides, carbides (because they lack C-C bonds).
Spectroscopy - Science that deals with the interaction of various types of radiation with
matter --> When we bombard energy or electromagnetic radiation at it we can
get some information about the compound, like it physical or chemical
characteristics.
- Use light (IR, UV-vis, X-ray) to interrogate physical evidence and retrieve
information (qualitative & quantitative).
- Most familiar with the visible range of the electromagnetic spectrum (red
square) --> 400nm (blue) to 700nm (red).
Electromagnetic radiation such as visible light is a wave
commonly treated as...
