Explosives (2)
This is a blasting explosive that is based on nitroglycerin (C₃H₅N₃O₉).
Dynamite
Why was dynamite safer to handle than pure nitroglycerin?
It was mixed with kieselguhr, a porous siliceous earth, making it shock-resistant
What is the Greek origin of the word “dynamite”?
Dynamis
What was Alfred Nobel’s key improvement in the formulation of dynamite?
Replacing kieselguhr with active ingredients like wood pulp and sodium nitrate
What major industries benefited from Alfred Nobel’s invention of dynamite?
Mining, construction, and demolition
Which explosive ingredient did Nobel’s dynamite contain in its first formulation?
75% nitroglycerin and 25% diatomaceous earth
What makes the modern dynamite formulation more efficient than the original?
It includes additional ingredients like wood pulp and sodium nitrate for greater strength and varied effects
Dynamite was initially more dangerous to handle than pure nitroglycerin.
False (Dynamite was safer due to its shock-resistant nature)
The main goal of dynamite was to create a powerful explosive for use in warfare.
False (It was intended to revolutionize industries like mining and construction)
Which of the following components is found in straight dynamite?
Nitroglycerine, sodium nitrate, and wood pulp
What is the primary characteristic of ammonia dynamite?
It contains ammonium nitrate
What gives gelatin dynamite its gel-like consistency?
Nitrocellulose
Which type of dynamite has the highest detonation velocity?
Gelatin dynamite
What is the typical detonation velocity of straight dynamite?
Around 4,000 m/s
How is the energy output of dynamite typically measured?
In terms of TNT equivalent
What is the main purpose of the combustible absorbent in straight dynamite?
To stabilize the nitroglycerin and reduce shock sensitivity
The combustible absorbent in straight dynamite helps to stabilize nitroglycerin and make it safer to handle.
True
What was the primary target of the bombing in Saigon in August 1965?
Special police headquarters
How many people were killed in the Saigon bombing incident?
4
What role did forensic science play in investigating the bombing?
It helped piece together critical information to identify perpetrators and motives
True or False | U.S. officials and Vietnamese investigators agreed on who was responsible for the bombing.
False (U.S. officials blamed the Vietcong, while Vietnamese investigators thought it was revenge for Colonel Pham Ngoc Thao’s death)
True or False | The Vietnamese government believed the bombing was a retaliatory act by supporters of Colonel Pham Ngoc Thao.
True
True or False | The use of machine guns by the attackers was a primary reason for the success of their escape.
True
What is the primary function of a blasting cap?
To create a shock wave that ignites a charge of high explosives
When were electric blasting caps first introduced?
In the 1880s
Blasting caps are classified as which type of explosives?
Class A explosives
Which of the following is true about the 18th-century versions of blasting caps?
They used black powder ignited by electric sparks
True or False | The primary function of a blasting cap is to create a shock wave that ignites a high explosive charge.
True
True or False | The earliest blasting caps used electric sparks to ignite black powder.
True
What is the primary function of a fuse cap?
To provide a time delay before detonation
What does a fuse cap contain that allows it to create a time delay?
A metal cylinder filled with explosive mix and fuse
What is the advantage of using electric blasting caps?
They provide more precise control over timing
Which part of an electric blasting cap ignites the explosive?
A bridge wire heated by an electric current
How do match type caps differ from other types of blasting caps?
They incorporate an electric match for safer handling
Which type of blasting cap is commonly used for precise timing in detonations?
Electric blasting caps
In fuse caps, what happens after the fuse burns down?
It ignites the explosive mix
True or False | Electric blasting caps are the most commonly used type of detonator for large-scale explosions.
True
True or False | Match type caps can be assembled and handled separately, increasing risk before detonation.
False
These are metal cylinders filled
with a pyrotechnic fuse and an explosive mix
Fuse Caps
These utilize an electric current to heat a bridge wire that ignites a primary explosive, which then detonates a secondary explosive charge.
Electric Blasting caps
What material is often used for the metal shell of a blasting cap?
Aluminum
Which of the following is commonly used as a primary explosive in blasting caps?
Mercury fulminate
Which of the following is a characteristic of a blasting cap’s metal shell?
Closed at one end to contain the explosion
What is a common injury pattern caused by blasting caps, as seen in cranial trauma analysis?
High-velocity gunshot wounds
True or False | Blasting caps typically have an open-ended metal shell.
False (They are typically closed at one end)
True or False | The metal shell of a blasting cap is made to contain the explosion and protect the surrounding environment.
True
What are the main components of black powder?
Potassium nitrate, sulfur, and aluminum
What is the primary hazard of black powder?
It can detonate instantly when ignited
What is typically used to coat potassium nitrate in black powder to prevent electrostatic charge build-up?
Charcoal
In which of the following applications is black powder commonly used?
All of the above
Which factor affects the burn rate of black powder?
The size of the granules
What is the main role of sulfur in black powder?
To reduce ignition temperature
What happens when black powder is ignited?
It burns very quickly, producing a blast
Which of the following is a characteristic of black powder when it is prepared commercially?
It is coated with graphite to prevent electrostatic charge
Black powder is used in practice bombs for what purpose?
As spatting charges for practice
True or False | Black powder is an intimate mixture of potassium nitrate, sulfur, and charcoal.
True
True or False | Graphite is used to coat potassium nitrate in black powder to prevent electrostatic charge build-up.
True
True or False | The larger the granules in black powder, the faster it burns.
False (Larger granules cause a slower burn rate)
Potassium nitrate is used in black powder because it acts as a fuel source.
False (Potassium nitrate is an oxidizer, not a fuel source)
In commercial black powder, potassium nitrate or another nitrate is usally coated with ______________ to prevent electrostatic charge build-up.
graphite
Which type of black powder is used mainly in cannons or large-caliber firearms?
Fg
What is the primary characteristic of FFg black powder?
It is used in shotguns and larger-caliber rifles
Which type of black powder is most commonly used in .45 caliber and smaller rifles?
FFFg
True or False | Fg black powder is used primarily in smaller-caliber rifles.
False (Fg is used in cannons or large-caliber firearms)
True or False | Charcoal is used instead of pure carbon because it has a higher autoignition temperature.
False (Charcoal has a lower autoignition temperature than pure carbon)
True or False | The oxidizer in black powder is sulfur, which helps to increase the combustion rate
False (The oxidizer in black powder is potassium nitrate, while sulfur helps to lower the ignition temperature)
This powder is used for priming flintlock muzzleloaders. The finer the granulation of powder, the more pressure it creates when fired.
FFFFg
Very coarse granules of powder used mainly in cannons or large caliber firearms.
Fg
True or False | Charcoal and sulfur act as the fuel for the explosion, while saltpeter acts as an oxidizer.
True
What is the chemical name of Picric Acid?
2,4,6-Trinitrophenol (TNP)
Picric acid is highly sensitive to which of the following?
Shock, heat, and friction
Only sunlight
138–140 °C
How can Picric Acid be identified in residue analysis?
Yellow crystalline or powdery residue
What is the detonation point of Picric Acid?
210 °C
True or False | Picric Acid is a highly stable explosive, especially when dry.
False (Picric Acid is unstable, especially when dry)
True or False | Picric Acid can be identified through colorimetric reactions or spectroscopic analysis.
True
True or False | Picric Acid is a low explosive material, suitable for everyday use.
False (Picric Acid is a high explosive)
What is the chemical formula of Picric Acid?
C₆H₃(NO₃)₃OH
True or False | Picric Acid turns brownish over time.
True
What is a primary byproduct of Picric Acid degradation?
Nitrophenols
Which of the following gases are released when Picric Acid decomposes?
Nitrogen Oxides
What type of salts can form when Picric Acid interacts with metals?
picrate salts
Which of the following is NOT a breakdown product of Picric Acid?
Sodium hydroxide
What is the primary chemical component of Nitrocellulose?
Cellulose
What is the effect of high nitrogen content on Nitrocellulose?
It becomes a high-order explosive
What is the characteristic appearance of Nitrocellulose when dry?
A fluffy white solid
What solvent can Nitrocellulose dissolve in to form a clear liquid or semisolid?
Acetone or alcohol
What is the critical temperature range at which Nitrocellulose can ignite?
160–170°C
Which of the following is used in the preparation of Nitrocellulose?
Nitric acid and sulfuric acid
How is Nitrocellulose categorized based on its nitrogen content?
High explosive when nitrogen content exceeds 12.6%
What makes Nitrocellulose highly volatile?
Its solubility in organic solvents like acetone
What form of Nitrocellulose is typically used in photographic films?
Mononitrocellulose
What is the chemical test used to detect Nitrocellulose?
Diphenylamine test
True or False | Nitrocellulose is highly flammable and can be ignited by heat, friction, or static electricity.
True
True or False | Nitrocellulose’s density increases with higher nitrogen content.
False
True or False | The primary component of Nitrocellulose is cellulose, a polysaccharide made up of glucose units.
True
True or False | Nitrocellulose has low volatility and is considered safe to handle under normal conditions.
False
Which of the following is a sign of Nitrocellulose decomposition?
Turns yellow or brown
What type of odor does decomposing Nitrocellulose emit?
Sharp, acidic odor similar to nitric acid
What physical change can occur in Nitrocellulose when it decomposes?
Becomes sticky or exudes moisture
Which environmental condition can accelerate Nitrocellulose decomposition?
Poor ventilation or humidity
Which of the following is NOT a by-product of Nitrocellulose decomposition?
Oxygen
What is a positive indicator of Nitrocellulose decomposition during analysis?
Fibrous or polymeric residue
What is the primary use of PETN?
In detonators and blasting caps
What type of chemical compound is PETN?
Nitrate ester
What is the main base molecule of PETN?
Pentaerythritol
How many nitrate groups are attached to the pentaerythritol molecule in PETN?
Four
What is the melting point of PETN?
141.3°C
What is the physical appearance of PETN?
White crystalline solid
Why is PETN considered a brisant explosive?
It detonates with extreme violence
Which of the following is NOT a sign of PETN instability?
Increased transparency
What chemical should be checked for when investigating the breakdown of PETN?
Nitrous acid (HNO2)
What physical changes may indicate PETN decomposition?
Formation of lumps or cracks
True or False | PETN should be checked for the presence of nitrous acid when it starts to decompose.
True