Pentaerythritol tetranitrate MCQs With Answer

Pentaerythritol tetranitrate MCQs With Answer is a focused review resource for B. Pharm students covering the chemistry, pharmacology, toxicology, safety, and analytical detection of PETN. This introduction highlights PETN as a tetranitrate ester (PETN), an energetic organic nitrate with dual importance in explosive chemistry and nitrate pharmacology. Key concepts include chemical structure and formula, nitration synthesis, nitrate-ester reactivity, nitric oxide–mediated vasodilation, tolerance mechanisms, stability and handling, environmental fate, and modern detection methods (GC-MS, IR, ion chromatography). The questions that follow are designed to deepen conceptual understanding and prepare students for applied pharmaceutical and safety contexts. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. Which functional group characterizes pentaerythritol tetranitrate (PETN)?

• Nitrate ester
• Carbamate
• Nitroaromatic
• Sulfate ester

Correct Answer: Nitrate ester

Q2. What is the molecular formula of PETN?

• C5H8N4O12
• C5H10N4O8
• C4H6N2O6
• C6H6N6O9

Correct Answer: C5H8N4O12

Q3. Which reagent combination is conventionally used to synthesize PETN from pentaerythritol?

• Concentrated nitric acid and concentrated sulfuric acid (nitration mixture)
• Hydrogen peroxide and acetic acid
• Thionyl chloride and pyridine
• Sodium nitrite in water

Correct Answer: Concentrated nitric acid and concentrated sulfuric acid (nitration mixture)

Q4. PETN belongs primarily to which class of energetic materials?

• Nitrate esters
• Nitramines
• Nitroaromatics
• Peroxides

Correct Answer: Nitrate esters

Q5. Which property most closely explains why PETN is used as a high explosive?

• High oxygen content and rapid decomposition to gaseous products
• High solubility in water
• Strong basicity
• Low vapor pressure

Correct Answer: High oxygen content and rapid decomposition to gaseous products

Q6. Which analytical technique is commonly employed to identify PETN residues in forensic samples?

• Gas chromatography–mass spectrometry (GC–MS)
• Polarimetry
• UV–visible spectrophotometry without derivatization
• Paper chromatography with iodine staining

Correct Answer: Gas chromatography–mass spectrometry (GC–MS)

Q7. In pharmaceutical/toxicological context, organic nitrates like PETN exert vasodilatory effects primarily by releasing which mediator?

• Nitric oxide (NO)
• Acetylcholine
• Histamine
• Bradykinin

Correct Answer: Nitric oxide (NO)

Q8. Which enzyme has been implicated in the bioactivation of some organic nitrates to produce NO?

• Mitochondrial aldehyde dehydrogenase (ALDH2)
• Cytochrome P450 reductase
• Monoamine oxidase (MAO)
• Acetylcholinesterase

Correct Answer: Mitochondrial aldehyde dehydrogenase (ALDH2)

Q9. Which safety consideration is most important when handling PETN in a laboratory?

• Avoid friction, shock, and heat due to sensitivity to initiation
• Always store PETN under strong base
• Ensure long exposure to sunlight for stabilization
• Keep PETN immersed in water during handling

Correct Answer: Avoid friction, shock, and heat due to sensitivity to initiation

Q10. Regarding environmental fate, which transformation is likely for PETN released into water or soil over time?

• Hydrolysis and microbial degradation to pentaerythritol and nitrate ions
• Polymerization to form insoluble macromolecules
• Rapid volatilization to air unchanged
• Spontaneous aromatization to nitrobenzene

Correct Answer: Hydrolysis and microbial degradation to pentaerythritol and nitrate ions

Q11. Which physical property is characteristic of PETN in its pure crystalline form?

• High density and crystalline solid appearance
• Low density oily liquid
• Gaseous at room temperature
• Highly hygroscopic powder that dissolves in water

Correct Answer: High density and crystalline solid appearance

Q12. Which statement about nitrate tolerance is correct and relevant to organic nitrates?

• Repeated exposure to organic nitrates can lead to decreased responsiveness (tolerance)
• Nitrate tolerance results in permanent receptor loss that cannot reverse
• Tolerance only occurs with topical application, not with systemic use
• Nitrate tolerance is due to accumulation of unmetabolized nitrate esters in tissues

Correct Answer: Repeated exposure to organic nitrates can lead to decreased responsiveness (tolerance)

Q13. Which solvent property makes PETN difficult to work with in routine aqueous pharmaceutical assays?

• Very low solubility in water
• High miscibility with water
• Strong acidic character
• High volatility

Correct Answer: Very low solubility in water

Q14. Which class of reagents is typically used to detect nitrate ester functional groups by infrared spectroscopy?

• No reagent required; characteristic IR absorptions (NO stretching) identify esters
• Chromic acid oxidation
• Schiff’s reagent
• Benedict’s reagent

Correct Answer: No reagent required; characteristic IR absorptions (NO stretching) identify esters

Q15. PETN decomposition during detonation primarily produces which of the following?

• Large volumes of hot gaseous products (CO2, N2, H2O) and shock wave energy
• Stable solid polymer and minimal gas
• Pure oxygen and hydrogen gas
• Inert carbon black only

Correct Answer: Large volumes of hot gaseous products (CO2, N2, H2O) and shock wave energy

Q16. For forensic extraction of PETN from soil, which analytical approach is most appropriate?

• Solvent extraction followed by LC-MS or GC-MS analysis
• Titration with standard acid
• Direct UV measurement of unextracted soil
• Thin-layer chromatography without extraction

Correct Answer: Solvent extraction followed by LC-MS or GC-MS analysis

Q17. Which regulatory concern is directly associated with PETN from a pharmaceutical perspective?

• Control as an explosive and strict transport and storage regulations
• Requirement to label as a controlled antibiotic
• Mandatory inclusion in all sterile injectables
• Registration as a food additive

Correct Answer: Control as an explosive and strict transport and storage regulations

Q18. Which adverse clinical effect is commonly associated with nitrate exposure in humans?

• Headache and hypotension
• Hyperglycemia
• Severe constipation
• Hypothyroidism

Correct Answer: Headache and hypotension

Q19. Which statement best describes PETN’s sensitivity compared to other energetic materials?

• Relatively sensitive to shock and friction compared with many secondary explosives
• Completely insensitive and safe to drop or strike
• More sensitive than primary explosives like lead azide in all conditions
• Only decomposes when exposed to direct sunlight

Correct Answer: Relatively sensitive to shock and friction compared with many secondary explosives

Q20. Which detoxification pathway is relevant for nitrate esters in biological systems?

• Reductive denitration and enzymatic metabolism to release NO and alcohol derivatives
• Direct conjugation with glucuronic acid without prior metabolism
• Oxidative polymerization to inert oligomers
• Complete excretion unchanged in urine

Correct Answer: Reductive denitration and enzymatic metabolism to release NO and alcohol derivatives

Q21. In quality control of explosives, which physical test can indicate PETN crystallinity and purity?

• Melting point determination
• pH titration
• Fate mapping chromatography
• Organoleptic tasting

Correct Answer: Melting point determination

Q22. What risk does improper storage of PETN pose in a pharmaceutical laboratory?

• Spontaneous initiation leading to detonation under adverse conditions
• Conversion to therapeutic nitrate compounds
• Loss of pharmacological potency as a vasodilator
• Increased solubility making it easy to clean

Correct Answer: Spontaneous initiation leading to detonation under adverse conditions

Q23. Which statement about PETN’s use as a pharmaceutical agent is most accurate?

• While PETN is principally an explosive, nitrate esters in general are pharmacologically active as vasodilators
• PETN is widely used as a first-line oral antihypertensive in clinical practice
• PETN is routinely added to over-the-counter analgesics for pain relief
• PETN has no biological activity and is inert in humans

Correct Answer: While PETN is principally an explosive, nitrate esters in general are pharmacologically active as vasodilators

Q24. Which lab precaution reduces the chance of accidental PETN initiation during analysis?

• Use minimal mechanical agitation and avoid grinding or impact
• Heat samples aggressively to speed analysis
• Mix PETN with finely divided metal powders to stabilize
• Store samples in direct sunlight to dry them thoroughly

Correct Answer: Use minimal mechanical agitation and avoid grinding or impact

Q25. Which ion chromatography target is useful for monitoring PETN degradation in environmental samples?

• Nitrate ions (NO3–)
• Chloride ions (Cl–)
• Phosphate ions (PO4^3–)
• Sulfate ions (SO4^2–)

Correct Answer: Nitrate ions (NO3–)

Q26. Which spectroscopic feature is characteristic of nitrate esters like PETN in IR spectra?

• Strong absorptions in the NO stretching region (~1200–1600 cm⁻¹)
• Sharp OH stretching peak at 3500 cm⁻¹ only
• Intense C–H stretch at 3000 cm⁻¹ unique to nitrate esters
• Absence of any strong peaks in fingerprint region

Correct Answer: Strong absorptions in the NO stretching region (~1200–1600 cm⁻¹)

Q27. Which formulation application commonly uses PETN in energetic devices (non-pharmaceutical)?

• Detonating cord and booster charges
• Oral tablets for angina relief
• Topical antiseptic creams
• Parenteral antibiotics

Correct Answer: Detonating cord and booster charges

Q28. When analyzing trace PETN on surfaces, which sample collection method is typically used?

• Wipe sampling with suitable solvent extraction
• Tongue swabbing for taste detection
• Thermal desorption without preconcentration
• Direct incineration of the surface

Correct Answer: Wipe sampling with suitable solvent extraction

Q29. In toxicology, which acute effect is a concern after ingestion or exposure to nitrate esters?

• Severe hypotension and potential methemoglobinemia in high exposures
• Acute hyperglycemia and insulin resistance
• Permanent renal calcification within minutes
• Immediate permanent blindness in all cases

Correct Answer: Severe hypotension and potential methemoglobinemia in high exposures

Q30. Which factor is most important when deciding appropriate decontamination for PETN spills in a lab?

• Quantity, form (crystalline vs. solution), and potential for mechanical initiation
• Whether PETN tastes sweet or bitter
• Whether PETN fluoresces under UV light
• Color of the laboratory bench surface

Correct Answer: Quantity, form (crystalline vs. solution), and potential for mechanical initiation

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com