Antimicrobials: Potassium permanganate MCQs With Answer

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Antimicrobials: Potassium permanganate MCQs With Answer

Potassium permanganate (KMnO4) is a widely used oxidizing antiseptic in pharmacy and dermatology, valued for its broad-spectrum antimicrobial and astringent effects. B. Pharm students must understand its chemical properties, mechanism of action, safe concentrations for topical use, preparation of dilute solutions, incompatibilities with organic matter, and clinical indications such as eczema, fungal infections, and wound care. This concise, keyword-rich introduction emphasizes practical knowledge on pharmacology, toxicology, handling, and formulation aspects of KMnO4 to enhance exam readiness. Clear understanding aids safe dispensing and patient counseling. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the chemical formula of potassium permanganate commonly used as an antimicrobial?

  • KMnO4
  • K2MnO4
  • MnO2
  • KMnO3

Correct Answer: KMnO4

Q2. Which property primarily explains the antimicrobial action of potassium permanganate?

  • Reduction of microbial enzymes
  • Chelation of metal ions
  • Oxidation of cellular components
  • pH neutralization

Correct Answer: Oxidation of cellular components

Q3. What color are concentrated potassium permanganate crystals?

  • White
  • Deep purple
  • Green
  • Yellow

Correct Answer: Deep purple

Q4. In aqueous solution, potassium permanganate typically appears as which color?

  • Pale blue
  • Pink to purple
  • Clear
  • Orange

Correct Answer: Pink to purple

Q5. Which of the following best describes the spectrum of antimicrobial activity of KMnO4?

  • Only Gram-positive bacteria
  • Only viruses
  • Broad-spectrum against bacteria and fungi
  • Only protozoa

Correct Answer: Broad-spectrum against bacteria and fungi

Q6. Potassium permanganate is contraindicated for use in which situation due to risk of tissue damage?

  • Dilute soak for interdigital lesions
  • Application on extensive deep burns
  • Topical use for fungal infections
  • Soak for vesicular eczema

Correct Answer: Application on extensive deep burns

Q7. Which reaction is a major safety concern when KMnO4 contacts organic materials like glycerin?

  • Endothermic dissolution
  • Explosive oxidation producing heat and flame
  • Formation of inert salts
  • Precipitation of manganese metal

Correct Answer: Explosive oxidation producing heat and flame

Q8. Which brown stain commonly appears after KMnO4 contact with skin due to reduction products?

  • Iron oxide stain
  • Manganese dioxide deposition
  • Lead sulfide stain
  • Copper oxide stain

Correct Answer: Manganese dioxide deposition

Q9. What is a commonly recommended topical concentration range for potassium permanganate soaks in dermatology?

  • 0.001% to 0.005%
  • 0.01% to 0.1%
  • 1% to 5%
  • 10% to 20%

Correct Answer: 0.01% to 0.1%

Q10. What is the primary reason KMnO4 solutions should be freshly prepared and filtered for clinical use?

  • To increase acidity
  • To remove undissolved crystals and organic contaminants
  • To add buffering salts
  • To concentrate the solution

Correct Answer: To remove undissolved crystals and organic contaminants

Q11. Which of the following is a pharmaceutical consideration when storing potassium permanganate crystals?

  • Store with strong reducing agents
  • Store in a cool, dry place away from organics
  • Keep in open containers exposed to air
  • Store in metal containers that react with KMnO4

Correct Answer: Store in a cool, dry place away from organics

Q12. Incompatibility of KMnO4 with which class of substances is most important for compounding safety?

  • Inorganic salts
  • Organic reducing agents and combustibles
  • Neutral buffers
  • Non-ionic surfactants

Correct Answer: Organic reducing agents and combustibles

Q13. Which statement about the solubility of KMnO4 in water is correct?

  • KMnO4 is insoluble in water
  • KMnO4 is moderately to freely soluble in water
  • KMnO4 dissolves only in organic solvents
  • KMnO4 decomposes immediately on dissolving

Correct Answer: KMnO4 is moderately to freely soluble in water

Q14. Which color change indicates reduction of permanganate ion during titrations?

  • Purple to colorless or brown
  • Yellow to green
  • Blue to red
  • Clear to cloudy white

Correct Answer: Purple to colorless or brown

Q15. Which laboratory assay frequently uses KMnO4 as a primary oxidant?

  • Acid-base titration
  • Permanganometry for reducing agents
  • Gravimetric analysis for sulfates
  • Colorimetric pH testing

Correct Answer: Permanganometry for reducing agents

Q16. Which property makes KMnO4 useful as an astringent in topical therapy?

  • Reducing action on proteins
  • Oxidative protein coagulation and drying
  • Hydrating action on tissues
  • Emollient effects

Correct Answer: Oxidative protein coagulation and drying

Q17. When preparing a dilute KMnO4 topical solution, which precaution is essential?

  • Use metal stirring implements that react with KMnO4
  • Dissolve in warm organic solvent
  • Protect from organic contamination and use glass or plastic implements
  • Store final solution in a metal canister

Correct Answer: Protect from organic contamination and use glass or plastic implements

Q18. Which of the following is a common clinical indication for potassium permanganate soaks?

  • Systemic bacterial infection
  • Severe ischemic limb
  • Dermatitis with exudation and secondary infection
  • Deep puncture wound closure

Correct Answer: Dermatitis with exudation and secondary infection

Q19. Which ionic species is the active oxidizing moiety in potassium permanganate solutions?

  • Mn2+
  • MnO4- (permanganate ion)
  • MnO2
  • KMnO3

Correct Answer: MnO4- (permanganate ion)

Q20. Incompatibility may cause deactivation of KMnO4 when it encounters what in wound exudate?

  • Inorganic salts only
  • High levels of organic material and reducing substances
  • Neutral pH fluids
  • Sterile saline without organics

Correct Answer: High levels of organic material and reducing substances

Q21. Which adverse effect is most likely with excessive topical concentration of KMnO4?

  • Systemic hypertension
  • Local chemical burns and irritation
  • Hypoglycemia
  • Renal failure from absorption

Correct Answer: Local chemical burns and irritation

Q22. Which end product commonly forms when KMnO4 oxidizes organic matter?

  • Manganese dioxide (MnO2) and CO2
  • Manganese metal
  • Permanganic acid only
  • Chloride salts

Correct Answer: Manganese dioxide (MnO2) and CO2

Q23. For pharmacy handling, KMnO4 tablets or crystals should be dispensed with which patient advice?

  • Mix with alcoholic solutions for better effect
  • Keep away from clothes and organic materials to avoid staining and reactions
  • Store with reducing agents to enhance potency
  • Ingest small amounts for throat infections

Correct Answer: Keep away from clothes and organic materials to avoid staining and reactions

Q24. Which factor does NOT significantly affect the antimicrobial efficacy of KMnO4 solution?

  • Concentration of KMnO4
  • Presence of organic matter
  • Contact time
  • Color of container

Correct Answer: Color of container

Q25. Which statement best explains why KMnO4 is less effective in heavily soiled wounds?

  • Soil increases pH making KMnO4 inert
  • Organic matter consumes oxidizing capacity, reducing active permanganate
  • Soil converts permanganate to a stronger antiseptic
  • Permanganate binds to proteins enhancing action

Correct Answer: Organic matter consumes oxidizing capacity, reducing active permanganate

Q26. Which test in pharmaceutics uses KMnO4 as an oxidant to estimate organic impurities?

  • Loss on drying
  • Permanganate demand or chemical oxygen demand (COD) type tests
  • Melting point determination
  • pH titration

Correct Answer: Permanganate demand or chemical oxygen demand (COD) type tests

Q27. Which precaution is essential when rinsing the skin after a KMnO4 soak?

  • Rinse with organic solvents
  • Neutralize with strong acids
  • Rinse with clean water to remove residues
  • Apply oil immediately without rinsing

Correct Answer: Rinse with clean water to remove residues

Q28. Which pharmacological classification best fits potassium permanganate when used topically?

  • Topical antibiotic
  • Topical oxidizing antiseptic and astringent
  • Systemic antiviral
  • Emollient

Correct Answer: Topical oxidizing antiseptic and astringent

Q29. What is the visual indication that a KMnO4 solution has been contaminated with excessive organic matter?

  • Solution becomes more purple
  • Solution becomes lighter, brownish, or precipitate forms
  • Solution clears and becomes colorless rapidly
  • Solution turns green

Correct Answer: Solution becomes lighter, brownish, or precipitate forms

Q30. Which hazard classification applies to potassium permanganate in storage and transport?

  • Oxidizing agent hazard
  • Flammable liquid hazard
  • Explosive primary hazard
  • Non-hazardous commodity

Correct Answer: Oxidizing agent hazard

Q31. Which pharmacopoeial parameter is important when evaluating KMnO4 for pharmaceutical use?

  • Assay for permanganate content and absence of reducing impurities
  • Water activity only
  • Particle shape exclusively
  • Viscosity measurement

Correct Answer: Assay for permanganate content and absence of reducing impurities

Q32. Which statement about topical systemic absorption of KMnO4 is correct?

  • Large systemic absorption is typical from intact skin
  • Minimal systemic absorption from intact skin; more risk on denuded surfaces
  • KMnO4 is rapidly metabolized to active drug systemically
  • KMnO4 acts as a prodrug for systemic antibiotics

Correct Answer: Minimal systemic absorption from intact skin; more risk on denuded surfaces

Q33. Which laboratory safety measure is critical when handling KMnO4 powder?

  • Wear non-reactive gloves and eye protection to avoid contact and inhalation
  • Use bare hands to measure small amounts
  • Mix near open flames to speed dissolution
  • Store next to organic solvents for convenience

Correct Answer: Wear non-reactive gloves and eye protection to avoid contact and inhalation

Q34. Which of the following best describes the effect of KMnO4 on fungal cell walls?

  • Inhibition of ergosterol synthesis only
  • Oxidative damage to cell wall components and membranes
  • Promotion of fungal growth
  • Selective inhibition of protein synthesis

Correct Answer: Oxidative damage to cell wall components and membranes

Q35. Why should KMnO4 solutions not be mixed with hydrogen peroxide in practice?

  • They form a stable complex increasing antiseptic potency
  • They can react vigorously, producing oxygen and heat
  • They neutralize each other to harmless water
  • They form a therapeutic ointment

Correct Answer: They can react vigorously, producing oxygen and heat

Q36. Which patient counseling point is appropriate for topical KMnO4 use?

  • Apply concentrated crystals directly to skin
  • Expect temporary skin discoloration and rinse thoroughly after soak
  • Ingest a small amount to treat throat infections
  • Use with petroleum jelly immediately to enhance penetration

Correct Answer: Expect temporary skin discoloration and rinse thoroughly after soak

Q37. In compounding, which solvent is appropriate for dissolving KMnO4 for topical use?

  • Water (distilled or purified)
  • Ether
  • Alcoholic solvents only
  • Mineral oil

Correct Answer: Water (distilled or purified)

Q38. Which analytical observation indicates complete titration end point in permanganometry without external indicator?

  • Solution turns permanently colorless
  • First permanent faint pink/purple color persists
  • Formation of white precipitate
  • Solution becomes milky

Correct Answer: First permanent faint pink/purple color persists

Q39. Which is a common topical formulation method for KMnO4 in pharmacy practice?

  • Ointment with KMnO4 crystals
  • Dilute aqueous soaks or wet dressings
  • Oil-based lotion
  • Intravenous infusion

Correct Answer: Dilute aqueous soaks or wet dressings

Q40. Which of the following organisms is least likely to be susceptible to topical KMnO4?

  • Certain spore-forming bacteria
  • Common dermatophyte fungi
  • Non-spore-forming Gram-positive bacteria
  • Certain gram-negative bacteria

Correct Answer: Certain spore-forming bacteria

Q41. Which clinical scenario requires caution or avoidance of KMnO4 use?

  • Superficial weeping eczema
  • Children with widespread blistering or large raw areas
  • Interdigital fungal infections
  • Localized vesicular hand dermatitis

Correct Answer: Children with widespread blistering or large raw areas

Q42. Which environmental precaution is important when disposing of KMnO4 solutions?

  • Pour concentrated solutions into organic waste
  • Neutralize oxidizing capacity and dilute before controlled disposal per regulations
  • Dispose by burning with organic materials
  • Dump directly into septic systems

Correct Answer: Neutralize oxidizing capacity and dilute before controlled disposal per regulations

Q43. Which chemical reduction product of permanganate is insoluble and causes staining?

  • Manganese dioxide (MnO2)
  • Manganese sulfate
  • Manganese chloride
  • Manganese metal

Correct Answer: Manganese dioxide (MnO2)

Q44. Which formulation parameter influences the shelf life of an aqueous KMnO4 solution?

  • Presence of organic contaminants and light exposure
  • Use of glass container only
  • Color of the label
  • Room temperature variations within 0.5°C

Correct Answer: Presence of organic contaminants and light exposure

Q45. In pharmaceutical chemistry, permanganate is often used as a test reagent for which functional group?

  • Alkanes
  • Unsaturated groups like alkenes and alcohols (oxidizable groups)
  • Alkyl halides only
  • Noble gases

Correct Answer: Unsaturated groups like alkenes and alcohols (oxidizable groups)

Q46. Which occupational health measure reduces risk for pharmacists preparing KMnO4 solutions?

  • Preparation on wooden benches near combustibles
  • Use of personal protective equipment and spill kits for oxidizers
  • Wearing synthetic gloves that may react with oxidizer
  • Heating the powder to speed dissolution

Correct Answer: Use of personal protective equipment and spill kits for oxidizers

Q47. Which clinical effect explains the use of KMnO4 in reducing malodor of infected exudative lesions?

  • KMnO4 enhances bacterial odor production
  • Oxidative elimination of odor-causing organic compounds and microbes
  • KMnO4 binds odor molecules permanently
  • It masks odor with a strong scent

Correct Answer: Oxidative elimination of odor-causing organic compounds and microbes

Q48. Which storage condition could accelerate decomposition or loss of potency of KMnO4 crystals?

  • Storage in sealed non-reactive bottles in dry area
  • Storage mixed with reducing impurities or organic matter
  • Storage protected from light
  • Storage at controlled moderate temperature

Correct Answer: Storage mixed with reducing impurities or organic matter

Q49. Which reason justifies avoiding application of KMnO4 to the eyes?

  • It is a lubricating ophthalmic agent
  • It is highly irritating and can cause chemical injury to ocular tissue
  • It improves vision when diluted
  • It acts as a steroid for ocular inflammation

Correct Answer: It is highly irritating and can cause chemical injury to ocular tissue

Q50. For exam preparation, which study focus will best help B. Pharm students understand KMnO4 as an antimicrobial?

  • Only memorizing brand names
  • Understanding chemical oxidizing mechanism, clinical indications, concentrations, safety, and incompatibilities
  • Focusing solely on systemic pharmacokinetics
  • Learning unrelated topical antibiotics

Correct Answer: Understanding chemical oxidizing mechanism, clinical indications, concentrations, safety, and incompatibilities

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