Structure and uses of Chloramine MCQs With Answer

Introduction: Chloramine is an important disinfectant and synthetic reagent studied under the topic Structure and uses of Chloramine MCQs With Answer for B. Pharm students. This overview covers structural types—monochloramine (NH2Cl) and organic chloramines such as chloramine‑T (sodium N‑chloro‑p‑toluenesulfonamide)—their N–Cl functional group, stability, reactivity and pharmaceutical applications. Key uses include water disinfection, protein iodination in analytical chemistry, and selective oxidation in organic synthesis. Understanding formation conditions, mechanisms, safety, and neutralization methods is essential for lab and clinical practice. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which of the following is the simplest chloramine species formed when chlorine reacts with ammonia?

• Chloramine‑T
• Monochloramine (NH2Cl)
• Dichloramine (NHCl2)
• Trichloramine (NCl3)

Correct Answer: Monochloramine (NH2Cl)

Q2. What is the chemical name of chloramine‑T commonly used in laboratories?

• Sodium hypochlorite
• Sodium N‑chloro‑p‑toluenesulfonamide
• Trichloroisocyanuric acid
• Monochloramine

Correct Answer: Sodium N‑chloro‑p‑toluenesulfonamide

Q3. What is the molecular formula commonly given for chloramine‑T (anhydrous)?

• C7H7ClNNaO2S
• NH2Cl
• Cl2
• C6H5Cl

Correct Answer: C7H7ClNNaO2S

Q4. Which functional group characterizes chloramine‑T’s reactivity?

• Carbonyl group
• N–Cl (N‑chloro sulfonamide)
• Epoxide ring
• Thiol group

Correct Answer: N–Cl (N‑chloro sulfonamide)

Q5. In water treatment, why are chloramines (especially monochloramine) used instead of free chlorine?

• They produce strong odor and taste
• They provide longer residual disinfectant stability in distribution systems
• They create more trihalomethanes (THMs)
• They are more reactive toward organic material

Correct Answer: They provide longer residual disinfectant stability in distribution systems

Q6. Which pH range favors formation of monochloramine over dichloramine or trichloramine?

• pH 3–4
• pH 5–6
• pH 7–8
• pH 11–12

Correct Answer: pH 7–8

Q7. Chloramine‑T is commonly used in biochemical labs to:

• Reduce disulfide bonds in proteins
• Oxidize iodide to iodine for iodination of tyrosine residues
• Denature DNA
• Polymerize peptides

Correct Answer: Oxidize iodide to iodine for iodination of tyrosine residues

Q8. The main oxidizing species generated from chloramine‑T during iodination reactions is:

• Hydroxyl radical
• Free chlorine gas
• Active electrophilic iodine (I+ or I2)
• Peroxide anion

Correct Answer: Active electrophilic iodine (I+ or I2)

Q9. Which structural feature makes chloramine‑T a stable, easy‑to‑handle solid reagent?

• Presence of a bulky alkyl chain without ionic character
• It is an N‑chloro sulfonamide sodium salt providing ionic stabilization
• It contains a peroxy linkage stabilizing chlorine
• It is gaseous at room temperature

Correct Answer: It is an N‑chloro sulfonamide sodium salt providing ionic stabilization

Q10. Compared to sodium hypochlorite, chloramine‑T in organic synthesis is primarily valued for:

• Being a strong reducing agent
• Selective chlorination/oxidation with mild conditions
• Generating free chlorine for broad oxidation
• Forming stable radicals for polymerization

Correct Answer: Selective chlorination/oxidation with mild conditions

Q11. Which hazardous by‑product is more associated with free chlorine disinfection than with chloramination?

• Nitrosamines
• Trihalomethanes (THMs)
• Chloramines
• Nitrites

Correct Answer: Trihalomethanes (THMs)

Q12. A major potential concern of chloramination in water systems is formation of:

• Excess free iodine
• Nitrosamines (e.g., NDMA)
• High levels of ozone
• Nitrogen gas bubbles

Correct Answer: Nitrosamines (e.g., NDMA)

Q13. The N–Cl bond in chloramine‑T is best described as:

• A strong covalent C–Cl bond
• An ionic bond between N+ and Cl−
• An electrophilic N–Cl bond capable of delivering positive chlorine
• A hydrogen bond acceptor

Correct Answer: An electrophilic N–Cl bond capable of delivering positive chlorine

Q14. Which reagent is commonly used to quench or neutralize residual chloramine or free chlorine in water samples before biochemical assays?

• Sodium chloride
• Sodium thiosulfate
• Hydrochloric acid
• Sodium bicarbonate

Correct Answer: Sodium thiosulfate

Q15. In protein iodination with chloramine‑T, the iodination primarily occurs at which amino acid residue?

• Lysine
• Tyrosine
• Alanine
• Proline

Correct Answer: Tyrosine

Q16. Which of the following is a correct description of monochloramine’s antimicrobial action?

• It acts only by physical filtration
• It is a stable chlorinating agent that penetrates biofilms slowly and inactivates microbes
• It instantly sterilizes all surfaces like chlorine gas
• It reduces pH to kill bacteria

Correct Answer: It is a stable chlorinating agent that penetrates biofilms slowly and inactivates microbes

Q17. Which reagent can neutralize chloramine residues in IV lines to protect patients from hemolysis or toxicity?

• Sodium nitrite
• Ascorbic acid (vitamin C)
• Concentrated hydrogen peroxide
• Ammonium chloride

Correct Answer: Ascorbic acid (vitamin C)

Q18. In an iodination assay using chloramine‑T, the role of iodide (I−) is to:

• Act as a reducing agent to regenerate chloramine
• Serve as substrate to be oxidized to electrophilic iodine for substitution
• Complex with proteins to prevent iodination
• Buffer the reaction pH

Correct Answer: Serve as substrate to be oxidized to electrophilic iodine for substitution

Q19. Which statement best compares chloramine‑T and chloramine (monochloramine) identity?

• They are identical compounds with the same uses
• Chloramine‑T is an organic N‑chloro sulfonamide salt; monochloramine is NH2Cl, a simple inorganic chloramine
• Both are inorganic gases at room temperature
• Chloramine‑T is gaseous while monochloramine is solid

Correct Answer: Chloramine‑T is an organic N‑chloro sulfonamide salt; monochloramine is NH2Cl, a simple inorganic chloramine

Q20. Which analytical technique commonly uses chloramine‑T for labeling or detection purposes?

• Mass spectrometry without derivatization
• Radioiodination of proteins for tracer studies
• Gas chromatography of hydrocarbons
• Titration of strong acids only

Correct Answer: Radioiodination of proteins for tracer studies

Q21. Which of the following is a typical advantage of chloramination in municipal water supply?

• Higher formation of regulated THMs compared with chlorine
• More persistent residual disinfectant with lower THM formation
• Immediate stronger disinfection but shorter residual life
• Complete elimination of disinfection by‑products

Correct Answer: More persistent residual disinfectant with lower THM formation

Q22. What color or physical form is chloramine‑T typically found as?

• Colorless gas
• Yellow crystalline solid or powder
• Dark brown liquid
• Green oily liquid

Correct Answer: Yellow crystalline solid or powder

Q23. Which reagent would most likely decompose the N–Cl bond in chloramine‑T by nucleophilic attack?

• Sodium cyanide (CN−)
• Sodium azide (N3−)
• Thiolates or sulfide nucleophiles
• Inert noble gas

Correct Answer: Thiolates or sulfide nucleophiles

Q24. During preparation of monochloramine in water, what stoichiometry of chlorine to ammonia is typically targeted to favor monochloramine?

• 3:1 (Cl2:NH3)
• 1:3 (Cl2:NH3)
• 1:1 (Cl2:NH3)
• 0.1:1 (Cl2:NH3)

Correct Answer: 1:1 (Cl2:NH3)

Q25. Which mechanism best describes iodination of tyrosine by chloramine‑T oxidized iodine?

• Nucleophilic aromatic substitution at a deactivated ring
• Electrophilic aromatic substitution on the phenolic ring
• Radical chlorination of aliphatic side chain
• Pericyclic cycloaddition

Correct Answer: Electrophilic aromatic substitution on the phenolic ring

Q26. What safety precaution is especially important when handling chloramine‑T powder in the lab?

• Avoid exposure to oxygen as it is pyrophoric
• Use gloves and eye protection to prevent skin and eye irritation from N‑chloro compounds
• Keep it submerged in water
• Always store at high pH to stabilize

Correct Answer: Use gloves and eye protection to prevent skin and eye irritation from N‑chloro compounds

Q27. Chloramine formation in potable water is most likely when:

• There is a high free chlorine dose but no ammonia present
• Free chlorine is added in the presence of ammonia or organic nitrogen compounds
• Only ozone is used for disinfection
• Water is boiled vigorously

Correct Answer: Free chlorine is added in the presence of ammonia or organic nitrogen compounds

Q28. Which of the following best describes chloramine‑T’s role in organic synthesis?

• Harsh reducing agent for nitriles
• Mild oxidant and source of electrophilic chlorine for selective transformations
• Strong acid catalyst for esterification
• Radical initiator for polymerization

Correct Answer: Mild oxidant and source of electrophilic chlorine for selective transformations

Q29. Which by‑product formation increases when switching from free chlorine to chloramine treatment for disinfection?

• Higher total trihalomethanes (THMs)
• More inorganic chlorides only
• Potential increase in certain nitrogen‑containing disinfection by‑products (e.g., nitrosamines)
• Complete elimination of all by‑products

Correct Answer: Potential increase in certain nitrogen‑containing disinfection by‑products (e.g., nitrosamines)

Q30. In an iodination protocol using chloramine‑T, which component is used to stop the reaction and remove excess oxidant?

• Excess iodide
• Reducing agent such as sodium metabisulfite or thiosulfate
• Concentrated acid to denature proteins
• Calcium carbonate

Correct Answer: Reducing agent such as sodium metabisulfite or thiosulfate

Q31. Which of the following statements about trichloramine (NCl3) in water systems is true?

• It is more soluble and less odorous than monochloramine
• It is volatile and associated with strong odor and irritation in indoor pools
• It is a desired disinfectant in drinking water
• It forms predominantly at very high pH

Correct Answer: It is volatile and associated with strong odor and irritation in indoor pools

Q32. What analytical property makes chloramine‑T useful in radioiodination of proteins for tracer studies?

• Its ability to fluoresce under UV
• Its capacity to oxidize iodide to electrophilic iodine under mild, controllable conditions
• Its high volatility for gas‑phase labeling
• Its inertness preventing any reaction

Correct Answer: Its capacity to oxidize iodide to electrophilic iodine under mild, controllable conditions

Q33. Which factor does NOT significantly affect monochloramine stability in water?

• pH of the water
• Temperature
• Presence of sunlight (UV exposure)
• Color of the water bottle cap

Correct Answer: Color of the water bottle cap

Q34. How does chloramine‑T compare to N‑chlorosuccinimide (NCS) in chlorination reactions?

• Both are N‑chloro reagents but differ in solubility, selectivity and by‑products
• Chloramine‑T is always more reactive than NCS
• NCS is identical in structure to chloramine‑T
• Neither can transfer electrophilic chlorine

Correct Answer: Both are N‑chloro reagents but differ in solubility, selectivity and by‑products

Q35. What is a common industrial source of monochloramine formation that can impact drinking water?

• Natural release from limestone
• Reaction of free chlorine with ammonia from wastewater or decaying organic nitrogen
• Emission from diesel engines
• Chlorine gas leaking from refrigerators

Correct Answer: Reaction of free chlorine with ammonia from wastewater or decaying organic nitrogen

Q36. Which reagent is least appropriate to remove chloramine from water intended for cell culture?

• Activated carbon filtration
• Ascorbic acid (vitamin C)
• Direct addition of concentrated bleach
• Sodium thiosulfate

Correct Answer: Direct addition of concentrated bleach

Q37. Which structural description applies to the aryl portion of chloramine‑T?

• A nitrobenzene ring without substituents
• A p‑toluenesulfonyl (p‑methylphenyl sulfonyl) moiety attached to N‑chloramide
• A biphenyl ether system
• An unsubstituted phenylalanine residue

Correct Answer: A p‑toluenesulfonyl (p‑methylphenyl sulfonyl) moiety attached to N‑chloramide

Q38. Which reaction condition is typically avoided when using chloramine‑T for selective oxidation?

• Mild neutral pH
• High concentrations of strong nucleophiles like thiols
• Low temperature
• Stoichiometric control of reagent

Correct Answer: High concentrations of strong nucleophiles like thiols

Q39. What analytical precaution should be taken when measuring chlorine residuals in water that may contain chloramines?

• Use a method that detects only free chlorine and ignore combined chlorine
• Use methods that distinguish free chlorine from combined chlorine (chloramines)
• Assume total absence of chlorine
• Only measure pH as a proxy

Correct Answer: Use methods that distinguish free chlorine from combined chlorine (chloramines)

Q40. Which statement about chloramine infection control in hospitals is accurate?

• Chloramines are never used due to complete incompatibility with medical devices
• Monochloramine can maintain a persistent disinfectant residual in plumbing systems and reduce pathogens when managed properly
• Chloramines immediately eradicate all biofilms without further action
• Chloramination always increases corrosion to unsafe levels

Correct Answer: Monochloramine can maintain a persistent disinfectant residual in plumbing systems and reduce pathogens when managed properly

Q41. Which pharmaceutical laboratory procedure commonly employs chloramine‑T?

• Protein radioiodination for tracer studies or immunoassays
• Large scale hydrogenation of alkenes
• Neutral lipid extraction using hexane
• Freeze‑drying of peptides

Correct Answer: Protein radioiodination for tracer studies or immunoassays

Q42. Which compound is likely formed when chloramine‑T reacts with excess water under alkaline conditions?

• Stable N‑chloro sulfonamide persists indefinitely without change
• Hydrolysis giving sulfonamide and hypochlorite or chloride species
• Formation of elemental chlorine gas only
• Direct conversion to trichloramine

Correct Answer: Hydrolysis giving sulfonamide and hypochlorite or chloride species

Q43. For iodination reactions controlled by chloramine‑T, what parameter is most critical to limit over‑iodination?

• Excess protein concentration only
• Reaction time and stoichiometric control of chloramine‑T
• Using extreme temperatures above 100°C
• Adding more iodide after reaction

Correct Answer: Reaction time and stoichiometric control of chloramine‑T

Q44. Which statement about the environmental persistence of monochloramine is true?

• It is extremely volatile and disappears instantly
• It persists longer than free chlorine in distribution systems, providing residual protection
• It reacts immediately to form elemental nitrogen only
• It cannot exist in the presence of organic matter

Correct Answer: It persists longer than free chlorine in distribution systems, providing residual protection

Q45. Which oxidizing agent can be considered an alternative to chloramine‑T for gentle electrophilic iodination in labs?

• Potassium permanganate under strong acidic conditions
• Iodogen (1,3,4,6‑tetrachloro‑3α,6α‑diphenylglycouril)
• Concentrated nitric acid
• Elemental bromine gas

Correct Answer: Iodogen (1,3,4,6‑tetrachloro‑3α,6α‑diphenylglycouril)

Q46. What property of chloramine‑T makes it useful in selective oxidation of sulfides to sulfoxides?

• Its ability to act as a hydride donor
• Its controlled electrophilic chlorine transfer and moderate oxidizing strength
• Its inertness toward sulfur compounds
• Its strong basicity

Correct Answer: Its controlled electrophilic chlorine transfer and moderate oxidizing strength

Q47. Which indicator of chloramine presence might be observed in indoor swimming pools?

• No odor and absolutely no eye irritation
• Persistent ‘chlorine’ smell and eye/nose irritation due to combined chlorine like dichloramine or trichloramine
• Increase in water pH to 12
• Immediate precipitation of salts

Correct Answer: Persistent ‘chlorine’ smell and eye/nose irritation due to combined chlorine like dichloramine or trichloramine

Q48. Which reagent would likely interfere with chloramine‑T mediated iodination by rapidly consuming the oxidant?

• Buffered saline only
• High concentrations of reducing agents like sulfite or thiosulfate
• Non‑reactive sugars
• Inert salts such as NaCl at low concentration

Correct Answer: High concentrations of reducing agents like sulfite or thiosulfate

Q49. For safe disposal of unused chloramine‑T solution in small lab quantities, the recommended step is to:

• Pour into the sink without treatment
• Neutralize with a suitable reducing agent (e.g., sodium thiosulfate) and follow institutional waste procedures
• Incinerate immediately in a non‑controlled environment
• Evaporate to dryness on a bench top

Correct Answer: Neutralize with a suitable reducing agent (e.g., sodium thiosulfate) and follow institutional waste procedures

Q50. Which characterization technique would best confirm the presence of the p‑toluenesulfonyl moiety in chloramine‑T?

• NMR spectroscopy showing aromatic and methyl signals consistent with p‑tolyl sulfonyl group
• Measurement of melting point only
• Simple visual inspection
• Conductivity measurement alone

Correct Answer: NMR spectroscopy showing aromatic and methyl signals consistent with p‑tolyl sulfonyl group

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