Structure and uses of ethanolamine MCQs With Answer

Ethanolamine (2‑aminoethanol or monoethanolamine, MEA) is a small bifunctional molecule containing both a primary amine and a primary alcohol group. Understanding the structure and uses of ethanolamine is crucial for B. Pharm students studying pharmaceutical chemistry, excipient selection, synthesis of active pharmaceutical intermediates, and formulation science. Key topics include molecular structure, pKa and basicity, solubility, reactivity with acids and acylating agents, industrial production from ethylene oxide, and applications in buffers, emulsifiers, surfactants, and drug synthesis. This introduction highlights practical and safety aspects relevant to formulation and medicinal chemistry. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the IUPAC name of ethanolamine?

• 2‑aminoethanol
• ethanolamine chloride
• ethanamide
• 1‑aminoethanol

Correct Answer: 2‑aminoethanol

Q2. What is the molecular formula of ethanolamine?

• C2H7NO
• C3H9NO
• C2H6O
• C2H5NH2

Correct Answer: C2H7NO

Q3. Which functional groups are present in ethanolamine?

• Primary amine and primary alcohol
• Secondary amine and secondary alcohol
• Carboxylic acid and amide
• Aldehyde and ether

Correct Answer: Primary amine and primary alcohol

Q4. Ethanolamine is amphiphilic because it contains:

• Hydrophilic amine and hydrophobic long alkyl chain
• Hydrophilic amine and hydrophilic hydroxyl groups
• Only hydrophobic groups
• Only aromatic rings

Correct Answer: Hydrophilic amine and hydrophilic hydroxyl groups

Q5. The conjugate acid pKa of ethanolamine is approximately:

• 9.5
• 4.8
• 13.0
• 7.0

Correct Answer: 9.5

Q6. Ethanolamine is industrially produced mainly by reacting ethylene oxide with:

• Ammonia
• Sodium hydroxide
• Hydrochloric acid
• Acetic acid

Correct Answer: Ammonia

Q7. Which property makes ethanolamine useful as a CO2 absorbent in gas treatment?

• Its basic amine reacts reversibly with CO2 to form carbamates/bicarbonates
• Its hydrophobicity promotes CO2 solubility
• It polymerizes CO2 permanently
• It oxidizes CO2 to CO

Correct Answer: Its basic amine reacts reversibly with CO2 to form carbamates/bicarbonates

Q8. Which derivative of ethanolamine is commonly used as an emulsifier and in cosmetics?

• Triethanolamine (TEA)
• Ethylamine
• Diethylamine
• Acetone

Correct Answer: Triethanolamine (TEA)

Q9. Which reaction describes ethanolamine forming an amide?

• Acylation of the amine with an acyl chloride or anhydride
• Oxidation of the alcohol group
• Hydrogenation of the alkyl chain
• Dehydration to form an alkene

Correct Answer: Acylation of the amine with an acyl chloride or anhydride

Q10. Ethanolamine can act as a buffer component because:

• Its conjugate acid/base pair has a pKa near physiological/basic range
• It is a strong acid
• It is insoluble in water
• It does not ionize

Correct Answer: Its conjugate acid/base pair has a pKa near physiological/basic range

Q11. In terms of toxicity and safety, ethanolamine is best described as:

• An irritant that can cause skin and respiratory irritation
• Non‑irritant and completely safe at any concentration
• A highly explosive gas
• A strong oxidizing agent

Correct Answer: An irritant that can cause skin and respiratory irritation

Q12. Which bond connectivity represents ethanolamine structure?

• HO‑CH2‑CH2‑NH2
• NH2‑CH2‑CH3‑OH
• HO‑CH‑NH‑CH3
• CH3‑CH2‑NH‑CH2‑OH

Correct Answer: HO‑CH2‑CH2‑NH2

Q13. Ethanolamine is miscible with water because:

• It forms hydrogen bonds via both NH and OH groups
• It is highly nonpolar
• It forms ionic salts only
• It sublimes easily

Correct Answer: It forms hydrogen bonds via both NH and OH groups

Q14. Which pharmaceutical application uses ethanolamine derivatives as local anesthetics precursors?

• Synthesis of amino ester or amino amide local anesthetics
• Anticoagulant therapy
• Antihypertensive drugs directly
• Radiocontrast agents

Correct Answer: Synthesis of amino ester or amino amide local anesthetics

Q15. Which analytical technique is most appropriate to confirm the presence of both NH and OH groups in ethanolamine?

• Infrared (IR) spectroscopy showing N–H and O–H stretches
• UV‑Vis spectroscopy only
• Atomic absorption spectroscopy
• X‑ray crystallography only

Correct Answer: Infrared (IR) spectroscopy showing N–H and O–H stretches

Q16. How does ethanolamine react with aldehydes under typical conditions?

• Forms imines (Schiff bases) via condensation at the amine
• Undergoes esterification at the alcohol only
• Is oxidized to CO2
• Does not react with aldehydes

Correct Answer: Forms imines (Schiff bases) via condensation at the amine

Q17. Which parameter is directly affected when ethanolamine is used as an excipient in topical formulations?

• pH adjustment and emulsification
• Color enhancement only
• Radioactivity level
• Melting point of active only

Correct Answer: pH adjustment and emulsification

Q18. Ethanolamine reacts with fatty acids to form:

• Fatty acid salts and amides useful as surfactants
• Alkanes via reduction
• Polymers that are inert
• Inorganic salts only

Correct Answer: Fatty acid salts and amides useful as surfactants

Q19. Which statement about monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) is correct?

• MEA has one ethanol group attached to nitrogen; DEA has two; TEA has three
• All three are identical in functionality
• DEA is monofunctional while MEA is trifunctional
• TEA contains no nitrogen

Correct Answer: MEA has one ethanol group attached to nitrogen; DEA has two; TEA has three

Q20. Which property distinguishes ethanolamine from a simple primary amine like ethylamine?

• Presence of a hydroxyl group enabling intramolecular hydrogen bonding and additional reactivity
• Ethanolamine is nonpolar while ethylamine is polar
• Ethanolamine lacks basicity entirely
• Ethylamine contains an alcohol group

Correct Answer: Presence of a hydroxyl group enabling intramolecular hydrogen bonding and additional reactivity

Q21. In drug synthesis, ethanolamine is commonly used as a:

• Nucleophilic building block providing both amine and hydroxyl functionalities
• Strong oxidizing reagent
• Protecting group for ketones
• Nonreactive diluent

Correct Answer: Nucleophilic building block providing both amine and hydroxyl functionalities

Q22. What is a common chemical hazard when storing ethanolamine with oxidizers?

• Risk of exothermic reaction and decomposition
• Complete inertness with no hazard
• Formation of stable complexes that prevent reaction
• Spontaneous polymerization to polyethylene

Correct Answer: Risk of exothermic reaction and decomposition

Q23. Which solvent property makes ethanolamine a useful solvent for CO2 capture systems?

• High water miscibility and basicity to absorb acidic gases
• Inertness toward gases
• Low boiling point below 0 °C
• Nonpolar character

Correct Answer: High water miscibility and basicity to absorb acidic gases

Q24. The boiling point of ethanolamine at atmospheric pressure is approximately:

• 170 °C
• 78 °C
• 25 °C
• 300 °C

Correct Answer: 170 °C

Q25. Which spectroscopic signal would you expect for the OH proton of ethanolamine in 1H NMR in D2O?

• It will exchange with D2O and typically disappear
• It gives a sharp triplet at 7 ppm
• It appears as a strong singlet at 10 ppm
• It forms a carbonyl peak

Correct Answer: It will exchange with D2O and typically disappear

Q26. Which pH adjustment role can ethanolamine play in topical pharmaceutical creams?

• Neutralize acidic ingredients and stabilize pH toward basic side
• Act as a strong acid to lower pH dramatically
• Eliminate need for preservatives entirely
• Prevent oxidation of actives by acting as an antioxidant

Correct Answer: Neutralize acidic ingredients and stabilize pH toward basic side

Q27. Which type of reaction would convert ethanolamine into an ether derivative?

• Alkylation of the hydroxyl group under Williamson ether synthesis conditions
• Oxidation of the amine to a nitro group
• Hydrolysis with strong acid
• Deamination to form a ketone

Correct Answer: Alkylation of the hydroxyl group under Williamson ether synthesis conditions

Q28. Ethanolamine forms salts with acids. Which salt is commonly used for isolation and purification?

• Hydrochloride salt (ethanolamine hydrochloride)
• Sodium ethoxide salt
• Calcium carbonate salt
• Neutral acetate ester

Correct Answer: Hydrochloride salt (ethanolamine hydrochloride)

Q29. Which reagent selectively acetylates the amine of ethanolamine to form N‑acetylethanolamine?

• Acetic anhydride
• Sodium borohydride
• Hydrochloric acid
• Oxone

Correct Answer: Acetic anhydride

Q30. In pharmaceutical formulations, what is a potential regulatory concern with ethanolamine and its derivatives?

• Formation of nitrosamines if nitrosating agents are present
• They are universally banned in all countries
• They always cause severe systemic toxicity at trace levels
• They are completely nonreactive and thus unregulated

Correct Answer: Formation of nitrosamines if nitrosating agents are present

Q31. Which mechanism best explains ethanolamine’s basicity?

• Protonation of the lone pair on nitrogen to form a conjugate acid
• Deprotonation of the hydroxyl to form an oxide ion
• Oxidative addition to metal centers
• Formation of carbocations spontaneously

Correct Answer: Protonation of the lone pair on nitrogen to form a conjugate acid

Q32. Which is a common impurity when producing ethanolamine from ethylene oxide and ammonia?

• Diethanolamine and triethanolamine (higher substituted products)
• Pure water only
• Simple alkanes like pentane
• Inorganic silica

Correct Answer: Diethanolamine and triethanolamine (higher substituted products)

Q33. What type of pharmaceutical excipient role can ethanolamine derivatives perform?

• Surfactants and emulsifying agents
• Primary active antiviral agents
• Radioactive tracers
• Nonadsorbing fillers only

Correct Answer: Surfactants and emulsifying agents

Q34. Ethanolamine can chelate metal ions to some extent due to:

• Presence of donor atoms (N and O) that can coordinate metals
• Its large aromatic system
• Being a strong oxidant that removes metals
• Its purely hydrophobic nature

Correct Answer: Presence of donor atoms (N and O) that can coordinate metals

Q35. Which laboratory test would you use to quantify ethanolamine concentration in a formulation?

• Titration with standard acid or chromatographic methods (HPLC)
• Simple melting point determination
• X‑ray fluorescence only
• Polarimetry only

Correct Answer: Titration with standard acid or chromatographic methods (HPLC)

Q36. Ethanolamine’s miscibility with organic solvents is best described as:

• Miscible with water and many polar organic solvents, less with nonpolar solvents
• Completely immiscible with all solvents
• Only soluble in hexane
• Soluble only in supercritical CO2

Correct Answer: Miscible with water and many polar organic solvents, less with nonpolar solvents

Q37. Which biological effect is ethanolamine associated with as a metabolite or precursor?

• Precursor for phosphatidylethanolamine in membrane phospholipid biosynthesis
• Direct inhibition of DNA polymerase at nanomolar levels
• Conversion to glucose in glycolysis
• Formation of hemoglobin

Correct Answer: Precursor for phosphatidylethanolamine in membrane phospholipid biosynthesis

Q38. Which protective group strategy can be used to protect the amine of ethanolamine during multi‑step synthesis?

• Boc (tert‑butoxycarbonyl) protection of the amine
• Direct chlorination without protection
• Complete hydrogenation of both groups
• Irreversible oxidation to nitro without regeneration

Correct Answer: Boc (tert‑butoxycarbonyl) protection of the amine

Q39. Which statement about the hydrogen bonding in ethanolamine is true?

• It can form both intra- and intermolecular hydrogen bonds affecting boiling point and solubility
• It cannot form hydrogen bonds at all
• Hydrogen bonding causes ethanolamine to be a gas at room temperature
• Hydrogen bonds convert it to an aromatic compound

Correct Answer: It can form both intra- and intermolecular hydrogen bonds affecting boiling point and solubility

Q40. When converting ethanolamine to a carbamate for drug delivery, which reagent is commonly used?

• Phosgene or its safer alternatives (for carbamate formation)
• Sodium chloride only
• Hydrochloric acid without base
• Elemental sulfur

Correct Answer: Phosgene or its safer alternatives (for carbamate formation)

Q41. Which analytical hazard arises from ethanolamine reacting with nitrosating agents during drug manufacturing?

• Potential formation of N‑nitrosamines, which are genotoxic impurities
• Immediate explosive decomposition into nitrogen gas
• Complete inactivation of all active pharmaceutical ingredients
• Conversion into stable sugars

Correct Answer: Potential formation of N‑nitrosamines, which are genotoxic impurities

Q42. Which is the correct classification of ethanolamine in terms of amine type?

• Primary alkanolamine (primary amine)
• Quaternary ammonium salt
• Tertiary amine
• Secondary aliphatic amine

Correct Answer: Primary alkanolamine (primary amine)

Q43. Ethanolamine’s role in formulation stability can include:

• Acting as a pH regulator to stabilize active ingredients
• Automatically sterilizing the product
• Turning liquid formulations into solids instantly
• Removing active drug from solution irreversibly

Correct Answer: Acting as a pH regulator to stabilize active ingredients

Q44. Which reagent would selectively oxidize the primary alcohol of ethanolamine to an aldehyde while preserving the amine?

• PCC (pyridinium chlorochromate) under controlled conditions
• Strong base like NaOH only
• Hydrogen gas with Pd/C (would reduce instead)
• Conc. HCl at high temperature

Correct Answer: PCC (pyridinium chlorochromate) under controlled conditions

Q45. Why is controlling the concentration of ethanolamine important in pharmaceutical formulations?

• High concentrations can cause irritation and affect stability of ingredients
• Higher concentrations always increase therapeutic efficacy
• Concentration has no impact on product performance
• Only trace amounts are explosive

Correct Answer: High concentrations can cause irritation and affect stability of ingredients

Q46. Which chromatographic technique is commonly used to separate ethanolamine from its DEA and TEA homologs?

• Ion‑exchange or HPLC methods tailored for amines
• Thin layer chromatography using nonpolar solvent exclusively
• Gel electrophoresis only
• Ultracentrifugation

Correct Answer: Ion‑exchange or HPLC methods tailored for amines

Q47. Which reaction would yield N,N‑diethanolamine from ethanolamine or intermediates?

• Further alkylation of the nitrogen with additional ethylene oxide equivalents
• Simple esterification of the alcohol group only
• Complete catalytic hydrogenation to propane derivatives
• Oxidative cleavage to give formaldehyde

Correct Answer: Further alkylation of the nitrogen with additional ethylene oxide equivalents

Q48. In safety data sheets, ethanolamine is typically assigned which hazard pictogram for acute toxicity and irritation?

• Exclamation mark (irritant) and corrosion depending on concentration
• Flame only
• Exploding bomb only
• Environmental hazard only

Correct Answer: Exclamation mark (irritant) and corrosion depending on concentration

Q49. Ethanolamine can be used to prepare which class of biologically relevant lipids?

• Phosphatidylethanolamines (PE) via attachment to glycerophospholipids
• Sphingomyelins exclusively
• Cholesteryl esters only
• Triglycerides without further modification

Correct Answer: Phosphatidylethanolamines (PE) via attachment to glycerophospholipids

Q50. Which storage condition is appropriate to minimize degradation of ethanolamine?

• Store in cool, well‑ventilated area away from strong oxidizers and acids
• Store in direct sunlight at high temperature
• Mix with strong acids and leave open to air
• Keep at high humidity and heat

Correct Answer: Store in cool, well‑ventilated area away from strong oxidizers and acids

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