Acidifiers: Ammonium chloride* MCQs With Answer

Acidifiers: Ammonium chloride* MCQs With Answer

Acidifiers such as ammonium chloride are essential in B. Pharm studies for their roles in urinary acidification, treating metabolic alkalosis, and influencing drug excretion. This concise, high-yield MCQ set covers chemistry, mechanism of action, pharmacokinetics, therapeutic applications, formulation and compounding considerations, incompatibilities, adverse effects, monitoring parameters, and patient counselling relevant to pharmacy practice. Questions focus on applied concepts—how ammonium chloride generates acid load, its metabolism, clinical precautions in hepatic or renal impairment, and practical points for dosage form design and stability. Use these items to deepen your conceptual understanding and exam readiness. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the chemical formula of ammonium chloride?

• NH4Cl
• NH3Cl
• NH4OH
• NH2Cl

Correct Answer: NH4Cl

Q2. Which ion primarily contributes to the acidifying effect of ammonium chloride?

• Chloride ion (Cl-)
• Ammonium ion (NH4+)
• Hydroxide ion (OH-)
• Nitrate ion (NO3-)

Correct Answer: Ammonium ion (NH4+)

Q3. How does ammonium chloride acidify systemic pH after oral administration?

• Direct release of hydrochloric acid in the stomach
• Metabolism of ammonium to urea with generation of H+ in the liver
• Conversion to nitric acid in plasma
• Binding bicarbonate in the gut preventing absorption

Correct Answer: Metabolism of ammonium to urea with generation of H+ in the liver

Q4. In clinical use, ammonium chloride is primarily indicated to:

• Alkalinize urine in metabolic acidosis
• Acidify urine and correct metabolic alkalosis
• Act as a diuretic by inhibiting carbonic anhydrase
• Serve as a primary antihypertensive agent

Correct Answer: Acidify urine and correct metabolic alkalosis

Q5. Acidification of urine by ammonium chloride will increase renal excretion of which type of drugs?

• Strong acids
• Weak acids
• Weak bases
• Non-ionizable lipophilic drugs

Correct Answer: Weak bases

Q6. Which patient population is at higher risk of adverse effects from ammonium chloride due to impaired metabolism of ammonium?

• Patients with hepatic impairment
• Patients with hyperthyroidism
• Patients with acute pancreatitis
• Patients with controlled asthma

Correct Answer: Patients with hepatic impairment

Q7. What is a common metabolic disturbance produced by excess ammonium chloride administration?

• Metabolic alkalosis
• Respiratory alkalosis
• Metabolic acidosis
• Respiratory acidosis

Correct Answer: Metabolic acidosis

Q8. Ammonium chloride is often contraindicated in patients with:

• Renal failure where ammonium excretion is impaired
• Essential hypertension controlled on ACE inhibitors
• Iron deficiency anemia
• Hyperlipidemia on statins

Correct Answer: Renal failure where ammonium excretion is impaired

Q9. The molecular weight of ammonium chloride (approx.) is:

• 18 g/mol
• 53.5 g/mol
• 98 g/mol
• 23 g/mol

Correct Answer: 53.5 g/mol

Q10. Which route of elimination is most relevant for ammonium derived from ammonium chloride?

• Renal excretion as NH4+
• Fecal elimination unchanged
• Exhalation as ammonia gas
• Sequestration in adipose tissue

Correct Answer: Renal excretion as NH4+

Q11. Which laboratory parameter should be monitored when a patient receives therapeutic doses of ammonium chloride?

• Serum bicarbonate and blood pH
• Serum potassium only
• Serum lipase
• Fasting glucose

Correct Answer: Serum bicarbonate and blood pH

Q12. Ammonium chloride can interact with which of the following by altering urinary excretion?

• Antacids containing aluminum hydroxide only
• Weakly basic drugs such as amphetamines
• Topical antifungals with no renal excretion
• Insulin administered subcutaneously

Correct Answer: Weakly basic drugs such as amphetamines

Q13. In formulation chemistry, ammonium chloride is most correctly classified as a:

• Buffering alkali
• Acidifying agent (acidifier)
• Surfactant
• Preservative

Correct Answer: Acidifying agent (acidifier)

Q14. Which adverse effect is commonly associated with oral ammonium chloride therapy?

• Gastric irritation, nausea, and vomiting
• Constipation and dry mouth
• Hair loss and neuropathy
• Congestive heart failure exacerbation

Correct Answer: Gastric irritation, nausea, and vomiting

Q15. From a medicinal chemistry perspective, ammonium chloride is best described as:

• An organic weak acid
• An inorganic ammonium salt
• A quaternary ammonium compound
• A chelating agent

Correct Answer: An inorganic ammonium salt

Q16. When preparing a buffered syrup containing ammonium chloride, which excipient property is most critical?

• Compatibility with an ionic acidifier and pH stability
• High lipid solubility to enhance taste masking
• Ability to form a chelate with metal ions
• Strong oxidizing capacity

Correct Answer: Compatibility with an ionic acidifier and pH stability

Q17. Which of the following statements about ammonium chloride’s effect on weak acid drugs is correct?

• Urine acidification increases excretion of weak acids
• Urine acidification decreases excretion of weak acids
• Urine acidification has no effect on weak acids
• Urine acidification converts weak acids to bases

Correct Answer: Urine acidification decreases excretion of weak acids

Q18. In which clinical scenario might ammonium chloride be used therapeutically?

• To alkalinize urine in phenobarbital overdose
• To acidify urine in certain poisoning cases to increase weak base elimination
• As first-line treatment of diabetic ketoacidosis
• To replace sodium in hyponatremia

Correct Answer: To acidify urine in certain poisoning cases to increase weak base elimination

Q19. Ammonium chloride should be used with caution when co-administered with:

• Systemic alkalinizing agents such as sodium bicarbonate
• Topical emollients
• Inhaled bronchodilators without systemic effect
• Non-absorbed oral bulk laxatives only

Correct Answer: Systemic alkalinizing agents such as sodium bicarbonate

Q20. Which statement about ammonium chloride stability in aqueous solution is true?

• It is highly reactive and decomposes to ammonia within minutes at room temperature
• It is generally stable in neutral aqueous solutions but may hydrolyze slowly under strong alkalinity
• It readily oxidizes to nitrate in presence of light
• It polymerizes into insoluble chains in dilute solutions

Correct Answer: It is generally stable in neutral aqueous solutions but may hydrolyze slowly under strong alkalinity

Q21. A pharmaceutics student needs to assay ammonium chloride in a formulation. A classical approach involves:

• Titration of released chloride with silver nitrate
• Titration of ammonia after distillation with standard acid
• Colorimetric assay for organic ring structures
• Gravimetric determination of sulfate content

Correct Answer: Titration of ammonia after distillation with standard acid

Q22. Which organ is primarily responsible for converting ammonium from ammonium chloride into urea?

• Kidney
• Liver
• Spleen
• Pancreas

Correct Answer: Liver

Q23. In neonates or infants, ammonium chloride use demands caution mainly because of:

• Immature hepatic urea cycle and acid–base regulation
• Risk of causing growth retardation
• Poor palatability causing refusal to feed
• High protein-binding capacity

Correct Answer: Immature hepatic urea cycle and acid–base regulation

Q24. Which pharmacological classification best fits ammonium chloride?

• Urinary alkalinizing agent
• Urinary acidifying agent
• Loop diuretic
• Angiotensin-converting enzyme inhibitor

Correct Answer: Urinary acidifying agent

Q25. Which symptom could indicate overdosage of ammonium chloride?

• Severe metabolic acidosis with hyperventilation
• Marked hypoglycemia without acid–base change
• Sudden severe hypertension
• Painless jaundice

Correct Answer: Severe metabolic acidosis with hyperventilation

Q26. For compounding an effervescent granule formulation, inclusion of ammonium chloride requires attention to:

• Acid–base reaction with bicarbonate sources causing premature CO2 release
• Complexation with polyethylene glycol
• Oxidation by ascorbic acid producing chlorine gas
• Photodegradation into ammonia gas under fluorescent light

Correct Answer: Acid–base reaction with bicarbonate sources causing premature CO2 release

Q27. Which of the following best explains why ammonium chloride increases urinary NH4+ excretion?

• It is filtered and secreted as NH4+ in the renal tubules
• It inhibits renal ammoniagenesis leading to excretion
• It forms insoluble complexes that are excreted
• It is metabolized to chloride that is actively secreted

Correct Answer: It is filtered and secreted as NH4+ in the renal tubules

Q28. Which contraindication is most appropriate for ammonium chloride therapy?

• Uncompensated respiratory acidosis
• Severe metabolic alkalosis requiring acid load
• Significant hepatic failure with hyperammonemia
• Mild seasonal allergic rhinitis

Correct Answer: Significant hepatic failure with hyperammonemia

Q29. When counseling a patient on oral ammonium chloride tablets, which advice is important?

• Take with plenty of water and report GI irritation or persistent weakness
• Avoid all dairy products permanently while on therapy
• Stop sodium-containing foods completely
• Expect dramatic weight gain within 24 hours

Correct Answer: Take with plenty of water and report GI irritation or persistent weakness

Q30. In a drug interaction question: coadministration of ammonium chloride with a weakly basic antibiotic would most likely:

• Decrease its renal excretion and increase half-life
• Increase its renal excretion and decrease plasma concentration
• Convert it to an inactive metabolite via hepatic enzymes
• Have no effect on its excretion characteristics

Correct Answer: Increase its renal excretion and decrease plasma concentration

Q31. Which physicochemical property of ammonium chloride is most relevant to its use as an acidifier?

• High lipid solubility
• Provision of a readily dissociable ammonium ion
• Metal chelation ability
• Strong oxidizing power

Correct Answer: Provision of a readily dissociable ammonium ion

Q32. Which monitoring parameter is essential in long-term use of ammonium chloride?

• Serum chloride and acid–base balance
• Serum uric acid alone
• Serum magnesium only
• Serum amylase every 2 weeks

Correct Answer: Serum chloride and acid–base balance

Q33. Ammonium chloride is sometimes included in expectorant formulations historically because:

• It acts as a mucolytic by directly breaking disulfide bonds
• Urinary acidification relieves bronchospasm
• Ammonium salts were believed to increase respiratory secretions
• It acts as a local anesthetic in the airways

Correct Answer: Ammonium salts were believed to increase respiratory secretions

Q34. Which laboratory finding would you expect after therapeutic administration of ammonium chloride?

• Elevated serum bicarbonate
• Decreased serum bicarbonate and lower blood pH
• Elevated serum calcium due to bone resorption
• Marked neutrophilia without acid–base change

Correct Answer: Decreased serum bicarbonate and lower blood pH

Q35. In formulation compatibility testing, ammonium chloride may be incompatible with:

• Strong alkalies such as sodium hydroxide
• Neutral polymers like methylcellulose
• Sugar-based syrups at pH 5
• Hydrophilic solvents like glycerin

Correct Answer: Strong alkalies such as sodium hydroxide

Q36. Which statement about ammonium chloride use in pregnancy is most appropriate?

• It is absolutely contraindicated in all trimesters due to teratogenicity
• It should be used cautiously and only when benefits outweigh risks
• It is the preferred treatment for gestational diabetes
• It guarantees better fetal growth due to chloride supplementation

Correct Answer: It should be used cautiously and only when benefits outweigh risks

Q37. From a toxicology perspective, acute high-dose ammonium chloride poisoning may present with:

• CNS depression, vomiting, and severe acidosis
• Hypertension and bradycardia without GI symptoms
• Extreme hyperglycemia and polyuria only
• Isolated rash and pruritus without systemic signs

Correct Answer: CNS depression, vomiting, and severe acidosis

Q38. For a B. Pharm student, the primary teaching point about ammonium chloride’s renal handling is:

• It is reabsorbed in the proximal tubule as a neutral species
• NH4+ can substitute for H+ in tubular secretion and be excreted
• It is entirely metabolized before reaching the kidney
• It causes immediate diuresis by osmotic effect

Correct Answer: NH4+ can substitute for H+ in tubular secretion and be excreted

Q39. In a pharmaceutical quality control context, an impurity of concern in ammonium chloride batches would likely be:

• Residual ammonia or basic volatile amines
• Organic polymeric residues
• Heavy petroleum hydrocarbons
• High levels of dissolved oxygen

Correct Answer: Residual ammonia or basic volatile amines

Q40. Which statement about patient counselling for ammonium chloride is correct?

• Warn patients about possible drowsiness and advise against driving
• Advise patients to report symptoms of weakness, rapid breathing, or confusion
• Tell patients to avoid all fruits while taking the drug
• No counselling is necessary as it has no systemic effects

Correct Answer: Advise patients to report symptoms of weakness, rapid breathing, or confusion

Q41. Which biochemical pathway is most directly involved in processing the ammonium ion from ammonium chloride?

• Urea cycle in the liver
• Glycolysis in muscle tissue
• Beta-oxidation in adipose tissue
• Renin–angiotensin system in kidneys

Correct Answer: Urea cycle in the liver

Q42. In preparing a lecture slide on ammonium chloride, which keyword would best summarize its pharmaceutical role?

• Neutralizer
• Acidifier
• Emulsifier
• Antioxidant

Correct Answer: Acidifier

Q43. Which clinical test might be used to assess an excessive acid load after ammonium chloride administration?

• Arterial blood gas analysis
• Serum triglyceride measurement
• Electroencephalogram (EEG)
• Skin prick test

Correct Answer: Arterial blood gas analysis

Q44. Incompatibility of ammonium chloride with which excipient could lead to decreased acidifying action?

• Bicarbonate salts such as sodium bicarbonate
• Simple sugars like sucrose
• Flavoring agents like menthol
• Cellulose derivatives used as binders

Correct Answer: Bicarbonate salts such as sodium bicarbonate

Q45. Which of the following best describes ammonium chloride’s solubility?

• Poorly soluble in water
• Freely soluble in water
• Insoluble in most polar solvents
• Soluble only in organic solvents like hexane

Correct Answer: Freely soluble in water

Q46. Which precaution is most appropriate for an elderly patient prescribed ammonium chloride?

• Assess renal and hepatic function before and during therapy
• Increase dose without monitoring due to faster clearance
• Stop all other medications immediately
• Recommend high-protein diet to offset acid load

Correct Answer: Assess renal and hepatic function before and during therapy

Q47. In forensic toxicology, acidification of urine with ammonium chloride prior to drug extraction is done to:

• Enhance extraction of basic drugs by stabilizing their ionized form
• Convert all analytes to a volatile form for GC analysis
• Neutralize interfering proteins in the sample
• Remove salts that interfere with mass spectrometry

Correct Answer: Enhance extraction of basic drugs by stabilizing their ionized form

Q48. Which of the following is a correct statement about chronic use of ammonium chloride?

• It may lead to chronic metabolic acidosis and electrolyte disturbances
• It leads to chronic alkalosis and increased bicarbonate stores
• It prevents all renal calculi formation long-term
• It permanently enhances hepatic urea synthesis without side effects

Correct Answer: It may lead to chronic metabolic acidosis and electrolyte disturbances

Q49. When designing a shelf-life study for an ammonium chloride oral solution, the formulation scientist should pay special attention to:

• pH changes over time and microbial stability
• Color change due to protein denaturation
• Oxidation of tertiary amine groups
• Volatilization of elemental chlorine

Correct Answer: pH changes over time and microbial stability

Q50. Which exam-focused concept best summarizes why B. Pharm students must understand ammonium chloride?

• Its role as a rare antihypertensive with limited pharmacy relevance
• Its multifaceted importance in pharmacology, therapeutics, formulation, interactions, and patient safety
• Its use as a primary chemotherapeutic agent
• Its function as an inert filler in tablet manufacturing only

Correct Answer: Its multifaceted importance in pharmacology, therapeutics, formulation, interactions, and patient safety

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