M1 - Comprehensive Exam (Oct 2026)

D) The position and velocity of the electrons in the orbit cannot be determined simultaneously

Which of the following statements is not correct regarding Bohr’s model of hydrogen atom?
A. Energy of the electrons in the orbit is quantized
B. The electron in the orbit nearest to the nucleus has the lowest energy
C. Electrons revolve in different orbits around the nucleus
D. The position and velocity of the electrons in the orbit cannot be determined simultaneously

B) 3

If the maximum value of azimuthal quantum number (l) is 2 then the value of principal quantum number is:
A. 2
B. 3
C. 4
D. 5

A) 2 4 1 3

Match the quantum numbers given in Column I with the information provided by these given in Column II.
Codes: A B C D
A. 2 4 1 3
B. 3 2 4 1
C. 2 4 3 1
D. 1 2 3 4

B) 5p<6s<4f<5d

The correct order of increasing energy of atomic orbitals is
A. 5p

A) 3 5 1 4

Match the rules given in Column I with the statements provided in Column II.
Codes: A B C D
A. 3 5 1 4
B. 1 2 3 4
C. 2 1 3 4
D. 1 2 4 3

A) I

Out of the following electronic arrangements for outer electronic configuration.
The most stable arrangement is
A. I
B. II
C. III
D. IV

B) (C) < (B) < (A) < (D) < (E)

The increasing order of the atomic radii of the following elements is: (A) C (B) O (C) F (D) Cl (E) Br
A. (A) < (B) < (C) < (D) < (E)
B. (C) < (B) < (A) < (D) < (E)
C. (D) < (C) < (B) < (A) < (E)
D. (B) < (C) < (D) < (A) < (E)

D) 4 1 2 3

Match Column I with Column II and select the correct answer using given codes.
A. 4 2 3 1
B. 1 4 2 3
C. 4 1 3 2
D. 4 1 2 3

A) lanthanoids, actinoids

14 elements of 6th period and 14 elements of 7th period in the periodic table are termed as respectively
A. lanthanoids, actinoids
B. actinoids, lanthanoids
C. chalcogens, halogens
D. actinoids, halogens

D) electronegativity

The ability of an atom in a chemical compound to attract shared electron is termed as:
A. electron affinity
B. ionization energy
C. atomic attraction
D. electronegativity

B) 3 4 1 2

Match the Column I (Redox reactions with underlined species) with Column II (Type of change shown by underlined species) and choose the correct option from the codes given below.
Codes: A B C D
A. 2 3 4 1
B. 3 4 1 2
C. 3 4 2 1
D. 3 2 1 4

C) Gay-Lussac’s law

The pressure in well inflated tires of automobiles is almost constant, but on a hot summer day this increases considerably and the tire may burst. This phenomena is explained by
A. Boyle’s law
B. Charles’ law
C. Gay-Lussac’s law
D. Avogadro’s law

A) I and III

Consider the following orders.
I. Gas > Liquid > Solid [Thermal energy]
II. Gas > Liquid > Solid [Intermolecular energy]
III. Solid > Liquid > Gas [Intermolecular energy]
IV. Solid > Liquid > Gas [Thermal energy]
Choose the correct order and select the correct statement.
A. I and III
B. I and II
C. II and IV
D. III and IV

B) III and IV only

What conclusion would you draw from the following graphs?
I. As the temperature is reduced, the volume as well as the pressure increase.
II. As the temperature is reduced, the volume becomes zero and the pressure reaches infinity.
III. As the temperature is reduced, the volume as well as the pressure decrease.
IV. A point is reached where, theoretically, the volume as well as the pressure become zero.
A. I and II only
B. III and IV only
C. II and III only
D. III only
E. AOTA

C) Thermos flask

Which of the following systems is classified as an isolated system?
A. Reactants in an open beaker
B. Hot water kept in closed container
C. Thermos flask
D. Both B and C
E. NOTA

A) Adiabatic process

The process in which system does not exchange heat with its surroundings
A. Adiabatic process
B. Isothermal process
C. Isobaric process
D. Isochoric process

A) q will be negative

In an exothermic reaction, heat is evolved, and the system loses heat to the surrounding. For such system, which of the following is correct?
A. q will be negative
B. H will be zero
C. q will be positive
D. H will be positive

E) AOTA

Which of the following statements is correct?
A. When G = 0, the system is at equilibrium.
B. When G < 0, the process will be spontaneous.
C. When G is negative, the process is said to be exergonic.
D. When G is positive, the process is said to be endergonic.
E. AOTA

D) The reaction is exothermic.

Based on the diagram below, which of the following is true?
A. The activation energy required for the reverse reaction is lower than that for the forward reaction.
B. A catalyst for the reaction is impossible.
C. The reaction is endothermic.
D. The reaction is exothermic.

D) by increasing pressure and decreasing temperature

For the reversible reaction,
N2 (g) + 3H2 (g) ⇌ 2NH3 (g) + heat
The equilibrium shifts in forward direction:
A. by increasing the concentration of NH3
B. by decreasing the pressure
C. by decreasing the concentrations of N2 and H2
D. by increasing pressure and decreasing temperature

C) strong acids have very weak conjugate bases

Strong acid dissociates completely in water, resulting to the formation of a base. Which of the following is correct?
A. strong acids have strong conjugate bases
B. strong acids have strong conjugate acids
C. strong acids have very weak conjugate bases
D. strong acids have very weak conjugate acids

B) H2PO3-

The conjugate acid of the HPO3 2- ion is:
A. PO3 3-
B. H2PO3 -
C. H3PO3
D. H2PO4 -
E. H3PO4

B) PbO2

Which of the following compounds is the most likely to be amphoteric?
A. Li2O
B. PbO2
C. MgO
D. P4O10

C) Gray

Which unit measures radiation absorbed dose?
A. Roentgen
B. Sievert
C. Gray
D. Coulomb per Kg

B) Beta decay

Which of the following radioactive decay processes does not reduce the atomic number of a nuclide?
A. Alpha decay
B. Beta decay
C. Both alpha and beta decay
D. Neither alpha and beta decay

A) 3-keto-2-methylhex-4-enal

The IUPAC name of the compound below:
A. 3-keto-2-methylhex-4-enal
B. 5-formylhex-2-en-3-one
C. 5-methyl-4-oxohex-2-en-5-al
D. 3-keto-2-methylhex-5-enal

C) (Structure C)

The most stable carbocation, among the following is
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

B) Chain isomers

The given structures are:
A. Conformational isomers
B. Chain isomers
C. Position isomers
D. Functional isomers

A) A has a higher boiling point than B

Which of the following statement(s) is correct regarding the following structures?
A. A has a higher boiling point than B
B. A is more stable than B
C. B has a higher dipole moment than A
D. AOTA

B) (Structure B)

The most stable conformation of 1,2-diphenylethane is:
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

C) (Structure C)

Which of the following compounds has the lowest boiling point?
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

B) 1,2-dibromobutane

The main product of the reaction of 1-butene with excess bromine is
A. 1,1-dibromobutane
B. 1,2-dibromobutane
C. 2,2-dibromobutane
D. perbromobutane

D) (Structure D)

The halogenation of paraffins with chlorine proceeds by the free-radical chain mechanism. Among the following, which is the chain-terminating reaction?
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

C) electrophilic substitution reactions

The most common reactions that benzene and its derivatives undergo are
A. electrophilic addition reactions
B. nucleophilic addition reactions
C. electrophilic substitution reactions
D. nucleophilic substitution reactions

C) cis-3-hexene

The reduction of 3-hexyne with H2/Lindlar’s catalyst gives predominantly
A. n-hexane
B. trans-3-hexene
C. cis-3-hexene
D. a mixture of cis- and trans-3-hexene

D) (Structure D)

The increasing order of the acidity of the following carboxylic acids is
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

D) 3 4 2 1

Match the reagents given in Column I with the compounds with functional group detected in Column II
Codes: A B C D
A. 2 4 3 1
B. 4 1 2 3
C. 3 4 1 2
D. 3 4 2 1

C) Lithium aluminum hydride

Name the reagent used in the reaction:
A. Grignard reagent
B. Silver ammoniacal nitrate
C. Lithium aluminum hydride
D. 50% NaOH
E. Chromic acid

D) Benzoyl chloride

The reaction of benzoic acid and thionyl chloride will produce
A. Benzaldehyde
B. p-chlorobenzoic acid
C. Acetophenone
D. Benzoyl chloride
E. Chlorobenzene

B) II < I < III

Arrange the following aromatic amines in increasing order of basic strength.
A. I < II < III
B. II < I < III
C. III < II < I
D. II < III < I

D) Charcoal, lamp-black and coke

Which of the following are amorphous form of carbon?
A. Coke, fullerenes and charcoal
B. Coke, diamond and graphite
C. Graphite, charcoal and lamp-black
D. Charcoal, lamp-black and coke

A) 3 1 2 4

Match the reactions given in Column I with the suitable method given in Column II. Select the correct option from the codes given below.
A. 3 1 2 4
B. 4 3 2 1
C. 4 1 2 3
D. 3 2 4 1

A) Clark’s method

The primary alternative method used to remove temporary hardness of water is (aside from boiling):
A. Clark’s method
B. Ion-exchange method
C. Synthetic resins method
D. Calgon’s method

C) chlorides and sulphates of calcium and magnesium

Permanent hardness of water is due to the presence of
A. bicarbonates of sodium and potassium
B. chlorides and sulphates of sodium and potassium
C. chlorides and sulphates of calcium and magnesium
D. bicarbonates of calcium and magnesium

C) 2 4 1 3

Match Column I with Column II
A. 2 4 3 1
B. 4 2 1 3
C. 2 4 1 3
D. 3 4 2 1

D) Sodium biphosphate

_____________ is used as a urinary acidifier
A. Calcium chloride
B. Diluted HCl
C. Sodium carbonate
D. Sodium biphosphate
E. Potassium acetate

D) Both a and b

Hydrochloric acid is also known as:
A. Spirit of salt
B. Muriatic acid
C. Sal ammoniac
D. Both a and b

A) Sodium bicarbonate

Which one is an example of a systemic antacid?
A. Sodium bicarbonate
B. Magnesium hydroxide
C. Calcium carbonate
D. Magnesium carbonate

C) Sodium aluminum fluoride

Cryolite is:
A. Sodium fluoride
B. Sodium metaphosphate
C. Sodium aluminum fluoride
D. Sodium monofluorophosphate

B) Penicillamine

Treatment for Wilson’s disease
A. Phosphorus
B. Penicillamine
C. Barium sulfate
D. BAL
E. Sodium bicarbonate

D) Sodium bicarbonate

ORS does not have
A. Glucose
B. Sodium citrate
C. Sodium chloride
D. Sodium bicarbonate
E. Potassium chloride

C) Both a and b

Commonly used desensitizing agent(s)
A. Zinc chloride
B. Strontium chloride
C. Both a and b
D. Stannous fluoride
E. Both b and d

D) Hypercalcemia

Which of the following medical conditions is NOT an indication for the therapeutic use of calcium supplements like calcium carbonate?
A. Hypocalcemia
B. Hyperphosphatemia in chronic kidney disease
C. Osteoporosis
D. Hypercalcemia

B) Central nervous system (CNS) depressant and calcium antagonist

Magnesium sulfate has various medical applications depending on its route of administration. When administered parenterally via intravenous (IV) infusion, its mechanism of action is primarily as a:
A. Laxative and osmotic agent
B. Central nervous system (CNS) depressant and calcium antagonist
C. Antacid that neutralizes stomach acid
D. Dietary supplement to treat hypomagnesemia

C) Organic methylmercury compound

The toxicity of mercury largely depends on its chemical form. Which form of mercury is most bioavailable and neurotoxic?
A. Elemental mercury vapor
B. Inorganic mercury salts
C. Organic methylmercury compound
D. Insoluble mercuric sulfide (cinnabar)

C) Hydrogen sulfide

A potential side effect of using bismuth subsalicylate is the harmless darkening of the stools. This effect is caused by the reaction of bismuth with which substance in the colon?
A. Carbon dioxide
B. Ammonia
C. Hydrogen sulfide
D. Intestinal bacteria
E. Hydrochloric acid

C) 2 4 1 3

Match the drug in Column I with chemical composition in Column II
A. 2 4 3 1
B. 4 2 1 3
C. 2 4 1 3
D. 3 4 2 1

B) Zinc oxide

Calamine lotion is a topical agent used to treat minor skin irritations and itching. It primarily contains zinc oxide and ferric oxide. The protective and astringent effects of calamine are primarily due to which component?
A. Ferric oxide
B. Zinc oxide
C. Phenol
D. Zinc carbonate

B) Very low aqueous solubility.

Barium sulfate is a widely used oral contrast agent for gastrointestinal radiography. It is safe for this purpose because of its:
A. High solubility in water and stomach acid.
B. Very low aqueous solubility.
C. Strong oxidizing properties.
D. Ability to be rapidly absorbed and excreted.

C) Rheumatoid arthritis

Gold compounds, particularly gold salts like sodium aurothiomalate, were historically used in the treatment of which condition?
A. Gout
B. Osteoporosis
C. Rheumatoid arthritis
D. Lupus

B) Silver

Which element in Group 1B is the best conductor of electricity?
A. Copper
B. Silver
C. Gold
D. Both silver and gold are equally conductive

A) 3 4 1 2

Match Column I with Column II
A. 3 4 1 2
B. 4 5 1 3
C. 1 4 3 2
D. 2 4 1 5

D) Water vapor

It is considered as the best expectorant:
A. Ammonium chloride
B. Potassium iodide
C. Ammonium carbonate
D. Water vapor

B) Blue

According to NFPA-99 standards, what is the color code for a medical nitrous oxide gas cylinder?
A. Grey
B. Blue
C. Black
D. Brown

D) Aquamarine

Which of the following common names is the other name for Beryl?
A. Amethyst
B. Selenite
C. Gypsum
D. Aquamarine
E. Quartz

A) I, II, III

Which of the following elements are amphoteric?
I. Beryllium
II. Zinc
III. Aluminum
IV. Calcium
A. I, II, III
B. II, III, IV
C. III, IV
D. I, II

C) 2 4 1 3

Match Column I with Column II
A. 3 5 4 2
B. 4 1 5 3
C. 2 4 1 3
D. 1 2 3 4

D) Washed sulfur

Different pharmaceutical forms of elemental sulfur exist. Which elemental form of sulfur is made by treating sublimed sulfur with ammonia to dissolve all impurities and is used internally as a cathartic?
A. Flowers of sulfur
B. Lac or milk sulfur
C. Precipitated sulfur
D. Washed sulfur

B) 6 3 5 1 4

Match the elements/compound in Column I with the method of extraction/manufacturing process in Column II
A. 3 5 4 2 6
B. 6 3 5 1 4
C. 2 4 5 3 6
D. 4 3 2 1 5
E. 6 1 3 5 2

E) 2 5 3 1 4

Match Radiopharmaceuticals in Column I with their Clinical Uses in Column II
A. 3 5 4 1 2
B. 2 3 6 5 4
C. 3 1 5 4 6
D. 2 5 4 1 3
E. 2 5 3 1 4

B) Conjugation with an endogenous substance

Phase II metabolic reactions primarily involve which of the following processes?
A. Oxidation, reduction, and hydrolysis
B. Conjugation with an endogenous substance
C. Cleavage of chemical bonds
D. Formation of an active metabolite

C) Beta-lactam ring

The primary structural feature responsible for the antibacterial activity of beta-lactam antibiotics is the:
A. Thiazolidine ring
B. Acyl side chain
C. Beta-lactam ring
D. Carboxylic acid group

D) All of the above

Modifying the acyl side chain (R group) of penicillin can alter which of the following properties?
A. Spectrum of activity
B. Resistance to beta-lactamases
C. Oral bioavailability
D. All of the above

B) Electron-withdrawing group at the C-6 side chain.

Penicillin V (phenoxymethylpenicillin) is acid-stable and effective for oral administration, unlike Penicillin G (benzylpenicillin), which is acid-labile. This difference is primarily due to the addition of a:
A. Aromatic ring at the C-6 side chain.
B. Electron-withdrawing group at the C-6 side chain.
C. Carboxyl group at position C-3.
D. Methyl group at position C-2.

A) A bulky group at the C-6 side chain.

Methicillin was developed to overcome resistance from staphylococcal penicillinase. This was achieved by adding which structural feature to the penicillin core?
A. A bulky group at the C-6 side chain.
B. A positively charged group at the C-6 side chain.
C. An ester group at the C-3 position.
D. A hydroxyl group at the C-6 side chain.

B) The beta-lactam ring is not fused to a second ring.

Aztreonam is often a suitable alternative for patients with a severe allergy to other beta-lactams, such as penicillins and cephalosporins. The key structural feature that minimizes cross-reactivity is that:
A. It lacks a carboxylic acid group at C-3.
B. The beta-lactam ring is not fused to a second ring.
C. It contains a sulfonate group attached to the ring nitrogen.
D. It has a different stereochemistry than other beta-lactams.

C) Enhanced resistance to beta-lactamases

In cephalosporins, the addition of a methoxy group (OCH3) at position C7 of the beta-lactam ring, as found in cephamycins like cefoxitin, primarily leads to:
A. An expanded spectrum of activity
B. Increased Gram-positive coverage
C. Enhanced resistance to beta-lactamases
D. Improved oral absorption

D) Meropenem

This drugs is structurally similar to the penicillins, but the sulfur atom in position 1 of the structure has been replaced with a carbon atom and an unsaturation is introduced at C2:
A. Aztreonam
B. Cefotetan
C. Piperacillin
D. Meropenem

C) 3 1 4 2

Match the following opioids in Column I with their corresponding opioid subtype classification in Column II
A. 2 1 3 4
B. 4 2 1 3
C. 3 1 4 2
D. 3 4 2 1

C) Substitution on the nitrogen atom with a bulkier group (e.g., allyl or cyclopropylmethyl).

The primary structural modification responsible for converting morphine-like agonists into opioid antagonists (e.g., naloxone) is the:
A. Addition of a methyl group to the C3 phenolic hydroxyl.
B. Conversion of the C6 hydroxyl to a ketone.
C. Substitution on the nitrogen atom with a bulkier group (e.g., allyl or cyclopropylmethyl).
D. Removal of the C14 hydroxyl group.

E) 4 2 3 2 1

Match the following anti-infectives in Column I with their corresponding MOA in Column II
A. 2 1 3 4 3
B. 4 4 3 2 1
C. 4 2 4 2 1
D. 2 2 1 2 1
E. 4 2 3 2 1

A) Ortho and meta positions (forming a catechol)

For maximal activity as a direct-acting adrenergic agonist, the phenyl ethylamine side chain requires a hydroxyl group at which position of the aromatic ring?
A. Ortho and meta positions (forming a catechol)
B. Para position only
C. Meta position only
D. Ortho position only

A) The hydroxymethylene group

The following structure is the anti-asthmatic agent Salbutamol. Which of the following groups is important in conferring greater metabolic stability compared to noradrenaline (norepinephrine)?
A. The hydroxymethylene group
B. The phenol
C. The alcohol
D. The tertiary butyl group

B) Aromatic ring substitution pattern

The primary feature determining the (cardio-selective) or non-selective beta-blocker activity for antagonists like metoprolol and propranolol, respectively, is the:
A. Presence of a hydroxyl group on the carbon
B. Aromatic ring substitution pattern
C. Size of the substituent on the amino nitrogen
D. Presence of a chiral center

C) (Structure C)

Which of the following is a selective β1 receptor agonist?
A. (Structure A)
B. (Structure B)
C. (Structure C)
D. (Structure D)

B) Structure B

Identify carbachol from the following cholinergic modulators:
A. Structure A
B. Structure B
C. Structure C
D. Structure D

C) Metabolism.

The classification of a local anesthetic as an ester or an amide is determined by the intermediate chain. This structural difference primarily impacts the drug’s:
A. Potency.
B. Receptor binding.
C. Metabolism.
D. Both potency and receptor binding

E) 2 5 4 3 1

Match the following drugs in Column I with their corresponding biologic origins in Column II
A. 5 2 3 4 1
B. 2 5 3 4 1
C. 5 2 4 3 1
D. 5 2 1 4 3
E. 2 5 4 3 1

E) Mefenamic acid

Identify the given anti-inflammatory agent.
A. Sulindac
B. Paracetamol
C. Phenacetin
D. Naproxen
E. Mefenamic acid

C) The greater selectivity of tertiary amines for serotonin reuptake inhibition compared to norepinephrine reuptake inhibition.

The difference in pharmacological activity between tertiary amine TCAs (e.g., amitriptyline) and secondary amine TCAs (e.g., nortriptyline) is primarily attributed to:
A. The increased lipid solubility of secondary amines.
B. The longer half-life of tertiary amines.
C. The greater selectivity of tertiary amines for serotonin reuptake inhibition compared to norepinephrine reuptake inhibition.
D. The enhanced binding of secondary amines to histamine receptors.

B) Position 7

Benzodiazepines are characterized by a core chemical structure consisting of a benzene ring fused to a seven-membered diazepine ring. For optimal activity, an electron-withdrawing substituent is generally required at which position of the benzene ring?
A. Position 6
B. Position 7
C. Position 8
D. Position 9

B) They possess a 3-hydroxy group, allowing them to bypass Phase I oxidative metabolism and undergo direct Phase II glucuronidation.

Lorazepam, oxazepam, and temazepam (“LOT” drugs) are often considered safer choices for elderly patients. What structural feature do they share that alters their metabolism?
A. They all lack a C7 halogen.
B. They possess a 3-hydroxy group, allowing them to bypass Phase I oxidative metabolism and undergo direct Phase II glucuronidation.
C. They have an extra fused triazole ring.
D. They are all highly water-soluble prodrugs.

A) Artemether

Endoperoxide 1,2,4-trioxane ring is responsible for the antimalarial action of which drug?
A. Artemether
B. Primaquine
C. Pyrimethamine
D. Quinacrine

B) 4-aminoquinoline

Amodiaquine is a derivative of
A. 2-aminoquinoline
B. 4-aminoquinoline
C. Isoquinoline
D. 4-quinoline methanol
E. 8-aminoquinoline

C) A phenolic A-ring in estrogens.

Which of the following structural characteristics is a key differentiator between the estrogen and androgen core steroid skeletons?
A. The presence of a five-membered D-ring.
B. The presence of a C19 methyl group in androgens.
C. A phenolic A-ring in estrogens.
D. A keto group at C3 in androgens.

C) 5 3 6 1 4

Match the ions/metals in Column I to their characteristic colors to a nonluminous flame in Column II
A. 5 2 3 1 4
B. 2 5 4 3 6
C. 5 3 6 1 4
D. 5 1 4 3 6
E. 2 3 6 1 4

D) Beilstein test

Halogens present in organic compounds may be detected by heating the compound on a copper foil in a Bunsen nonluminous flame whereby it imparts green colour to the flame. This test is known as
A. Marsh’s test
B. Lassaigne’s test
C. Gutzeit test
D. Beilstein test

C) Group V

In which group of systematic cation analysis are cations precipitated as carbonates?
A. Group II
B. Group IV
C. Group V
D. Group VI

A) 4 5 2 3 1

Match the products in Column I to their composition or identity in Column II
A. 4 5 2 3 1
B. 6 1 3 5 4
C. 4 5 2 1 3
D. 6 5 4 1 3
E. 4 5 3 1 6

B) Sb2S3

An orange-red sulfide insoluble in NH3 but soluble in excess (NH4)2S:
A. CdS
B. Sb2S3
C. HgS
D. MnS
E. ZnS