Question 1

Which is the most malleable metal?

Accepted Answer

The correct answer is: Gold. Gold is the most malleable (and ductile) metal. It can be beaten into extremely thin gold sheets (gold leaf) without breaking.

Question 2

What is dry ice?

Accepted Answer

The correct answer is: Solid Carbon dioxide. Dry ice is the common name for solid Carbon Dioxide ($CO_2$). It is used as a cooling agent because it sublimates directly from solid to gas.

Question 3

What is the common name of Calcium Hypochlorite?

Accepted Answer

The correct answer is: Bleaching powder. Calcium Hypochlorite ($Ca(OCl)_2$) is the chemical name for Bleaching Powder, widely used for disinfecting water and bleaching.

Question 4

Food cans are coated with tin instead of zinc due to:

Accepted Answer

The correct answer is: Zinc is more reactive than tin.. Zinc is more reactive than tin. It can react with acids present in food items and make them toxic, whereas tin is less reactive and safe for food contact.

Question 5

Consider the following pairs of elements and their chemical symbols:

- a. Sodium: 3. Na
- b. Carbon: 4. C
- c. Sulphur: 1. S
- d. Cobalt: 2. Co

Which of the following pairs is/are correctly matched?

Accepted Answer

The correct answer is: a-3, b-4, c-1, d-2. The correct symbols are: Sodium (Na) -> a-3, Carbon (C) -> b-4, Sulphur (S) -> c-1, Cobalt (Co) -> d-2.

Question 6

The best material to collect liquid samples of suspected accelerants found at crime scene is

Accepted Answer

The correct answer is: Airtight metal container. Suspected liquid accelerants (hydrocarbons like gasoline) must be collected in airtight metal containers (such as clean paint cans) because hydrocarbons can dissolve plastic and glass can break.

Question 7

Consider the following statements:

i. The sugar molecule in RNA is ribose
ii. The purine bases in RNA are cytosine and uracil
iii. RNA molecule is a single-stranded molecule.

Which of the statements are true?

Accepted Answer

The correct answer is: i and iii only. Statements i (ribose sugar) and iii (single-stranded) are true. Statement ii is false because cytosine and uracil are pyrimidine bases, not purines (which are adenine and guanine).

Question 8

How must the charred or burnt debris that may have absorbed accelerants from the crime scene be packaged?

Accepted Answer

The correct answer is: Airtight containers. Charred debris from suspected arson must be packaged in airtight containers (like metal cans) to prevent volatile accelerant vapors from evaporating.

Question 9

In arson cases, what does "pyromania" mean?

Accepted Answer

The correct answer is: Obsessive and impulsive desire to set things on fire. Pyromania is an obsessive, impulsive disorder characterized by the deliberate and repetitive setting of fires.

Question 10

While investigating an arson crime scene, what can indicate the possible area of origin of the fire?

Accepted Answer

The correct answer is: Area with maximum damage. The area of origin in a fire scene typically exhibits the longest exposure to fire, resulting in the maximum amount of charring and structural damage.

Question 11

Sampling of residue deposited on an item in an explosive scene can be collected by vigorously swabbing the surface with several swabs moistened with which of the following?

Accepted Answer

The correct answer is: Distilled water. Forensic protocols specify using swabs moistened with distilled water (for inorganic residues/salts) or specific solvents like methanol/ethanol for organic explosive residues. In general, distilled water is the standard safe choice.

Question 12

In an immunochromatography assay, what would the control zone comprise of?

Accepted Answer

The correct answer is: Immobilised unlabelled antiglobulin. The control line contains immobilized antiglobulin antibodies (e.g., anti-mouse IgG) that capture excess dye-labeled detection antibodies to show the test ran correctly.

Question 13

Arrange the steps of immunoprecipitation in the right order:

i. Elution
ii. Binding of antigen and antibody
iii. Immobilisation of primary antibody on a matrix

Accepted Answer

The correct answer is: iii, ii, i. The correct sequence for immunoprecipitation is: first immobilizing the antibody on a solid support (iii), then binding the antigen/target (ii), and finally eluting the purified antigen (i).

Question 14

In linear nitrosyl NO acts as a/an:

Accepted Answer

The correct answer is: Three electron donor. In inorganic complexes, a linear M-N-O system is formalistically treated as coordination of a NO+ ligand, which acts as a 3-electron donor to the metal.

Question 15

The order of CO bond strength in the following metal hexacarbonyls is likely to be:

Accepted Answer

The correct answer is: V(CO)_6^- < Cr(CO)_6 < Mn(CO)_6^+. CO bond strength is determined by metal-to-ligand backbonding. More negative charge on the metal increases pi-backdonation, weakening the C-O bond. Thus, V(CO)6^- has the weakest C-O bond, and Mn(CO)6^+ has the strongest C-O bond.

Question 16

Predict the number of Fe-Fe bonds in [(eta^5-C_5H_5)Fe(CO)]_2 molecules using the 18 electron rule:

Accepted Answer

The correct answer is: One. The formula represents the cyclopentadienyl iron dicarbonyl dimer [CpFe(CO)2]2 (with a typo in the exam paper missing the 2 after CO). Under the 18-electron rule, each Fe atom contributes 8e^-, Cp contributes 5e^-, two CO ligands contribute 4e^-, totaling 17e^-. To satisfy the 18-electron rule, there must be exactly 1 Fe-Fe single bond.

Question 17

Solvent extraction is a ______ analytical technique

Accepted Answer

The correct answer is: All A, B and C. Solvent extraction is primarily a separation technique, but it is extensively utilized in qualitative identification and quantitative analysis (hence 'All A, B and C' is selected in standard chemistry answer keys).

Question 18

Reversed phase SPE separates analytes based on their

Accepted Answer

The correct answer is: Polarity. Reversed-phase Solid Phase Extraction (SPE) utilizes a non-polar stationary phase and a polar mobile phase, separating analytes based on differences in their polarities.

Question 19

______ technique involves the use of a fiber coated with an extracting phase, that can be a liquid (polymer) or a solid (sorbent)

Accepted Answer

The correct answer is: Solid phase micro extraction. Solid-Phase Microextraction (SPME) uses a fine fiber coated with a polymer extraction phase to adsorb volatile and semi-volatile analytes directly from headspaces.

Question 20

Accelerated Solvent extraction is useful for EXCEPT

Accepted Answer

The correct answer is: Metals. Accelerated Solvent Extraction (ASE) is a high-temperature, high-pressure organic extraction method suited for organic compounds (pesticides, plasticizers, biodiesel) but is not used for extracting inorganic metals.

Question 21

______ is based on the working principle of acoustic cavitation

Accepted Answer

The correct answer is: Ultrasonic extraction. Ultrasonic-assisted extraction (UAE) utilizes high-frequency sound waves to create microbubbles in the solvent. The implosion of these bubbles (acoustic cavitation) ruptures cell walls to release target analytes.

Question 22

Example for Zwitterions is

Accepted Answer

The correct answer is: Glycine. Glycine is an amino acid that exists as a zwitterion (containing both a positive ammonium charge and a negative carboxylate charge) at neutral pH.

Question 23

Acetic acid in liquid ammonia behaves as

Accepted Answer

The correct answer is: Stronger acid than that in water. Liquid ammonia is a basic solvent. It exerts a levelling effect on acids, making even weak acids like acetic acid behave as strong acids (fully deprotonated) compared to water.

Question 24

Which of the following species has the highest electronegativity?

Accepted Answer

The correct answer is: N (sp hybridized). Electronegativity increases with increasing s-character of the hybrid orbital. Nitrogen is naturally more electronegative than Carbon, and sp-hybridized Nitrogen (50% s-character) has the highest electronegativity among the choices.

Question 25

The reaction of BCl_3 with NH_4Cl gives product A which upon reduction by NaBH_4 gives product B. Product B upon reacting with HCl affords compound C, which is

Accepted Answer

The correct answer is: Cl_3B_3N_3H_9. The reaction of BCl3 with NH4Cl yields trichloroborazine [ClBNH]3 (Product A). Reduction with NaBH4 gives borazine B3N3H6 (Product B). Borazine reacts with HCl in an addition reaction across the polar B-N bonds to yield B-trichloroborazine trihydrochloride Cl3B3N3H9 (Compound C).

Question 26

What type of crime scene does arson signify?

Accepted Answer

The correct answer is: Unlawful destruction of property or a person by fire. Arson is the criminal act of deliberately and unlawfully setting fire to property, structures, or wildland areas.

Question 27

Which is not a component of a kit required for lifting footprint from a crime scene?

Accepted Answer

The correct answer is: FTK card. FTK (Flinders Technology Key) card is used for collecting and preserving DNA samples, not footprints. Plaster of Paris, tape, and oblique lighting are standard footprint recovery materials.

Question 28

What type of evidence may fluoresce under an alternate light source?

Accepted Answer

The correct answer is: Semen, blood, saliva. Semen and saliva contain biological substances (proteins/urea) that fluoresce strongly under UV/alternate light sources. Blood does not fluoresce directly but absorbs light (looks dark/black), but in many standard exam keys, semen, blood, and saliva are listed together as fluid traces detected by ALS.

Question 29

What section defines the term "Admissibility"?

Accepted Answer

The correct answer is: Section-45, India Evidence Act. Section 45 of the Indian Evidence Act defines the relevancy and admissibility of expert opinions (opinions of experts on foreign law, science, art, identity, handwriting, or finger impressions).

Question 30

What does the term cross-examination mean?

Accepted Answer

The correct answer is: Examination of witness by the opposite party. Under Section 137 of the Indian Evidence Act, the examination of a witness by the adverse (opposite) party is called cross-examination.

Question 31

'Affeem' is the common name for what narcotic substance.

Accepted Answer

The correct answer is: Opium. 'Afeem' (or Afeem) is the common Hindi/Urdu term for Opium, which is derived from the latex of the Papaver somniferum poppy.

Question 32

What is not a phenanthrene alkaloid extracted from Opium plant?

Accepted Answer

The correct answer is: Narcotine. Opium alkaloids include phenanthrenes (morphine, codeine, thebaine) and benzylisoquinolines (narcotine/noscapine, papaverine). Thus, Narcotine is not a phenanthrene alkaloid.

Question 33

Cocaine is extracted from plant belonging to family

Accepted Answer

The correct answer is: Erythroxylum. Cocaine is extracted from the leaves of the Erythroxylum coca plant (family Erythroxylaceae). Erythroxylum is the genus name representing this botanical source.

Question 34

Which is not true for Morphine?

Accepted Answer

The correct answer is: Metabolises into 6 MAM on metabolism. Heroin metabolizes into 6-monoacetylmorphine (6-MAM), and then into morphine. Morphine does not metabolize into 6-MAM; it metabolizes into glucuronides (M3G, M6G).

Question 35

What is an example of synthetic cannabinoid?

Accepted Answer

The correct answer is: Spice. Spice (or K2) is a common street name for herbal mixtures sprayed with synthetic cannabinoids.

Question 36

What is the chemical name of ecstasy?

Accepted Answer

The correct answer is: MDMA. Ecstasy is the street name for MDMA (3,4-Methylenedioxymethamphetamine), a synthetic psychoactive drug.

Question 37

What controlled substance can be used to synthesize heroin from morphine?

Accepted Answer

The correct answer is: Acetic anhydride. Acetic anhydride is a key precursor chemical used to acetylate morphine into heroin (diacetylmorphine). It is highly controlled internationally.

Question 38

What is an example of synthetic drug?

Accepted Answer

The correct answer is: Barbiturate. Barbiturates (like phenobarbital) are fully synthetic sedative-hypnotic drugs. Codeine, Cocaine, and Cathinone are natural alkaloids or derived from plants.

Question 39

Composition of triple base powders include

Accepted Answer

The correct answer is: One part Nitrocellulose + One part Nitroglycerine + One part Nitroguanidine. Triple-base smokeless gunpowders consist of three main energetic materials: nitrocellulose, nitroglycerin, and nitroguanidine.

Question 40

Griess test with Zinc dust is used for the detection of

Accepted Answer

The correct answer is: Nitrates. The Griess reagent directly detects nitrites. Adding Zinc dust reduces nitrates to nitrites, allowing the Griess test to detect Nitrates (such as residues from gunpowder).

Question 41

What is the best solvent to extract secondary high explosives?

Accepted Answer

The correct answer is: Acetone. Acetone is the most commonly used organic solvent to dissolve and extract secondary high explosives (like RDX, TNT, PETN, and HMX) from post-blast debris.

Question 42

What is not the primary component of an high explosive train?

Accepted Answer

The correct answer is: Safety Switch. An explosive train consists of a fuse, primer (detonator), booster, and main charge. A safety switch is an electrical or mechanical safety device, not an active chemical/explosive component of the train itself.

Question 43

"Booby trap" type of TED is designed to function when

Accepted Answer

The correct answer is: Victim does something to initiate the initiation mechanism. A booby trap is an explosive device (IED) designed to be triggered unknowingly by the victim performing a specific, routine action (like opening a door or lifting an object).

Question 44

Deflagrating explosives have method of initiation as

Accepted Answer

The correct answer is: Ignition. Low/deflagrating explosives (like black powder or smokeless powder) burn rapidly and are initiated by simple ignition or flame, as opposed to high explosives which require a shockwave (detonation) to initiate.

Question 45

What are the fundamental features of an explosive?

Accepted Answer

The correct answer is: Formation of gaseous by-products with simultaneous release of energy. The absolute defining chemical features of an explosion are the rapid conversion of a solid or liquid into gaseous products with a simultaneous massive release of heat and pressure energy.

Question 46

What is the composition of C4 explosive?

Accepted Answer

The correct answer is: 91% RDX, 9% Plastizer. Composition C4 is a plastic explosive composed of about 91% RDX (explosive) and 9% plasticizer (such as dioctyl sebacate or polyisobutylene binding agent).

Question 47

Roussin's Test is used to identify' alkaloid of

Accepted Answer

The correct answer is: Nicotine. Roussin's crystals test (yielding characteristic crystalline forms under microscopic view) is a microchemical test specifically used to identify nicotine.

Question 48

Ehrlich reagent used for presumptive detection of LSD contains

Accepted Answer

The correct answer is: p-dimethylaminobenzaldehyde. Ehrlich's reagent consists of p-dimethylaminobenzaldehyde (DMAB) in ethanol and hydrochloric acid. It turns purple in the presence of LSD.

Question 49

What alkaloid shows appearance of golden yellow needle with gold chloride and hydrochloric acid?

Accepted Answer

The correct answer is: Aconite. Aconitine (the active alkaloid of Aconitum or Aconite) yields characteristic golden-yellow needles or crystalline rosettes when reacted with gold chloride in hydrochloric acid.

Question 50

What is an example of stupefying agent used for committing crimes?

Accepted Answer

The correct answer is: Nitrazepam. Benzodiazepines like Nitrazepam (or Lorazepam/Diazepam) are common stupefying or sleep-inducing agents slipped into drinks to facilitate crimes (drug-facilitated crimes).

Question 51

Urine testing kit for the exposure to drugs is based on principle of

Accepted Answer

The correct answer is: Immunoassay. Commercial rapid urine drug test kits utilize lateral flow immunochromatographic assays (Immunoassays) to detect drugs or their metabolites.

Question 52

Fisher Morris test for Heroin shows what colour in chloroform layer

Accepted Answer

The correct answer is: Yellow. The Fisher-Morris test is a color test used to differentiate heroin from morphine. Heroin yields a faint blue color in the aqueous layer and a yellow color in the chloroform layer.

Question 53

What is the common name for petroleum oil?

Accepted Answer

The correct answer is: Black Gold. Petroleum (crude oil) is commonly referred to as 'Black Gold' due to its dark appearance when extracted and its high economic value.

Question 54

Blue colour in PDS supplied kerosene is due to

Accepted Answer

The correct answer is: Dialkyl amino anthraquinone. Public Distribution System (PDS) kerosene in India is dyed blue using a synthetic organic dye, typically dialkylaminoanthraquinone (often known as solvent blue dye).

Question 55

What is not the component of a commercial motor gasoline?

Accepted Answer

The correct answer is: Neoalkanes. Motor gasoline consists primarily of hydrocarbons belonging to paraffins (alkanes), olefins (alkenes), naphthenes (cycloalkanes), and aromatics. Neoalkanes is not classified as a distinct bulk component group in petroleum fuel analysis.

Question 56

Kerosene is composed of carbon chains ranging typically between

Accepted Answer

The correct answer is: C_10-C_16. Kerosene is a middle distillate fraction of petroleum, composed of hydrocarbons containing carbon numbers typically between C10 and C16.

Question 57

Tetraethyl lead is added to gasoline to serve as

Accepted Answer

The correct answer is: Anti-knocking agent. Tetraethyl lead (TEL) was historically added to gasoline as an anti-knocking agent to increase the fuel's octane rating and prevent engine knocking.

Question 58

What type of coal has the lowest content of carbon?

Accepted Answer

The correct answer is: Lignite. Lignite (often called brown coal) has the lowest carbon content (about 25-35%), whereas Anthracite has the highest carbon content (86-97%).

Question 59

What process is used in industry to separate various components of crude oil?

Accepted Answer

The correct answer is: Fractional Distillation. Fractional distillation separates crude oil into fractions of different boiling points, such as petrol, diesel, kerosene, and heavy oils, in a fractionating column.

Question 60

Adulteration of motor gasoline with kerosene oil can be detected by

Accepted Answer

The correct answer is: Gas Liquid Chromatography. Gas-Liquid Chromatography (GLC) is the gold standard method to analyze fuel profiles and detect adulteration of gasoline with heavier kerosene fractions by resolving hydrocarbon peaks.

Question 61

Debris collected from the arson crime scene should be collected in

Accepted Answer

The correct answer is: Metal box with lid. Arson debris must be collected in an airtight container, such as a clean metal box/can with a tight lid, to prevent volatile accelerant vapors (like gasoline) from escaping.

Question 62

Which of the following apparatus can be used to estimate flashpoint?

Accepted Answer

The correct answer is: All of the above. All these instruments (Cleveland Open Cup, Abel Apparatus, and Pensky-Martens Closed Cup) are standard laboratory equipment used to determine the flash point of petroleum products.

Question 63

What is the lowest temperature at which the volatile liquid will burn and continue to without the help of any external source?

Accepted Answer

The correct answer is: Fire Point. The Fire Point is the lowest temperature at which a liquid fuel produces enough vapor to continue burning for at least 5 seconds after ignition by a pilot flame.

Question 64

What pattern of fire at the point of origin indicates unnatural fire?

Accepted Answer

The correct answer is: A shape. An 'inverted V' pattern, which resembles a capital letter 'A' (A shape), often indicates a localized pour of liquid accelerant at the point of origin, characteristic of arson.

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