Assertion (A): Animal skins are colloidal in nature.
Reason (R): Animal skin has positively charged particles.
1
Both (A) and (R) are correct and (R) is the correct explanation of (A)
2
Both (A) and (R) are correct but (R) is not the correct explanation of (A)
3
A is correct but R is incorrect
4
A is incorrect but R is correct
Official Solution
Correct Option: (2)
Animal skin is colloidal in nature due to protein content and fibrous structure.
It does have positive charge, but that is not the sole reason for colloidal nature.
Hence, both statements are correct, but (R) is not the true reason for (A).
02
PYQ 2022
medium
chemistryID: ap-eapce
1.8 g of glucose (molar mass 180 g/mol) is dissolved in 0.1 kg of water. The freezing point of the solution (in °C) is (K for water = 1.86 K kg mol )
1
-0.186
2
-0.372
3
-0.744
4
-0.372
Official Solution
Correct Option: (2)
03
PYQ 2022
medium
chemistryID: ap-eapce
Photographic plates are prepared by coating emulsion of which of the following in gelatin?
1
AgBr
2
CuBr
3
ZnBr
4
FeBr
Official Solution
Correct Option: (1)
Photographic films use silver halide crystals (mostly AgBr) dispersed in gelatin. These crystals are light-sensitive and undergo photochemical reactions when exposed.
04
PYQ 2022
medium
chemistryID: ap-eapce
Curdling of milk is caused due to the formation of which of the following acids by bacteria?
1
Formic acid
2
Acetic acid
3
Lactic acid
4
Maleic acid
Official Solution
Correct Option: (3)
Bacteria such as Lactobacillus ferment lactose (milk sugar) to lactic acid. This acid lowers the pH and causes the milk proteins (mainly casein) to coagulate, resulting in curdling.
05
PYQ 2023
medium
chemistryID: ap-eapce
Which of the following macromolecules is crucial to the communication system in the body?
1
Receptors
2
Enzymes
3
Carrier proteins
4
Lipids
Official Solution
Correct Option: (1)
- Receptors are proteins that are essential for communication between cells in the body. They receive signals (e.g., hormones, neurotransmitters) from the outside and transmit them inside the cell to induce a response.
- Enzymes are involved in metabolic reactions but are not directly involved in cellular communication.
- Carrier proteins are important for transporting substances across membranes but don't directly participate in cellular communication.
- Lipids are important for membrane structure but not directly involved in cellular communication. Thus, the correct answer is (1) Receptors.
06
PYQ 2023
medium
chemistryID: ap-eapce
Given below are two statements: Assertion (A): Hydrolysis of DNA does not form equal numbers of adenine (A) and thymine (T), or guanine (G) and cytosine (C). Reason (R): In DNA, adenine forms hydrogen bonds with thymine and cytosine forms hydrogen bonds with guanine. The correct answer is:
1
Both A and R are correct and R is the correct explanation of A
2
Both A and R are correct but R is not the correct explanation of A
3
A is correct but R is incorrect
4
A is incorrect but R is correct
Official Solution
Correct Option: (4)
- Evaluation of Assertion (A): DNA hydrolysis produces equal amounts of A and T, and G and C. Thus, A is incorrect.
- Evaluation of Reason (R): The statement about base pairing is accurate. Thus, R is correct.
- Relationship between A and R: R correctly describes base pairing but does not explain A. Thus, the correct choice is (4).
07
PYQ 2023
medium
chemistryID: ap-eapce
DDT is
1
A chlorinated organic herbicide.
2
A brominated organic rodenticide.
3
A chlorinated organic insecticide.
4
A brominated organic avicide.
Official Solution
Correct Option: (3)
DDT (Dichlorodiphenyltrichloroethane) is an organochlorine compound that is commonly used as an insecticide. It was widely used during the mid-20th century to control pests in agriculture and in the treatment of malaria.
08
PYQ 2023
medium
chemistryID: ap-eapce
Which of the following drug is used on diseased skin surface?
1
Salvarsan
2
Tetracyclin
3
Furacin
4
Ampicillin
Official Solution
Correct Option: (3)
Furacin (Nitrofurazone) is a topical antibiotic used directly on skin wounds and diseased surfaces.
- Salvarsan is used for syphilis and is not applied topically.
- Tetracycline and ampicillin are systemic antibiotics, taken orally or injected.
09
PYQ 2023
medium
chemistryID: ap-eapce
The number of products obtained in the following reaction is:Reaction:
1
1
2
3
3
2
4
4
Official Solution
Correct Option: (3)
The given reaction involves the base-catalyzed (NaOH) decomposition of 1-phenylethanol (Ph-CH(OH)-CH ) under heating ( ). This leads to two main products through different pathways: Product 1: Acetophenone (Ph-CO-CH ) - Formed via oxidation of the alcohol - The base abstracts a proton from the -OH group - Resulting in formation of a carbonyl group Product 2: Styrene (Ph-CH=CH ) - Formed via elimination reaction - NaOH abstracts a proton from the β-carbon - Leads to formation of a double bond Mechanistic pathways: 1. Oxidation pathway:
2. Elimination pathway:
Why not other options? - Only these two major products form under these conditions - No significant side products are expected - The reaction doesn't proceed to complete decomposition
10
PYQ 2023
medium
chemistryID: ap-eapce
Food preservative sodium benzoate is eliminated from the body as which of the following metabolite?
1
benzamide
2
phenyl acetic acid
3
benzoic acid
4
Hippuric acid
Official Solution
Correct Option: (4)
Sodium benzoate is a common food preservative. When ingested, it is rapidly absorbed and then metabolized in the liver. The primary metabolic pathway for benzoic acid (which is the active form after sodium benzoate is ingested and protonated in the acidic environment of the stomach) involves conjugation with glycine. This conjugation reaction is catalyzed by the enzyme glycine N-acyltransferase and results in the formation of **hippuric acid** (N-benzoyl glycine). Hippuric acid is then readily excreted in the urine. The other options are not the primary metabolites of benzoic acid elimination:
- **Benzamide:** Benzoic acid can be converted to benzamide, but this is not the major elimination pathway in humans.
- **Phenyl acetic acid:** This compound is related to other metabolic pathways in the body, not directly to benzoic acid elimination from sodium benzoate.
- **Benzoic acid:** While some benzoic acid might be excreted unchanged, the major pathway involves its conversion to hippuric acid. Therefore, sodium benzoate is eliminated from the body primarily as hippuric acid.
11
PYQ 2023
medium
chemistryID: ap-eapce
In which of the following, drug class is correctly matched with the criteria of drug classification?
1
Analgesics ----- molecular targets
2
Sulphonamides ----- drug action
3
Antihistamines ----- chemical structure
4
Antiseptics ----- pharmacological effect
Official Solution
Correct Option: (4)
To determine which drug class is correctly matched with the criteria of drug classification, we examine the provided options:
Analgesics ----- molecular targets: Analgesics are primarily classified by their effect in relieving pain rather than specific molecular targets. Therefore, this classification does not accurately match.
Sulphonamides ----- drug action: Sulphonamides, which are antimicrobial agents, are typically classified by their mechanism of action, not just their action, making this a partial mismatch.
Antihistamines ----- chemical structure: Antihistamines are grouped by their ability to block histamine at its receptors rather than simply by their chemical structure. Thus, this is not the correct classification criterion.
Antiseptics ----- pharmacological effect: Antiseptics are substances that inhibit the growth and development of microorganisms on living tissues, classified based on their pharmacological effect. This classification is correct.
Based on the analysis above, the correct answer is:
Antiseptics ----- pharmacological effect
12
PYQ 2024
medium
chemistryID: ap-eapce
Which of the following pair is not correctly matched?
1
Salvarsan – to treat syphilis
2
Luminal – Antidepressant
3
Morphine – to treat cardiac pain
4
Acetylsalicylic acid – Antipyretic
Official Solution
Correct Option: (2)
Step 1: Understanding the given drugs and their correct uses - Salvarsan: - Correctly matched. - Used to treat syphilis, an infectious disease caused by the bacterium Treponema pallidum. - Luminal: - Incorrectly matched. - Luminal (Phenobarbital) is a barbiturate drug used as an antiepileptic (to control seizures), not as an antidepressant. - It acts as a central nervous system (CNS) depressant and is commonly prescribed for epilepsy and insomnia. - Morphine: - Correctly matched. - Used as a strong analgesic (pain reliever), particularly for severe pain management, including pain relief in cancer patients and post-surgical recovery. - However, it is not used for treating cardiac pain specifically, but for pain relief in general. - Acetylsalicylic acid (Aspirin): - Correctly matched. - Used as an antipyretic (fever-reducing) and anti-inflammatory drug. - It also has mild analgesic properties and is widely used to prevent blood clot formation in cardiovascular diseases. Step 2: Conclusion Since Luminal is incorrectly matched as an antidepressant (instead, it is used as an anticonvulsant for epilepsy), the correct answer is Option (2).
13
PYQ 2024
easy
chemistryID: ap-eapce
Match the following:
1
2
3
4
Official Solution
Correct Option: (4)
Solution:
The given problem is to match elements to their corresponding categories correctly based on the provided options. We need to identify the suitable pairs from:
Based on the information provided, the correct match is . This indicates that:
The element or compound labeled as A corresponds to category II.
The element or compound labeled as B corresponds to category III.
The element or compound labeled as C corresponds to category I.
To validate the solution, closely examine the properties or specifics of each element, ensuring logical matching to each numbered category in accordance with standard chemical classifications or characteristics.
14
PYQ 2024
easy
chemistryID: ap-eapce
Which of the following reactions give phosphine? i. Reaction of calcium phosphide with water ii. Heating white phosphorus with concentrated NaOH solution in an inert atmosphere iii. Heating red phosphorus with alkali
1
2
3
4
Official Solution
Correct Option: (1)
The reactions that result in the formation of phosphine (PH3) are analyzed below:
Reaction of calcium phosphide (Ca3P2) with water: This reaction yields phosphine and calcium hydroxide:
Thus, option (i) produces phosphine.
Heating white phosphorus (P4) with concentrated NaOH solution in an inert atmosphere: This reaction generates phosphine:
Therefore, option (ii) also leads to phosphine formation.
Heating red phosphorus with alkali: This reaction does not produce phosphine under normal conditions; instead, phosphite salts may form. Hence, option (iii) does not give phosphine.
From the options analyzed, the reactions that give phosphine are i and ii only.
The correct answer is:
15
PYQ 2024
medium
chemistryID: ap-eapce
Identify the correctly matched pair from the following:
1
2
3
Salt of propanoic acid – Antioxidant
4
Veronal – Analgesic
Official Solution
Correct Option: (2)
Step 1: Understanding Chemical Compounds
- The given structure corresponds to sodium benzoate, which is a well-known food preservative. Step 2: Checking Other Options
- The first structure is not an antibiotic; antibiotics are typically complex organic molecules.
- Propanoic acid salts (such as sodium propionate) are used as food preservatives, not antioxidants.
- Veronal is a barbiturate sedative, not an analgesic. Thus, the correct answer is the food preservative. \bigskip
16
PYQ 2025
medium
chemistryID: ap-eapce
Identify the artificial sweetener which has highest sweetness value compared to cane sugar
1
Alitame
2
Aspartame
3
Saccharin
4
Sucralose
Official Solution
Correct Option: (1)
Alitame is a potent artificial sweetener with sweetness nearly 2000 times that of cane sugar. It surpasses other common sweeteners like Aspartame, Saccharin, and Sucralose.
17
PYQ 2025
medium
chemistryID: ap-eapce
Which of the following is not an antibiotic?
1
Chloramphenicol
2
Ofloxacin
3
Penicillin
4
Novestrol
Official Solution
Correct Option: (4)
Novestrol is a hormone and not an antibiotic. Chloramphenicol, Ofloxacin, and Penicillin are antibiotics used to treat bacterial infections.
18
PYQ 2025
medium
chemistryID: ap-eapce
What is the drug used to control depression and hypertension?
1
Bithionol
2
Equanil
3
Dimetapp
4
Prontosil
Official Solution
Correct Option: (2)
Equanil is a tranquilizer that is used to treat stress, anxiety, depression, and mild hypertension.
Bithionol is an anti-helminthic, Dimetapp is an anti-allergic, and Prontosil is an antibacterial sulpha drug.
19
PYQ 2025
medium
chemistryID: ap-eapce
The synthetic detergents of the following are
1
A, B, C only
2
B, C, D only
3
A, D only
4
B, C only
Official Solution
Correct Option: (1)
Synthetic detergents are cleansing agents that have a soap-like action but are not soaps (salts of fatty acids). They typically have a long hydrophobic hydrocarbon tail and a hydrophilic head group. They are classified as anionic, cationic, or non-ionic. A) This is a non-ionic detergent. The long hydrocarbon chain ( -Ph-) provides the hydrophobic part. The polyoxyethylene chain (-\text{O}(\text{CH}_2\text{CH}_2\text{O})_6\text{CH}_2\text{CH}_2\text{OH}\) ) provides the hydrophilic part due to ether linkages and the terminal -OH group capable of hydrogen bonding. Example: detergents formed by reaction of polyethylene glycol with alkylphenols. This is a synthetic detergent. B) (Sodium lauryl sulfate or sodium dodecyl sulfate, SDS) This is an anionic detergent. The is the hydrophobic tail. The is the hydrophilic head group (sulfate group). This is a common synthetic detergent. C) (Cetyltrimethylammonium bromide, CTAB) This is a cationic detergent. The is the hydrophobic tail. The is the quaternary ammonium hydrophilic head group. This is a synthetic detergent. D) (Glyceryl tripalmitate, a triglyceride) This is a fat or oil (specifically, tripalmitin). Fats and oils are triglycerides, which are esters of glycerol and fatty acids. Soaps are made by saponification (hydrolysis with alkali) of fats/oils. This compound itself is a fat, not a detergent. Therefore, A, B, and C are synthetic detergents.
This matches option (1).
20
PYQ 2025
medium
chemistryID: ap-eapce
The artificial sweetener X contains glycosidic linkage and Y contains amide and ester linkages. X and Y respectively are
1
Sucralose, Alitame
2
Sucralose, Aspartame
3
Saccharin, Alitame
4
Saccharin, Aspartame
Official Solution
Correct Option: (2)
Sucralose: A modified sugar molecule containing glycosidic linkages. Aspartame: A dipeptide containing an amide and ester linkage. Saccharin: Does not contain glycosidic linkages. It is a cyclic imide derivative. Alitame: Contains amide and ester linkages, but the question specifies that X must contain the glycosidic linkage.
21
PYQ 2025
medium
chemistryID: ap-eapce
What are X and Y respectively in the following sets of reactions? (major product)
1
2
3
4
Official Solution
Correct Option: (3)
Step 1: The reaction of with gives — a substitution reaction replacing –OH with –Br. Step 2: The reaction of propene ( ) with HBr in the presence of benzoyl peroxide ( ) proceeds via anti-Markovnikov addition due to free radical mechanism, yielding as major product. Step 3: So, X is and Y is , which corresponds to option (3).
22
PYQ 2025
medium
chemistryID: ap-eapce
Match the following polymers with their applications:
Step 1: Understanding Drug Applications - Equanil is used to control hypertension and anxiety disorders. - Furacine is an antiseptic used for treating wounds and burns. - Tegamet (Cimetidine) is an antacid used in treating ulcers and acid reflux. - Veronal (Barbiturate) is a hypnotic drug used for sleep disorders. Conclusion Thus, the correct answer is:
23
PYQ 2025
medium
chemistryID: ap-eapce
Match the following polymers with their applications:
Step 1: Understanding Drug Applications - Equanil is used to control hypertension and anxiety disorders. - Furacine is an antiseptic used for treating wounds and burns. - Tegamet (Cimetidine) is an antacid used in treating ulcers and acid reflux. - Veronal (Barbiturate) is a hypnotic drug used for sleep disorders. Conclusion Thus, the correct answer is:
24
PYQ 2025
medium
chemistryID: ap-eapce
Which of the following is not an example of an antacid?
1
Cimetidine
2
Ranitidine
3
Sodium hydrogen carbonate
4
Phenelzine
Official Solution
Correct Option: (4)
Phenelzine is an antidepressant and monoamine oxidase inhibitor (MAOI), not used as an antacid. The others are commonly used to treat acidity.
25
PYQ 2025
medium
chemistryID: ap-eapce
Which of the following is a synthetic progesterone ?
1
Norethindrone
2
Novestrol
3
Estradiol
4
Testosterone
Official Solution
Correct Option: (1)
Step 1: Understand what synthetic progesterone is.
Progesterone is a naturally occurring steroid hormone that plays a crucial role in the menstrual cycle, pregnancy, and embryogenesis. Synthetic progesterones are compounds designed to mimic the effects of natural progesterone and are often used in birth control pills, hormone replacement therapy, and other medical treatments. They are also known as progestins. Step 2: Analyze each option. \begin{itemize} \item (1) Norethindrone: Norethindrone (also known as norethisterone) is a synthetic progestin. It is widely used in oral contraceptives and for treating gynecological disorders. It is a derivative of testosterone but acts as a progestin. \item (2) Novestrol: This name does not correspond to a commonly known or established synthetic progesterone or any major hormone. It might be a misspelling or an unfamiliar term in this context. Assuming it's a distractor. \item (3) Estradiol: Estradiol is a natural estrogen, the primary female sex hormone. It is not a progesterone or a synthetic progesterone. \item (4) Testosterone: Testosterone is the primary male sex hormone (androgen). It is not a progesterone.
\end{itemize} Step 3: Identify the synthetic progesterone.
Based on the analysis, Norethindrone is a well-known synthetic progesterone (progestin).
26
PYQ 2025
medium
chemistryID: ap-eapce
Identify the incorrect statement regarding artificial sweeteners.
1
Saccharin is the first popular artificial sweetener
2
Aspartame is stable at cooking temperature
3
Among the artificial sweeteners, alitame is a high potency sweetener
4
Sucralose is a trichloro derivative of sucrose
Official Solution
Correct Option: (2)
Aspartame is a low-calorie artificial sweetener but is not heat-stable. It breaks down at high temperatures, making it unsuitable for cooking or baking. In contrast, sweeteners like sucralose and saccharin are heat-stable and used in baked goods. \begin{itemize} \item (1) Correct — Saccharin was the first widely used artificial sweetener. \item (2) Incorrect — Aspartame is not stable at cooking temperatures. \item (3) Correct — Alitame is indeed a high-potency sweetener. \item (4) Correct — Sucralose is a chlorinated derivative of sucrose.
\end{itemize}
