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Organic Chemistry Test

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Among the following polymers, ---------------------- is primary used in the packaging industry.

  1. polyethylene

  2. polypropylene

  3. polystyrene

  4. polyvinyl chloride


Correct Option: A
Explanation:

Polyethylene is the most widely used plastic, with an annual production of approximately 80 million metric tons. Its primary use is in packaging (plastic bag, plastic films, geomembranes, etc.).

The polymer used in automotive and aerospace applications is

  1. polyether ether ketone

  2. polyamide-imides

  3. polyphenylsulfone

  4. polysulfone


Correct Option: C
Explanation:

Polyphenylsulfone is a type of moldable plastic often used in rapid prototyping and rapid manufacturing applications. It is a heat and chemical resistant material. It is typically used in automotive and aerospace applications. It has virtually no melting point due to its amorphous nature.

Which of the following processes involves the polymerization of vinyl monomers with strong electronegative groups?

  1. Free radical polymerization

  2. Cationic polymerization

  3. Anionic addition polymerization

  4. Coordination polymerization


Correct Option: C
Explanation:

Anionic addition polymerization is a form of chain-growth polymerization or addition polymerization that involves the polymerization of vinyl monomers with strong electronegative groups. This polymerization is carried out through a carbanion active species.

The reactants and the catalysts appear in the same phase in

  1. Heterogeneous catalysts

  2. Homogeneous catalysts

  3. Electrocatalyst

  4. Organic catalysts


Correct Option: B
Explanation:

Homogeneous catalysts function in the same phase as the reactants, but the mechanistic principles invoked in heterogeneous catalysis are generally applicable. Typically homogeneous catalysts are dissolved in a solvent with the substrates. One example of homogeneous catalysis involves the influence of H+ on the esterification of esters, e.g. ,methyl acetate from acetic acid and methanol.

In which of the following reactions, trityl hydroxylamine Ar3CNHOH rearranges into triaryl imine ?

  1. The Stieglitz rearrangement

  2. The Schmidt reaction

  3. The Hoesch reaction

  4. The Asinger-reaction


Correct Option: A
Explanation:

The Stieglitz rearrangement is a rearrangement reaction of a trityl hydroxylamine in to a triaryl imine . The reaction is related to the Beckmann rearrangement as both reactions involve a carbon to nitrogen shift.

Which of the following processes acts as a trigger for one or more secondary reactions?

  1. A condensation reaction

  2. Chain initiation

  3. Chain propagation

  4. Chain termination


Correct Option: B
Explanation:

In chemistry, initiation is a chemical reaction that triggers one or more secondary reactions. Often the initiation reaction generates a reactive intermediate from a stable molecule which is then involved in secondary reactions. In polymerisation, initiation is followed by a chain reaction and termination.

Directions: The following question has four choices out of which ONLY ONE is correct.

Fructose is a monosaccharide (simple sugar), which the body can use for energy. The fructose-derived catalyst is used in _______ reaction.

  1. the Diels-Alder reaction

  2. the Michael reaction

  3. the Mannich reaction

  4. the Shi epoxidation


Correct Option: D
Explanation:

The Shi epoxidation is a chemical reaction described as an asymmetric epoxidation of olefins with oxone (potassium peroxymonosulfate) and a fructose-derived catalyst.

Hydronic systems cost-effective radiant heating systems for heating-dominated climates. Which of the following polymers is used in hydronic radiant heating systems?

  1. Liquid-crystal polymers

  2. Polyphthalamide

  3. Cross-linked polyethylene

  4. Polyvinylidene chloride


Correct Option: C
Explanation:

Cross-linked polyethylene is a form of polyethylene with cross-links. It is formed into tubing and is used predominantly in hydronic radiant heating systems, domestic water piping and insulation for high tension (high voltage) electrical cables. It is also used for natural gas and offshore oil applications, chemical transportation, and transportation of sewage and slurries.

Faeces is the waste product discharged from the intestines through the anus. Which of the the organic compounds occurs naturally in faeces ?

  1. Indometacin

  2. Indigo

  3. Oxindole

  4. Skatole


Correct Option: D
Explanation:

Skatole or 3-methylindole is a mildly toxic white crystalline organic compound belonging to the indole family. It occurs naturally in faeces (it is produced from tryptophan in the mammalian digestive tract), and coal tar, and has a strong faecal odour.

In which of the following reactions, primary or secondary amine is methylated using excess formic acid and formaldehyde?

  1. The Aza Diels-Alder reaction

  2. The Baylis-Hillman reaction

  3. The Eschweiler-Clarke reaction

  4. The Amadori Rearrangement


Correct Option: C
Explanation:

The Eschweiler-Clarke reaction is a chemical reaction whereby a primary (or secondary) amine is methylated using excess formic acid and formaldehyde. Reductive amination reactions such as this one will not produce quaternary ammonium salts, but instead will stop at the tertiary amine stage.

Thiamine is a vitamin, also called vitamin B1. Which of the following is a synthetic derivative of thiamine ?

  1. Allithiamine

  2. Benfotiamine

  3. Prosultiamine

  4. Sulbutiamine


Correct Option: D
Explanation:

Sulbutiamine is a synthetic derivative of thiamine (vitamin B1). As a dimer of two modified thiamine molecules, it is a lipophilic compound that crosses the blood-brain barrier more readily than thiamine and increases the levels of thiamine and thiamine phosphate esters in the brain.

CoA is an important molecule in metabolism. Which of the following is required to synthesize coenzyme-A?

  1. Thiamine

  2. Riboflavin

  3. Niacin

  4. Pantothenic acid


Correct Option: D
Explanation:

Pantothenic acid, is a water-soluble vitamin. For many animals, pantothenic acid is an essential nutrient. Animals require pantothenic acid to synthesize coenzyme-A (CoA), as well as to synthesize and metabolize proteins, carbohydrates, and fats.

Which of the following can be excluded from the category of thermosetting plastics?

  1. Polycarbonates

  2. Polymethyl methacrylate

  3. Acrylonitrile butadiene styrene

  4. None of these


Correct Option: D
Explanation:

All are the thermosetting plastics.

Vitamin D is obtained from exposure to Sun. Among the following ----------------- is a form of vitamin D.

  1. phylloquinone

  2. cholecalciferol

  3. ascorbic acid

  4. cyanocobalamin


Correct Option: B
Explanation:

Cholecalciferol is a form of vitamin D, also called vitamin D3 or calciol. It is structurally similar to steroids such as testosterone, cholesterol, and cortisol (though vitamin D3 itself is a secosteroid).

The ----------------- polymer is used as an insulator in the electrical and electronics industries.

  1. polybutylene terephthalate

  2. Polyethylene terephthalate

  3. Polyoxymethylene

  4. Nylon 6,6


Correct Option: A
Explanation:

Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer, that is used as an insulator in the electrical and electronics industries. It is a thermoplastic (semi-)crystalline polymer, and a type of polyester.

The exoskeletons of arthropods consist of ------------------ polymer.

  1. starch

  2. Glycogen

  3. chitin

  4. Cellulose


Correct Option: C
Explanation:

Chitin is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world. It is the main component of the cell walls of fungi, the exoskeletons of arthropods such as crustaceans (e.g., crabs, lobsters and shrimps) and insects, the radulas of mollusks, and the beaks of cephalopods, including squid and octopuses.

Whichj of the following is a three-dimensional structure of a protein?

  1. Primary structure

  2. Secondary structure

  3. Tertiary structure

  4. Quaternary structure


Correct Option: C
Explanation:

Tertiary structure is the final three-dimensional structure of a protein, which results from a large number of non-covalent interactions between amino acids.

Beta blockers are the drugs that counteract the stimulatory effects of adrenaline.Which of the following is a beta blocker?

  1. Tryptamine

  2. Melatonin

  3. Auxins

  4. Pindolol


Correct Option: D
Explanation:

Pindolol is a nonselective beta blocker with partial beta-adrenergic receptor agonist activity. It possesses ISA (Intrinsic Sympathomimetic Activity). This means that pindolol, particularly in high doses, exerts effects like epinephrine or isoprenaline (increased pulse rate, increased blood pressure, bronchodilation), but these effects are limited.

Lymphocytes are complex cells that direct the body's immune system. Which of the following amino acids stimulates the lymphocyte production in the body?

  1. Alanine

  2. Asparagine

  3. Citrulline

  4. Creatine


Correct Option: A
Explanation:

Alanine is necessary for the maintainance of proper blood glucose level from dietary protein. It stimulates lymphocyte production and may help people who have immune suppression. It also strengthens the immune system by producing antibodies.

Cardiac muscles are involuntary striated muscles found in the walls of the heart.These muscles are regulated by --------------------- amino acids.

  1. serine

  2. taurine

  3. threonine

  4. tyrosine


Correct Option: B
Explanation:

Taurine helps regulate the contraction and pumping action of the heart muscle and it helps regulate blood pressure and platelet aggregation.

Myelin sheath is the insulating envelope surrounding the nerve fibre and facilitates the transmission of nerve impulses. Which of the following amino acids helps in the maintenance of the myelin sheaths?

  1. Cysteine

  2. Histidine

  3. Glutamine

  4. Glutathione


Correct Option: B
Explanation:

Histidine is known to be vital in the maintenance of the myelin sheaths surrounding nerves, particularly the auditory nerve and is used to treat some forms of hearing disability.

The nitrogen balance in adults is maintained by

  1. isoleucine

  2. L-arginine

  3. L-carnosine

  4. leucine


Correct Option: A
Explanation:

Isoleucine is necessary for the optimal growth of infants and for maintaining nitrogen balance in adults.

Amino acids are the building blocks of proteins. Which among the following is an amino acid?

  1. Indole

  2. Pyrrole

  3. Tryptophan

  4. Serotonin


Correct Option: C
Explanation:

Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG.

Among the following --------------------------- is a flammable polycyclic hydrocarbon .

  1. isoindoline

  2. indoline

  3. indene

  4. indole


Correct Option: C
Explanation:

Indene is a flammable polycyclic hydrocarbon with chemical formula C9H8. It is composed of a benzene ring fused with a cyclopentene ring. This aromatic liquid is colourless although samples often are pale yellow.

Which of the following amino acids reduces stress and anxiety ?

  1. L-theanine

  2. Lysine

  3. Phenylalanine

  4. Proline


Correct Option: A
Explanation:

L-theanine reduces stress and anxiety without the tranquilizing effects found in many other calming supplements.

The heme is a deep red, nonprotein, ferrous component of hemoglobin. Its porphyrins consist of

  1. Benzene

  2. Pyrroles

  3. Carbazole

  4. 1-Methylindole


Correct Option: B
Explanation:

Pyrroles are components of more complex macrocycles, including the porphyrins of heme, the chlorins, bacteriochlorins, chlorophyll, porphyrinogens. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme.

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