Free NEET Chemistry Questions and Answers — Questions and Answers
Question 1: The chloramine-T is.
- antiseptic
- analgesic
- disinfectant (Correct answer)
- antipyretic
Correct answer: disinfectant
Chloramine-T is an organic compound that releases chlorine, making it a potent oxidizing agent. It is widely used as a disinfectant and antiseptic due to its effectiveness against bacteria, viruses, and fungi. Its applications range from medical and dental settings to water purification.
Question 2: Benzalkonium chloride is an
- anionic surfactant and soluble in most of the organic solvents
- cationic surfactant and antiseptic (Correct answer)
- cationic surfactant and insoluble in most organic solvents.
- cationic surfactant and antimalarial
Correct answer: cationic surfactant and antiseptic
Benzalkonium chloride is a quaternary ammonium compound characterized by its cationic surfactant properties. As a surfactant, it disrupts cell membranes, which makes it highly effective as an antiseptic and disinfectant. It is commonly found in various consumer products, including hand sanitizers, wound disinfectants, and eye drops.
Question 3: Interferon is connected to
- virus (Correct answer)
- tonic
- ore of iron
- carbohydrate
Correct answer: virus
Interferons are a group of signaling proteins produced and released by host cells in response to the presence of pathogens, most notably viruses. They play a crucial role in the innate immune system by interfering with viral replication and activating other immune cells. This makes them a key component of the body's defense against viral infections.
Question 4: Ibuprofen has
- both R and S enantiomers are active pain killers
- the racemic mixture of both R and S enantiomer (Correct answer)
- only S-enantiomer
- only R-enantiomer
Correct answer: the racemic mixture of both R and S enantiomer
Ibuprofen is a chiral drug, meaning it exists as two enantiomers: R-ibuprofen and S-ibuprofen. While S-ibuprofen is primarily responsible for its anti-inflammatory and analgesic effects, commercial ibuprofen is typically sold as a racemic mixture containing equal amounts of both R and S enantiomers. The R-enantiomer can be converted to the active S-enantiomer within the body.
Question 5: Which one of the following substances is a hypnotic?
- chemisol
- catechol
- salol
- luminal (Correct answer)
Correct answer: luminal
Luminal is a brand name for phenobarbital, which belongs to the class of barbiturates. Barbiturates are central nervous system depressants that produce effects ranging from mild sedation to general anesthesia. They are commonly used as hypnotics (sleep-inducing drugs) and anticonvulsants due to their ability to slow brain activity.
Question 6: Which of the following is the method through which H2SO4 is used to manufacture detergents?
- p-Nitrophenol
- Cyclohexanol
- Lauryl alcohol (Correct answer)
- cholesterol
Correct answer: Lauryl alcohol
Many synthetic detergents, particularly alkyl sulfate detergents, are manufactured through the sulfonation of long-chain alcohols. Lauryl alcohol (dodecanol) is a common starting material that reacts with concentrated sulfuric acid (H2SO4) to form lauryl hydrogen sulfate. This intermediate is then neutralized to produce sodium lauryl sulfate, a widely used anionic surfactant in various cleaning products.
Question 7: Of the following, which won't work as an antacid?
- sodium carbonate
- sodium hydrogen carbonate
- magnesium hydroxide
- aluminium carbonate (Correct answer)
Correct answer: aluminium carbonate
Antacids are mild bases designed to neutralize excess hydrochloric acid in the stomach. Sodium carbonate, sodium hydrogen carbonate (baking soda), and magnesium hydroxide (milk of magnesia) are all effective bases commonly used as antacids. Aluminium carbonate, however, is generally insoluble and not effectively utilized as an antacid, making it unsuitable for this purpose.
Question 8: The primary reason for stomach acidity is
- release of extra bile juice which increases alkaline medium in the stomach
- indigestion and pain in the large intestine
- release of extra gastric acids which decrease the pH level (Correct answer)
- release of extra bile juice which increases alkaline medium in the stomach
Correct answer: release of extra gastric acids which decrease the pH level
The stomach naturally produces gastric juice, which contains hydrochloric acid (HCl) to aid digestion and kill pathogens. Stomach acidity, often experienced as heartburn, primarily results from the excessive release of these gastric acids. This overproduction significantly lowers the pH level within the stomach, leading to discomfort and indigestion.
Question 9: Chloramphenicol is a
- broad spectrum analgesic
- broad spectrum antibacterial
- narrow spectrum antibiotic
- broad spectrum antibiotic (Correct answer)
Correct answer: broad spectrum antibiotic
Chloramphenicol is a powerful antibiotic that inhibits bacterial protein synthesis. It is effective against a wide range of both Gram-positive and Gram-negative bacteria, as well as other microorganisms like rickettsiae and chlamydiae. This broad spectrum of activity against various bacterial types classifies it as a broad-spectrum antibiotic.
Question 10: Among the most widely used drugs in medicine iodex is
- o-hydroxy benzoic acid
- methyl salicylate (Correct answer)
- ethyl salicylate
- acetyl salicylic acid
Correct answer: methyl salicylate
Iodex is a well-known topical analgesic balm used for relieving muscular and joint pain. Its primary active ingredient is methyl salicylate, commonly known as oil of wintergreen. Methyl salicylate acts as a counter-irritant and anti-inflammatory agent, providing a warming sensation and pain relief when applied to the skin.
Question 11: The elements in the 3d transition series range in atomic number from
- 21 to 31
- 21 to 30 (Correct answer)
- 22 to 30
- 21 to 29
Correct answer: 21 to 30
The 3d transition series includes elements where the 3d subshell is progressively filled with electrons. This series begins with Scandium (Sc), which has an atomic number of 21, and concludes with Zinc (Zn), which has an atomic number of 30. Therefore, the atomic numbers for this series range from 21 to 30.
Question 12: The first transitional component is
- scandium (Correct answer)
- copper
- nickel
- vanadium
Correct answer: scandium
Transition metals are characterized by having incompletely filled d-orbitals in their common oxidation states. Scandium (Sc), with an atomic number of 21, is the first element in the periodic table to begin filling its 3d subshell, having an electron configuration of [Ar] 3d¹ 4s². Consequently, scandium is recognized as the first transitional component.
Question 13: Transitional metals typically have color because
- of d-d transition (Correct answer)
- their penultimate d-subshells are fully filled
- they absorb electromagnetic radiations
- none of the above
Correct answer: of d-d transition
Transition metal compounds often exhibit vibrant colors due to the presence of partially filled d-orbitals. When white light interacts with these compounds, electrons in lower energy d-orbitals can absorb specific wavelengths and transition to higher energy d-orbitals, a process called d-d transition. The observed color is the complementary color of the light that was absorbed.
Question 14: D-block element atomic radii in a series
- increases with increase in atomic number
- decreases with increase in atomic number (Correct answer)
- remains constant
- none of the above
Correct answer: decreases with increase in atomic number
Across a period (series) in the d-block elements, the atomic radii generally decrease with an increase in atomic number. This trend is primarily due to the increasing nuclear charge, which pulls the valence electrons more strongly towards the nucleus. Although new electrons are added to the inner d-orbitals, the increased nuclear attraction outweighs the shielding effect, leading to a contraction in atomic size.
Question 15: The transition metals become increasingly abundant when interstitial compounds form.
- ductile
- soft
- malleable
- none of the above (Correct answer)
Correct answer: none of the above
Interstitial compounds are formed when small non-metal atoms, such as carbon, nitrogen, or hydrogen, occupy the interstitial voids within the crystal lattice of transition metals. The formation of these compounds typically makes the transition metals significantly harder, more rigid, and increases their melting points. However, they generally become less ductile and less malleable, not more so.
Question 16: There is frequently paramagnetism in
- d-block elements (Correct answer)
- p-block elements
- s-block elements
- any of them
Correct answer: d-block elements
Paramagnetism is a magnetic property arising from the presence of unpaired electrons in an atom or ion, which are attracted to an external magnetic field. D-block elements, or transition metals, frequently have partially filled d-orbitals, leading to the presence of unpaired electrons in their atoms and ions. This characteristic makes them commonly paramagnetic.
Free NEET Chemistry Questions and Answers
The chloramine-T is.