Chemistry (Part-X)

Total Questions: 50

11. Ethanol is produced by which process? [S.S.C. Online Constable GD 2.03.2019 (Shift-I) ]

(a) Salinization
(b) Combination
(c) Titration
(d) Fermentation

Correct Answer: (d) Fermentation

Solution:Ethanol (ethyl alcohol) is most commonly produced industrially and biologically through the process of fermentation. This is a metabolic process where microorganisms, typically yeast, convert sugars (like glucose) into ethanol and carbon dioxide in the absence of oxygen.

12. What will be the formula of fructose? [C.P.O. S.I. 6.06.2016 (Shift-I) ]

(a) C₁₂H₂₂O₁₁
(b) C₆H₁₂O₆
(c) C₁₂H₁₉Cl₃O₈
(d) C₆H₁₀O₈

Correct Answer: (b) C₆H₁₂O₆

Solution:Fructose is a monosaccharide, a simple sugar. It has the same chemical formula as glucose, which is C₆H₁₂O₆. They are isomers, meaning they have the same molecular formula but different structural arrangements.

(a) C₁₂H₂₂O₁₁ is the formula for disaccharides like sucrose (table sugar) or lactose.
(c) C₁₂H₁₉Cl₃O₈ is the formula for Sucralose (a sugar substitute).
(d) C₆H₁₀O₈ is not a common sugar formula.

13. _______ the correct formula for ammonium phosphate. [S.S.C. Online MTS (T-I) 9.10.2017 (Shift-I) ]

(a) N₄H₆ PO₄
(b) (NH₄)₃ PO
(c) (NH₄)₃ PO₄
(d) (NH₄)₂ PO₄

Correct Answer: (c) (NH₄)₃ PO₄

Solution:The formula for ammonium phosphate is [(NH₄)₃ PO₄].

14. Which of the following acts as best adsorbent? [S.S.C. Online Graduate Level (T-I) 9.09.2016 (Shift-II) ]

(a) Charcoal
(b) Activated Charcoal
(c) Activated Coconut Charcoal
(d) Carbon Black

Correct Answer: (c) Activated Coconut Charcoal

Solution:Adsorption is the process where molecules adhere to a surface. Activated charcoal is known for its excellent adsorptive properties due to its highly porous structure and large surface area. Among the given options, activated coconut charcoal is generally considered one of the best forms of activated charcoal because coconut shells produce activated carbon with a particularly high microporosity, making it very effective for adsorbing various substances, especially gases and organic compounds.

15. Particulates (< 1 µm size) remaining suspended in air indefinitely and transported by wind currents are called— [S.S.C. Online Graduate Level (T-I) 10.09.2016 (Shift-II) ]

(a) Mists
(b) Fumes
(c) Aerosols
(d) Smoke

Correct Answer: (c) Aerosols

Solution:Aerosols are suspensions of fine solid particles or liquid droplets in a gas. Particles less than 1 µm (micrometer) in size are typically small enough to remain suspended in the air for extended periods and can be transported over long distances by wind currents.

(a) Mists are usually liquid droplets, often larger.
(b) Fumes are very fine solid particles formed by condensation of vapors.
(d) Smoke consists of solid and liquid particulate matter resulting from incomplete combustion, which can include larger particles

16. Which one of the following is commonly used for pulp bleaching in the paper industry? [S.S.C. Online Graduate Level (T-I) 9.09.2016 (Shift-III) ]

(a) Mild Sulphuric Acid
(b) Glucose Isomerase
(c) Hydrogen Peroxide
(d) Iodine and Water

Correct Answer: (c) Hydrogen Peroxide

Solution:Hydrogen peroxide (H₂O₂) is a completely chlorine-free bleaching agent. Its use in the paper industry has increased because it can be used easily and the cost is also low. Hydrogen peroxide is also used to soft bleach objects like silk, wool, feathers, hair, straws, ivory, etc.

17. The three-carbon molecules broken down from six-carbon molecules of glucose during the first step in the process of nutrition in all organisms is called: [S.S.C. Online CHSL (T-I) 12.10.2020 (Shift-III) ]

(a) Pyruvate
(b) Ethane
(c) Methane
(d) Butane

Correct Answer: (a) Pyruvate

Solution:The first step in the breakdown of glucose (a six-carbon molecule) to extract energy in most organisms is glycolysis. During glycolysis, one molecule of glucose is broken down into two molecules of a three-carbon compound called pyruvate (also known as pyruvic acid).

18. What is the function of a catalyst in a chemical reaction? [S.S.C. Online CHSL (T-I) 10.01.2017 (Shift-III) ]

(a) changes the potential energy of the factors.
(b) changes the kinetic energy of the factors.
(c) changes the potential energy of the products.
(d) changes activation energy.

Correct Answer: (d) changes activation energy.

Solution:A catalyst is a substance that increases the rate of a chemical reaction without itself being consumed in the process. It achieves this by providing an alternative reaction pathway with a lower activation energy. Catalysts do not change the potential energy of reactants or products, nor do they change the overall enthalpy change of the reaction; they simply make it easier for the reaction to occur.

19. Which chemical compound, with the chemical formula CH₃CH₂Cl, is used as a blowing agent in foamed plastics? [S.S.C. Online CHSL (T-I) 08.06.2022 (Shift-I) ]

(a) 3-Chlorohexane
(b) 1-chloropropane
(c) Chloromethane
(d) Chloroethane

Correct Answer: (d) Chloroethane

Solution:Chloroethane with the chemical formula CH₃CH₂Cl is used as a blowing agent in foamed plastics. It was a promoter chemical in the aluminium chloride-catalyzed process to produce ethylbenzene. Now, it is not widely used in any of these roles.

The chemical formula of 3-Chlorohexane is C₆H₁₃Cl.
n-Propyl chloride (also 1-propyl chloride or 1-chloropropane) is a colourless, flammable chemical compound. It has the chemical formula C₃H₇CI.
Chloromethane, also called methyl chloride, Re-frigerant-40, R-40 or HCC - 40, is an organic compound with the chemical formula CH₃Cl.

20. The model of action proposed by J.J. Thomson is commonly called the _______ model. [C.P.O. S.I. 5.06.2016 (Shift-I) ]

(a) Cream and Cake
(b) Plum and Pudding
(c) Plum and Cake
(d) Cream and Pudding

Correct Answer: (b) Plum and Pudding

Solution:J.J. Thomson proposed the "plum pudding model" of the atom in 1904. In this model, the atom was envisioned as a sphere of uniformly distributed positive charge, with negatively charged electrons ("plums") embedded within it, much like raisins in a plum pudding. This model was later disproven by Rutherford's gold foil experiment.

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