Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Which of the following is not a correct statement about Bitumen?
[A] It’s a mixture of highly condensed polycyclic aromatic compounds
[B] Its is soluble in Carbon Disulphide
[C] SARA analysis is used to determine bitumen chemistry
[D] All of above are correct statements
Show Answer
Correct Answer: D [ All of above are correct statements ]
Notes:
Bitumen is a mixture of organic liquids that are highly viscous, black, sticky, soluble in carbon disulfide and composed of highly condensed polycyclic aromatic hydrocarbons.
2. Which among the following elements are generally find in free state?
[A] Group 11 elements
[B] Group 12 elements
[C] Group 13 elements
[D] Group 14 elements
Show Answer
Correct Answer: A [Group 11 elements ]
Notes:
Group 11 is also known as the coinage metals, due to their former usage. They were most likely the first three elements discovered. Copper, silver, and gold all occur naturally in elemental form.
3. In what form is Nitrogen present in Urea?
[A] Nitrite
[B] Nitrate
[C] Ammonium
[D] Amide
Show Answer
Correct Answer: D [Amide]
Notes:
Urea is an organic compound with the formula (NH2)2CO. The Nitrogen present in Urea is in the form of Amide. This compound is highly soluble in water and is a very effective source of Nitrogen for plants. It is the main nitrogenous end product of the metabolic breakdown of proteins in all mammals and some fishes.
4. How many noble gases occur naturally?
[A] Three
[B] Four
[C] Five
[D] Six
Show Answer
Correct Answer: D [Six]
Notes:
Noble gases are characterized by their low reactivity. The reason for this is their full electron shell, which makes them very stable and unlikely to engage in chemical reactions. The six noble gases that occur naturally are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn). Despite the inertness of noble gases, some of them like Xenon are known to form compounds.
5. L.P.G. is a hydrocarbon consisting of a mixture of :
[A] Methane and Butane
[B] Propane and Butane
[C] Ethane and Propane
[D] Ethane and Butane
Show Answer
Correct Answer: B [Propane and Butane]
Notes:
L.P.G. (Liquefied Petroleum Gas) primarily consists of propane and butane. It is used as fuel for heating, cooking, and vehicles. Propane (C3H8) and butane (C4H10) are both byproducts of natural gas processing and petroleum refining. LPG is favored for its high energy content and clean-burning properties.
6. Ilmenite, which is widely distributed along the Indian coastal lines is a mineral of __?
[A] Tungsten
[B] Titanium
[C] Gallium
[D] Tin
Show Answer
Correct Answer: B [Titanium]
Notes:
Ilmenite (FeO.TiO2) is important titanium mineral. It is widely distributed along the Indian coastal lines. With proven reserves exceeding 270 million tonnes, about 37 per cent of the total world Ilmenite reserves are located in the beach sands of the southern peninsular India. Titanium known for its excellent corrosion resistance, high strength and low density, is widely used for aero-engine and airframe structures in both civilian and military aircraft. Titanium-alloy components also find applications in satellite launch vehicles, rockets and missiles. As of now, India’s total titanium requirement is being met by imports even though it possesses a large reserve base of titanium minerals.
7. The adsorption of hydrogen by palladium is termed as:
[A] Physisorption
[B] Chemisorptions
[C] Physical adsorption
[D] Occlusion
Show Answer
Correct Answer: D [ Occlusion]
Notes:
The adsorption of hydrogen by palladium is called occlusion. Occlusion is a type of adsorption where gases are adsorbed onto metals. The hydrogen adsorbed onto palladium is called occluded hydrogen.
Palladium can absorb about 900 times its own volume of hydrogen. The hydrogen that is adsorbed is more active than normal hydrogen.
The adsorption of hydrogen on palladium occurs through a hydride formation. The chemical bonds that are formed cannot be broken easily to release the hydrogen gas from the surface of the metal.
The process of occlusion is used to purify hydrogen.
8. Which of the following is the composition of vinegar?
[A] 65-75% solution of acetic acid in water
[B] 45-60% solution of acetic acid in water
[C] 28-35% solution of acetic acid in water
[D] 5-8% solution of acetic acid in water
Show Answer
Correct Answer: D [5-8% solution of acetic acid in water]
Notes:
5-8% solution of acetic acid in water is called vinegar and is used widely as a preservative in pickles
9. Which of these is NOT a compound of carbon?
[A] Acetic acid
[B] Chloroform
[C] Caustic Soda
[D] Methane
Show Answer
Correct Answer: C [Caustic Soda]
Notes:
Caustic soda is a compound of sodium where as Acetic acid, Chloroform and Methane are the compounds of carbon.
10. Which of the following is NOT correct about Ethanol?
[A] It is a good solvent
[B] It gives out hydrogen when reacted with Sodium
[C] It is an odorless liquid
[D] All are correct
Show Answer
Correct Answer: C [It is an odorless liquid]
Notes:
Ethanol is a good solvent and reacts with sodium leading to the evolution of hydrogen. It is a colorless liquid with a slight characteristic odor.