Railway Science (Chemistry-Carbon And its Compound)

Total Questions: 71

31. Which of the following carbon compounds has a cage-like ring structure shaped like a football? [RRC Group D 26/09/2022 (Afternoon)]

Correct Answer: (b) C - 60 fullerene
Solution:

C - 60 fullerene is one of the allotropes of carbon arranged in the shape of football designed by the US architect Buckminster Fuller that's why also known as Buckminsterfullerene. Both diamond and graphite are formed by carbon atoms, the difference lies in the manner in which the carbon atoms are bonded to one another.

32. Which of the following compounds has 7 covalent bonds? [RRC Group D 29/09/2022 (Afternoon)]

Correct Answer: (a) Ethane
Solution:

33. Which of the following statements about carbon is correct? [RRC Group D 06/10/2022 (Morning)]

Correct Answer: (c) Carbon is non-metal in nature.
Solution:

Atomic number (6), Atomic weight (12), both nonmetallic and tetravalent, Solid at room temperature, makes 4 electrons to form a covalent bond. One of the most important compounds of carbon is charcoal, which is formed when carbon is heated in the absence of air.

34. Which of the following is NOT a carbon compound? [RRC Group D 06/10/2022 (Afternoon)]

Correct Answer: (c) Co(𝑁𝑂₃)β‚‚
Solution:

Cobalt nitrate Co(𝑁𝑂₃)β‚‚) forms red crystals, or pale red powder. Uses - the decoration of porcelain and stones. Carbon compounds - chemical substances containing carbon. The 4 - major categories of it that are present in all living things are carbohydrates, lipids, proteins and nucleic acid.

35. Carbon makes strong bonds with other elements. Which of the following is the correct explanation for the given statement? [RRC Group D 11/10/2022 (Afternoon)]

Correct Answer: (b) A carbon nucleus holds the shared pairs of electrons strongly due to its small size.
Solution:

This is because the small atomic size of carbon enables its nucleus to strongly hold on to the shared pairs of electrons. It forms compounds mainly by covalent bonds.

36. How many number of bonds do the single carbon atoms form? [RRC Group D 11/10/2022 (Evening)]

Correct Answer: (d) 4
Solution:

Properties of Carbon: Tetravalency (Carbon can form 4 covalent bonds with other atoms/elements), Catenation (Carbon has the ability to form long chains when it gets linked with other carbon atoms). Carbon can form single/double/triple bonds. The electronic configuration of Carbon (C) is 1sΒ²2sΒ²2pΒ² .

37. Diamonds can be synthesized by subjecting pure carbon to: [RRB NTPC CBT - I (30/01/2021) Evening]

Correct Answer: (b) very high pressure and high temperature
Solution:

Pure carbon refers to a form of carbon that consists solely of carbon atoms without any other elements or impurities. Carbon can exist in various forms, including diamond, graphite, fullerenes (such as buckyballs), carbon nanotubes, and graphene. Refractive index of diamond is 2.42. Diamond is the hardest known material.

38. Which of the following elements is a versatile element that forms the basis for all living organisms and many of the things we use? [RRB NTPC CBT - I (03/02/2021) Morning]

Correct Answer: (d) Carbon
Solution:

It is a versatile element because it can create four covalent bonds and bond with any element or atoms to form a compound by forming a single, double or triple bond.

39. One carbon credit contains: [RRB NTPC CBT - I (17/02/2021) Evening]

Correct Answer: (d) 1000 kg of carbon dioxide
Solution:

A carbon credit (carbon offsets) is a permit that allows the company that holds it to emit a certain amount of carbon dioxide or other greenhouse gasses. One credit permits the emission of a mass equal to one ton of carbon dioxide.

40. Which of the following is NOT an allotrope of carbon? [RRB NTPC CBT - I (22/02/2021) Morning]

Correct Answer: (d) Carbon dioxide
Solution:

Allotropes - The different forms of the same element. Allotropes of carbon are diamond, graphite, graphene, carbon nanotubes, fullerenes, and carbon nanobuds. Carbon - It is nonmetallic and tetravalent (its atom making four electrons available to form covalent chemical bonds), discovered by Antoine Lavoisier in 1789. Fullerenes (C-60 Buckminsterfullerene) was discovered by Richard Smalley in 1985.