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NON-MEATALS, A . Carbon and its Various Forms

📆 October 22, 2024

Total Questions: 40

31. Which lubricant is used for heavy machines? [R.A.S/R.T.S. (Pre) 1999]

Correct Answer: (c) Graphite
Solution:Graphite lubricant is a thin black, anti-seize and anti-friction carbonic substance. It is an allotrope of Carbon. Graphite grease is used to lubricate industrial and automotive machinery.

32. Which of the following is also used as a lubricant? [M.P.P.C.S. (Pre) 2017]

Correct Answer: (b) Graphite
Solution:Graphite is the pure crystalline allotrope of carbon. It also used as lubricant. In its crystals, the carbon atoms arranged in regular hexagons in layers. Graphite is soft and lubricant due to the presence of weak Vander walls force between its layers.

33. Dry ice is — [Uttarakhand P.C.S. (Pre) 2002, 44th B.P.S.C. (Pre) 2000, 43rd B.P.S.C. (Pre) 1999, 42nd B.P.S.C. (Pre) 1998]

Correct Answer: (c) Solid CO₂
Solution:Dry ice is the common name for solid carbon dioxide (). It's called "dry" because it sublimes (changes directly from solid to gas) without melting into a liquid.

34. Which one of the following is called 'dry ice'? [U.P.P.C.S. (Mains) 2014]

Correct Answer: (d) Solid carbon dioxide
Solution:Dry ice is the common name for solid carbon dioxide (). It's called "dry" because it sublimes (changes directly from solid to gas) without melting into a liquid.

35. 'Dry Ice' is — [Uttarakhand U.D.A./L.D.A. (Mains) 2006, R.A.S/R.T.S. (Pre) 2012]

Correct Answer: (b) Frozen carbon dioxide
Solution:Dry ice sometimes referred to as solid , or dry snow is the solid (frozen) form of carbon dioxide.

36. Chemically Dry Ice is — [Uttarakhand U.D.A./L.D.A. (Mains) 2006, U.P.P.C.S. (Mains) 2009, Jharkhand P.C.S. (Pre) 2010]

Correct Answer: (d) Solid carbon dioxide
Solution:Dry ice is the common name for solid carbon dioxide (). It's called "dry" because it sublimes (changes directly from solid to gas) without melting into a liquid.

37. 'Dry Ice' is — [U.P.U.D.A./L.D.A. (Pre) 2013]

Correct Answer: (c) Solid CO₂
Solution:Dry ice is the common name for solid carbon dioxide (). It's called "dry" because it sublimes (changes directly from solid to gas) without melting into a liquid.

38. Water gas is — [Chhattisgarh P.C.S. (Pre) 2016]

Correct Answer: (a) CO + H₂
Solution:Water gas is a synthesis gas with the mixture of carbon monoxide (CO) and hydrogen (H₂). It is produced by passing steam over red-hot coke or coal. Methyl alcohol is formed by water gas (CH₃OH)-

CO + 2H₂ → CH₃OH

39. The gas, which comes out on opening a soda water bottle, is: [63rd B.P.S.C. (Pre) 2017]

Correct Answer: (a) Carbon dioxide
Solution:Soda water or carbonated water is water that has been infused with carbon dioxide gas under pressure. The gas, which comes out on opening a soda water bottle, is carbon dioxide that produces a bubbly drink.

40. What is the bond order of the CO group? [65th B.P.S.C. (Pre) 2019]

Correct Answer: (d) 3
Solution:In Molecular orbital theory the bond order formula can be defined as half of the difference between the number of electrons in bonding orbitals and antibonding orbitals.

Bond order =1/2 [Nb  - N

Where,

  • Nb = number of bonding electrons
  • N = number of antibonding electrons

CO (Carbon monoxide) molecule has 10 valence electrons:

  • Four from carbon atom.
  • Six from oxygen atom.

Here, Nb=8 . Na=2

Thus, Bond order of CO = 1/2[8−2]=3

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