Chemistry (Part-XVI)

Total Questions: 50

41. Incomplete combustion of fuels like petrol and diesel produces _____ . [S.S.C. Online CHSL (T-I) 15.03.2018 (Shift-II) ]

Correct Answer: (b) carbon monoxide
Solution:Fuels like petrol, diesel, and coal in the presence of less oxygen i.e. their incomplete combustion produce carbon monoxide gas. Carbon (C) is found in these fuels. Carbon is left behind by incomplete combustion, which then produces CO (carbon monoxide). This is a toxic gas.

42. Automobile emissions promote toxic pollutants called- [S.S.C. Online CHSL (T-I) 11.01.2017 (Shift-I) ]

Correct Answer: (c) carbon monoxide
Solution:Carbon monoxide is a colorless gas. This gas is slightly lighter in the air. Its molecular formula is CO. When its excessive amount enters the body, suffocation occurs, after which unconsciousness comes and leads to death. It is found in the smoke from automobile vehicles.

43. Which of the following gases is produced due to incomplete combustion of fuel? [S.S.C. Online CHSL (T-I) 18.01.2017 (Shift-II) ]

Correct Answer: (b) Carbon Monoxide
Solution:Incomplete combustion of a fuel produces carbon monoxide (CO) gas. Combustion of fuel in the presence of less oxygen is considered incomplete combustion because due to lack of oxygen, all the oxygen rapidly reacts with the fuel and turns into COâ‚‚ gas. Therefore, the carbon (C) of the remaining fuel reacts with the CO, present in the atmosphere to form carbon monoxide (CO).

44. Which of the following gases emitted from automobile exhaust is poisonous? [S.S.C. Online CHSL (T-I) 16.01.2017 (Shift-I) ]

Correct Answer: (a) Carbon monoxide
Solution:Carbon monoxide (CO) is a toxic gas. It is often found in the smoke of motor vehicles, which run on petrol, diesel, or gasoline fuels.

45. Which of the following three R's are regarded as environment friendly? [S.S.C. Online Graduate Level (T-I) 11.08.2017 (Shift-II) ]

Correct Answer: (a) reduce, reuse, recycle
Solution:

The "Three Rs" of waste management are a core concept in environmental sustainability. They represent a hierarchy of actions to minimize waste and protect the environment:

  1. Reduce: This is the most effective R, meaning to decrease the amount of waste generated in the first place (e.g., buying products with less packaging, consuming less).
  2. Reuse: Finding new purposes for items or continuing to use them for their original purpose instead of discarding them (e.g., refilling water bottles, donating old clothes).
  3. Recycle: Processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, and reduce air and water pollution (e.g., paper, plastics, glass).

46. The waste management technique that involves the use of micro-organisms to remove or neutral-ize pollutants from contaminated site is called- [S.S.C. Online Graduate Level (T-I) 3.09.2016 (Shift-I) ]

Correct Answer: (c) Bio remediation
Solution:A system of waste management Bio-remediation is a technique in which organic components such as bacteria, fungi, or green plants are used to neutralize or decompose pollutants from soil or water. These micro-organisms convert the contaminants into less harmful substances, they absorb pollutants such as salts, and metallic impurities in their tissues.

47. What are the dissolved and suspended impurities in sewage called? [S.S.C. Online Graduate Level (T-I) 11.08.2017 (Shift-III) ]

Correct Answer: (d) Contaminants
Solution:Impurities suspended in sewage are called contaminants. These are organic chemical substances released into the urban environment, which collect in sewage or sewage through industrial and domestic sources.

48. Which among the following is used in making liquors, medicines and as a fuel in aircrafts? [S.S.C. Online CHSL (T-I) 16.01.2017 (Shift-II) ]

Correct Answer: (c) Ethyl alcohol
Solution:Ethyl alcohol is an organic compound that exists in liquid form at normal temperature and pressure. It is a flammable and volatile compound. The chemical formula of ethyl alcohol is Câ‚‚Hâ‚…OH.

49. Iron and Manganese present as pollutants in water cannot be removed by ____ . [S.S.C. Online Graduate Level (T-I) 7.09.2016 (Shift-II) ]

Correct Answer: (b) chlorination
Solution:By chlorination, micro-organisms such as bacteria present in water can be destroyed, but chlorine reacts with metal impurities like iron and manganese to form soluble salts in water, which cannot be separated by filtration.

50. A genetically engineered form of brinjal known as the BT-brinjal has been developed. The objective of this is- [S.S.C. Online Graduate Level (T-I) 6.09.2016 (Shift-II) ]

Correct Answer: (a) to make it pest resistant
Solution:Bt Brinjal is a new species of brinjal developed by genetic engineering. In this, a special gene (Cry 1 AC) of a bacterium named Bacillus thuringiensis was inserted into the brinjal. Due to this, a type of toxin (BT Taxin) is produced, which generates immunity against insects in brinjal. Thus the purpose of the development of Bt brinjal is to make it insect resistant.