The process of separating petroleum into petrol, kerosene, diesel etc. is: MCQ with Answer and Explanation

Explanation:
Atomic number 8 is oxygen (2,6). It needs 2 more electrons to complete octet, so it gains 2 or shares 2 electrons. Its valency is 2 (typically). It can form two covalent bonds. In H₂O, oxygen forms two bonds.

Explanation:
Crude petroleum is heated and the vapors are passed through a fractionating column where they condense at different levels according to boiling points. Fractions: petrol (40-120°C), kerosene (150-250°C), diesel (250-350°C), lubricating oil, etc. This is a continuous process. The column has trays and maintains temperature gradient. Simple distillation cannot separate close boiling mixtures.

Explanation:
Catalysts provide an alternative reaction pathway with lower activation energy, increasing the fraction of effective collisions. They are not consumed and do not alter the overall enthalpy change (ΔH) or equilibrium constant.