NPK fertiliser provides: MCQ with Answer and Explanation

Explanation:
Electrolysis of water produces pure hydrogen and oxygen: 2H₂O → 2H₂ + O₂. Hydrogen is used in fuel cells to generate electricity. It can also be produced by steam reforming of natural gas, but electrolysis yields clean hydrogen if powered by renewable energy. Combustion of methane produces energy, not hydrogen. Neutralization gives salt and water.

Explanation:
CO removes oxygen from Fe₂O₃ – it's a redox reaction. Also, CO displaces Fe, making it a displacement. So both redox and displacement.

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.