Which of the following statements about cathode rays is incorrect? MCQ with Answer and Explanation

Explanation:
Acid rain results from SO₂ and NOₓ (oxides of nitrogen) dissolving in water vapor to form sulfuric and nitric acids. These are released from burning fossil fuels and industrial processes. Carbon dioxide forms weak carbonic acid (normal rain pH ~5.6), but SO₂ and NOₓ cause pH below 5.0.

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:
PVC (polyvinyl chloride) is an addition polymer of vinyl chloride monomer (CH₂=CHCl). It is used for pipes, cables, flooring, and medical equipment. Teflon from tetrafluoroethene, polythene from ethylene, nylon is a polyamide (condensation polymer). PVC can be rigid or flexible depending on plasticizers added. It is a thermoplastic. Disposal of PVC by burning produces toxic HCl gas.