Charles' law states that at constant pressure, volume of a fixed mass of gas is directly proportional to: MCQ with Answer and Explanation

Explanation:
The Contact process produces sulphuric acid: S + O₂ → SO₂; 2SO₂ + O₂ ⇌ 2SO₃ (V₂O₅ catalyst); SO₃ + H₂SO₄ → H₂S₂O₇ (oleum); H₂S₂O₇ + H₂O → 2H₂SO₄. Haber process for NH₃, Ostwald for HNO₃, Solvay for Na₂CO₃.

Explanation:
Boyle's law: P ∝ 1/V at constant temperature and for a fixed mass (number of moles) of gas. If T or n changes, the simple inverse relationship does not hold.

Explanation:
The stratospheric ozone layer absorbs the majority of the sun's harmful ultraviolet (UV-B and UV-C) radiation, preventing it from reaching Earth's surface. UV can cause skin cancer, cataracts, and damage to ecosystems. Ozone depletion is caused by CFCs (chlorofluorocarbons). Infrared is associated with heat, visible light is mostly harmless, radio waves are not absorbed by ozone.