A solution turns methyl orange yellow. Its pH is: MCQ with Answer and Explanation

Explanation:
Graham's law of effusion/diffusion: Rate ∝ 1/√M (molar mass) at same temperature and pressure. Lighter gases diffuse faster. This is used in isotope separation (e.g., ²³⁵UF₆ vs ²³⁸UF₆) and in understanding gas behavior in leaks.

Explanation:
Calorific value is the amount of heat energy released per unit mass or volume of a fuel completely burned. Common units: J/kg, kJ/kg, kcal/kg, Btu/lb. It indicates fuel quality. Hydrogen has ~142 MJ/kg.

Explanation:
SO₂ from burning coal and NOₓ from vehicles form H₂SO₄ and HNO₃ in rain. CO₂ forms weak carbonic acid (normal rain pH ~5.6). Ammonia is basic and neutralizes acidity.