Which catalyst is used in the hydrogenation of unsaturated vegetable oils? MCQ with Answer and Explanation

Explanation:
Petroleum (crude oil) and natural gas are formed from the remains of tiny marine organisms (plankton) that settled on the seabed, buried under sediment, and transformed by heat and pressure over millions of years. Coal is formed from terrestrial plant material in swampy conditions. Biogas is produced by anaerobic decomposition of organic waste. Charcoal is produced by destructive distillation of wood.

Explanation:
Boyle's law: P₁V₁ = P₂V₂. Given P₁=1.0 atm, V₁=2.0 L, P₂=4.0 atm. V₂ = (1.0 × 2.0) / 4.0 = 0.5 L. Volume decreases as pressure increases, because gas is compressible. The product PV is constant for a fixed mass of gas at constant T. Scuba divers experience this; as they dive deeper, pressure increases, reducing air volume in lungs.

Explanation:
Calorific value is the energy released per unit mass or volume of fuel. Common units: kJ/kg, kJ/g, J/g, kcal/kg, Btu/lb. It measures fuel efficiency. Hydrogen has about 141.9 MJ/kg (higher), petrol ~47 MJ/kg. Temperature (°C) is not a unit for calorific value. Pressure and concentration are not appropriate.