Which of the following catalysts is used in the hydrogenation of alkenes? MCQ with Answer and Explanation

Explanation:
Extensive properties depend on the amount of substance. Enthalpy (heat content) is extensive because it scales with the quantity. Temperature, density, and refractive index are intensive properties; they remain constant regardless of the sample size. For example, 1 kg of water has more enthalpy than 1 g of water at the same temperature.

Explanation:
Atomic number 8 is oxygen (2,6). It needs 2 more electrons to complete octet, so it gains 2 or shares 2 electrons. Its valency is 2 (typically). It can form two covalent bonds. In H₂O, oxygen forms two bonds.

Explanation:
DAP, (NH₄)₂HPO₄, supplies nitrogen (18% N) and phosphorus (46% P₂O₅). It is a widely used phosphorus-rich fertilizer. Potassium is not present. NPK complex fertilizers provide all three. DAP is highly water-soluble, making phosphorus readily available. In soil, DAP temporarily increases pH around granules due to ammonia, but later nitrification lowers pH. Application: usually at sowing time.