NPK fertilizer supplies which primary nutrients? MCQ with Answer and Explanation

Explanation:
Aluminium is highly reactive; its oxide cannot be reduced by carbon. Hall-Héroult process electrolyzes alumina dissolved in molten cryolite (Na₃AlF₆) using carbon anodes.

Explanation:
Isotopes have identical atomic numbers (number of protons) but different mass numbers due to different numbers of neutrons. They have similar chemical properties but different physical properties like mass and density. Example: ¹²C and ¹⁴C, both have 6 protons.

Explanation:
A negative catalyst (inhibitor) slows down a reaction. Phosphoric acid (or acetamide) retards the decomposition of H₂O₂ by stabilizing it. MnO₂ is a positive catalyst for H₂O₂ decomposition, speeding it up. Platinum catalyzes SO₂ oxidation in contact process. Iron (Fe) catalyzes ammonia synthesis in Haber process. Negative catalysts are often used to prevent undesirable reactions, e.g., antioxidants in food preservation.