The process of depositing a thin layer of a metal on an object using electricity is called: MCQ with Answer and Explanation

Explanation:
Froth flotation separates sulfide ores from gangue based on their wetting properties. Sometimes, an ore contains multiple sulfides. A depressant (like NaCN) is added to selectively prevent one mineral (e.g., FeS2) from attaching to the froth, allowing only the desired mineral (e.g., PbS) to be separated.

Explanation:
Ethylene (C₂H₄) is systematically named ethene. The -ene suffix indicates a double bond. Ethane is C₂H₆, ethyne (acetylene) is C₂H₂, methane is CH₄. Ethene is an important petrochemical used to make polythene.

Explanation:
Ostwald process: Catalytic oxidation of NH₃ with air over a platinum-rhodium gauze catalyst at ~800°C to form NO, then NO₂, finally absorbed in water to give HNO₃. Fe is Haber catalyst for NH₃. V₂O₅ is for SO₂ oxidation. Ni for hydrogenation. Pt-Rh alloy gauze provides high surface area and mechanical strength, reducing cost. Nitric acid is used in fertilizers (ammonium nitrate), explosives, and nitration.