Tamil Nadu Board Class 12 Chemistry — Flashcards

A: Mineral: A naturally occurring substance containing metal in free state or as compounds (oxides, sulphides, silicates, etc.). Example: Iron is present in 800 minerals. Ore: A mineral containing high

A: The three main steps are: 1. Concentration of ore: Removal of gangue (non-metallic impurities and rocky materials) to increase metal concentration. 2. Extraction of crude metal: Conversion of ore in

A: Balanced equation: 4Au(s) + 8CN⁻(aq) + O₂(g) + 2H₂O(l) → 4[Au(CN)₂]⁻(aq) + 4OH⁻(aq) Explanation: - Gold is converted to soluble cyanide complex [Au(CN)₂]⁻ - Gangue (aluminosilicate) remains insoluble

A: According to Arrhenius concept, an acid is a substance that dissociates to give hydrogen ions (H⁺ or H₃O⁺) in aqueous solution. Example: HCl(g) + H₂O(l) → H₃O⁺(aq) + Cl⁻(aq). Limitation: Does not expl

A: Lowry-Bronsted theory defines: Acid = proton (H⁺) donor; Base = proton acceptor. Example: HCl + H₂O ⇌ H₃O⁺ + Cl⁻. Here HCl is acid (donates H⁺), H₂O is base (accepts H⁺). Advantage: Explains basic beh

A: Lewis acid = electron pair acceptor; Lewis base = electron pair donor. In BF₃ + NH₃ → F₃B-NH₃: BF₃ is Lewis acid (has vacant 2p orbital, accepts electron pair), NH₃ is Lewis base (has lone pair on N,

A: p-block elements have the general electronic configuration: ns² np¹⁻⁶ Where: - n is the principal quantum number (increases down the group) - ns² indicates the completely filled s-orbital - np¹⁻⁶ ind

A: Group 18 elements have completely filled p-orbitals with the configuration ns² np⁶. Reasons for inertness: 1. Complete valence shell with 8 electrons (octet) 2. Maximum stability due to filled p-orbi

A: The group oxidation state equals the total number of valence electrons: Group 13 (ns² np¹): Highest oxidation state = +3 Group 14 (ns² np²): Highest oxidation state = +4 Group 15 (ns² np³): Highest o