Kerala Board Class 12 Chemistry — Flashcards for Quick Revision

A: The SI base unit for amount of substance is 'mole' (symbol: mol). It represents the amount of a substance that contains as many elementary entities (atoms, molecules, ions) as there are atoms in exact

A: The mole concept is needed because atoms and molecules are extremely small and present in huge numbers. It's impractical to count them individually. Just like we use 'dozen' for 12 items, we use 'mole

A: Avogadro's constant (Nₐ) is the number of elementary entities present in one mole of any substance. Its value is 6.022 × 10²³ mol⁻¹. This constant helps us connect the microscopic world of atoms and m

A: A mineral is a naturally occurring material in which a metal or its compound occurs. An ore is a mineral from which a metal can be extracted economically. All ores are minerals, but not all minerals a

A: Gold (Au), Silver (Ag), and Mercury (Hg) occur in free state because they have low reactivity and show little affinity for air, moisture, CO₂, or other non-metals. They are called 'noble metals' due t

A: 1. Oxide ores: Haematite (Fe₂O₃) 2. Sulphide ores: Galena (PbS) 3. Carbonate ores: Calamine (ZnCO₃) 4. Halide ores: Rock salt (NaCl) 5. Sulphate ores: Anglesite (PbSO₄)

A: Environment is the biotic and abiotic surroundings with which living things share or interact. Two components: 1. Abiotic components: Air, water, soil, energy radiation, etc. 2. Biotic components: Mi

A: 1. Biosphere: Part of earth where organisms can survive and reproduce 2. Atmosphere: Thin layer of air around earth containing oxygen and water vapour 3. Hydrosphere: Part of earth containing all wate

A: Step 1: SO₂ + O₂ → SO₃ (sulphur trioxide formation) Step 2: SO₃ + H₂O → H₂SO₄ (sulphuric acid formation) Overall: SO₂ + ½O₂ + H₂O → H₂SO₄ Sulphuric acid causes acid rain which damages environment by