11 November
Today’s bilingual TNPSC Science–Chemistry notes on Solutions, Colloids and Surface Chemistry — concentration terms, Henry’s law, hardness of water and its removal, Tyndall effect, Brownian movement, emulsions, Hardy–Schulze rule, adsorption and catalysis. 14 key points, detailed notes in English and Tamil, 5 practice MCQs with answers, memory tips and previous-year question patterns for TNPSC Group 1, 2, 2A, 4 and VAO.