Lead-acid batteries (used in automobiles) contain dilute sulfuric acid (H₂SO₄) with specific gravity around 1.25-1.30 when fully charged. It acts as electrolyte and participates in the electrode reactions. Nitric acid is a strong oxidizing agent, HCl is not used because it would produce chlorine, phosphoric acid is in some fuel cells but not lead-acid batteries.
Explanation:
Plaster of Paris (CaSO₄·½H₂O) sets by rehydrating to gypsum (CaSO₄·2H₂O) when mixed with water: CaSO₄·½H₂O + 1½H₂O → CaSO₄·2H₂O. The interlocking crystals of gypsum provide hardness. It expands slightly on setting, making it ideal for casting. Dehydration is the opposite. Oxidation and carbonation are not involved.
Explanation:
Reverse osmosis uses a semipermeable membrane to reject dissolved salts and impurities. Filtration removes solids; chlorination/ozonation disinfect but do not remove salts.
Explanation:
Polycarbonate is a tough, transparent thermoplastic used in bulletproof glass, CDs, and lenses. Polyethylene is for bags; PVC for pipes; Bakelite is thermoset.
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