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  • Chemical reactions

    • Introducing chemical reactions - OCR Gateway

      Chemists use symbols and formulae to represent elements, ions and compounds. Chemical equations model the changes that happen in chemical reactions.

    • Avogadro constant and moles - OCR Gateway

      The mole is the unit for amount of substance. The number of particles in a substance can be found using the Avogadro constant. The mass of product depends upon the mass of limiting reactant.

    • Energetics - OCR Gateway

      Exothermic reactions in solution give out energy and the temperature increases, while endothermic reactions take in energy and the temperature decreases. Bonds are broken and made in reactions.

    • Types of chemical reactions - OCR Gateway

      Oxidation is the gain of oxygen and reduction is the loss of oxygen. Neutralisation is the reaction between an acid and a base. Acids react with metals, bases and carbonates to produce salts.

    • Electrolysis - OCR Gateway

      Electrolysis involves using electricity to break down electrolytes to form elements. The products of electrolysis can be predicted for a given electrolyte. Copper can be purified using electrolysis.

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