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chemistry igcse acapprinted 69 · PDF 69
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printed 69 · PDF 69
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Color Change: The iron changes from a shiny gray to orange-brown (iron (III) chloride color).
Fe is oxidized from 0 to +2.
Reducing Agent:
A reducing agent (reductant) is a substance that loses electrons (is oxidized) in a redox reaction,
causing the reduction of another substance.
Characteristics:
Usually contains elements with lower electronegativity (e.g., metals).
Decreases its oxidation number.
Common Reducing Agents:
Sodium Borohydride (NaBH₄): Used in organic chemistry for reductions.
Zinc (Zn): Commonly used in metal displacement reactions.
Carbon (C): Reduces metal oxides in metallurgy.
Example Reactions:
Zinc Displacing Copper:
Zn+CuSO4→ZnSO4+Cu
Color Change: The blue solution of copper sulfate (CuSO₄) turns colorless, and copper metal is
deposited.
Zn is oxidized from 0 to +2.
Hydrogen as a Reducing Agent:
CuO+H2→Cu+H2O
Color Change: The black copper oxide (CuO) turns into red copper metal.
H₂ is oxidized, and CuO is reduced.