Chem 30 Redox

A transfer of electrons. Must have both reduction and oxidation happening for the reaction to occur. The number of electrons gained and lost must be equal.

Formation, decomposition, single replacement, combustion, photosynthesis/cellular respiration.

• -A loss of electrons
• -Becomes more positive
• -Electrons are shown as products
• -Increase in oxidation number
• ex: Fe_(s) + O_2(g) -> Fe₂O_3(s)

• -A gain of electrons
• -Becomes more negative
• -Electrons are shown as reactants
• -Decrease in oxidation number
• ex: NiO_(s) + H_2(g) -> Ni_(s) + H₂O_(l)

A species undergoing reduction that is responsible for the oxidation of another species. Oxidizing agents gain electrons and become more negative.

A species undergoing oxidation that is responsible for the reduction of another species. Reducing agents lose electrons and become more positive.

• An equation where species aren't dissociated.
• ex: Zn_(s) + CuSO_4(aq)-> ZnSO_4(aq) + Cu_(s)

• An equation where all species are dissociated.
• ex: Zn_(s) + Cu²⁺_(aq) + SO₄^2-_(aq) -> Zn²⁺_(aq) + SO₄^2-_(aq) + Cu_(s)

• An equation where species are dissociated and spectators are removed.
• ex: Zn_(s) + Cu²⁺_(aq)+ -> Zn²⁺_(aq) + Cu_(s)

Metal ions and nonmetal atoms because they can accept electrons and become negative.

Metal atoms and nonmetal ions because they can lose electrons and become positive.