The document discusses redox reactions, including definitions of oxidation, reduction, oxidizing agents and reducing agents. It provides examples of redox reactions like magnesium burning in oxygen, bromine water oxidizing iron(II) ions, and the displacement of metals in salt solutions. It also describes how electrons are transferred during redox reactions and how redox reactions can occur at a distance using a salt bridge.

1. Mg 2+ O 2- KMnO 4

3. PbO – oxidising agent (experiences reduction Mg – reducing agent ( experiences oxidation) Mg + PbO MgO + Pb Gain of oxygen ---- oxidation Loss of oxygen ---- reduction

4. Cl 2 – oxidising agent ( undergoes reduction ) --- chlorine oxidises hydrogen sulphide to sulphur H 2 S – reducing agent ( undergoes oxidation) --- hydrogen sulphide reduces chlorine to hydrogen chloride Redox reaction H 2 S + Cl 2 2HCl + S Loss of hydrogen --- oxidation Gain of hydrogen --- reduction

36. PREVENTION THE RUSTING OF IRON Coating a layer of metal such as Al or Sn on food tins Applying paint,oil or grease on surface such as engine Wrapping the iron with a layer of plastic . Ex: hangers Applying a coat of Al such as car bumpers or water pipes Iron sheet used as house roofs Are galvanised with a layer of zinc Iron is alloyed with other metals such as chromium or nickel to produce stainless steel Huge iron construction structure such as bridges protected from corrosion by using sacrificial metals(logam korban) such as Mg & Zn

38. K Na Ca Mg Al C Zn Fe Sn Pb Cu Ag Au Reactivity decreases Example : The reaction between Lead(II) oxide with Carbon Observation : burn brightly : produces a grey solids Inference : Carbon is more reactive than Lead Equation : PbO + C Pb + CO 2 If carbon is more reactive than metal X , a flame or glows(baraan) can be seen . If carbon is less reactive than metal Y ,the flame or glows will not be seen when carbon react with metal oxide Y is heated . The position of Carbon in the R. S.

40. PREPARED BY PN ZAINAB BINTI AYUB 22 JULY 2008