Lesson 14/15 Protection of metals Environmental responsibility

Lesson objectives Describe ways in which metals can be protected against corrosion from oxygen, carbonic acid, and sulphuric acid (9Fc p. 72-3) Describe the three reactions that produce copper sulfate, how we use this chemical, and the environmental and health hazards associated with it (9Eb p.58-9) Discuss acid rain formation and how it can be decreased (9Gb p )

Protection metals from Acid Rain p We know that some metals create their own protection Copper- green copper oxide Aluminium –greyish aluminium oxide Galvanizing Protective layer of zinc carbonate Plating Iron is plated (covered) by a less reactive metal such as tin or nickel

Making Copper Sulphate p.58-9 Copper salts are toxic to living organisms ¾ of the copper sulphate made is used in pesticides Copper sulphide is found in rocks called ores It is heated to create copper oxide and sulphur dioxide Then the copper oxide is mixed with sulphuric acid to make copper sulphate solution 2 CuS + 3O2  2 CuO + 2 SO2 H2SO4 + CuO  CuSO4 + H2O

Equation writing Write the symbol equations for Sulphuric acid + iron oxide  Sulphuric acid + magnesium oxide  Write the reactants needed to make Copper sulphide Iron sulphide Write symbol equations for Sodium hydroxide + hydrochloric acid  Potassium hydroxide + nitric acid (HNO3) 

Environmental Challenges (p.82-3) Increased amounts of CO2 and NO2 and SO2 increase the acidity of rain In the atmosphere they increase global warming and cause climate change When they fall they effects lakes, rivers and soil all living things have a “perfect pH” band which is changed by acid rain

Solutions control air pollution with laws sulphur precipitators in chimneys catalytic converters- convert exhaust gases to less harmful ones

Assessment Tasks (which one?) Read page 59 In your notebook, describe three methods to extract copper sulphide from its ore and how we use it Booklet F9D.d.n F9d3 WS 62 and 63 neutralization and acid rain Moodle internet research ( Power point or poster) Effects of Acid Rain on Metal and Stone buildings