18.Illustrate an activity to show a double displacement reaction. Give the chemical equation of thereaction that takes place.Long Answer Questions15 marks)Why aluminium sheets do not corrode easily? Why does a copper vessel get covered with a greencoating in rainy season?19.

18.Illustrate an activity to show a double displacement reaction. Give

1.	18.Illustrate an activity to show a double displacement reaction. Give the chemical equation of thereaction that takes place.Long Answer Questions15 marks)Why aluminium sheets do not corrode easily? Why does a copper vessel get covered with a greencoating in rainy season?19.
Answer» Aluminiumwhen reacts with air formsaluminiumoxide which protects the underlyingmetalfrom further oxidation . Thisis notporous and flaky likerustand itcanacts like a film or protective cover which protects themetal. Soaluminium do notrustsCopper vessel get covered with green coating because the metal reacts with CO2 and moisture to form a surface layer of basic copper carbonate Cu2CO3(OH)2 (commonly known as verdigris), which is green.