chemistry chemical reactions

CHEMICAL REACTIONS AND EQUATIONS MM 29 1 MARKS What is a double displacement reactions ? give example ? Aluminum burns in chlorine to form aluminum chloride ? Write equations ? Heated iron metal reacts with steam to form iron (2) oxide and hydrogen ? Barium chloride reacts with zinc sulphate to give zinc chloride and barium sulphate ? A shiny brown coloured element X on heating in air becomes black in colour . Name the element X and the black coloured compound formed ? 2 MARKS Why the silver articles tarnish ? What do you mean by precipitation reactions ? Explain the colour changes when copper sulphate solution is put in a iron container ? Explain the displacement reactions between lead and copper chloride with the help of a chemical reactions ? Why should be the magnesium ribbon be cleaned before burning ? What are redox reactions ? explain with an example ? what happens when silver chloride is exposed to sunlight ? How does blackand white photography takes place ? Explain wth the help of a equation ? What happens when silver nitrate solution is added to sodium chloride solution ? explain with a chemical equation ? How do corrosion become advantageous in the case of aluminum ? Why does the medal of bronze turn green in moist conditions ? What happens when copper reacts with silver nitrate solution ? What is Rancidity? How it can be protected ?