Which one of the methods given in column I is applied for the extraction of each of the metals given in Column II. Column I Column Il Electrolytic reduction Aluminium Reduction with Carbon Zinc Reduction with Aluminium Sodium Iron Manganese Tin

Oxides of strong electropositive metals, such as K , Ca , Na , Al and Mg are very stable. It is difficult to reduce them into metallic state by carbon reduction. Such metals are extracted by passing electricity through their fused chlorides/oxides/hydroxides (electrolytic method). The oxides of less reactive metals, such as iron, form less stable oxides and other compounds. Relatively little energy is needed to reduce them to extract the metal. Less reactive metal, such as iron, may be extracted by reduction with carbon. Aluminium has a very strong affinity for oxygen. It reduces the oxides of chromium and manganese to the metallic forms. Aluminium is more electropositive than Cr or Mn . Hence, aluminium metal is frequently used as reducing agent for the extraction of metal such as chromium or manganese from their respective oxides. The process of reduction is known as aluminothermy. Cr 2 O 3 Chromium oxide + 2 Al Aluminium → Heat Al 2 O 3 Aluminium oxide + 2 Cr Chromium 3 Mn 3 O 4 Manganese tetroxide + 8 Al Aluminium → Heat 4 Al 2 O 3 Aluminium oxide + 9 Mn Manganese Column I Column Il Electrolytic reduction Aluminium, Sodium Reduction with Carbon Zinc, Iron, Tin Reduction with Aluminium Manganese

Corrosion is the damage caused to the metal by the chemical reaction of air, water and acids with the surface of the metal. Generally reactive metals corrode easily and non-reactive metals have good resistance to corrosion. For example, Copper reacts with moist carbon dioxide in the air and gets a green coat of copper carbonate.

Give the name and chemical formula of one ore of copper.

Copper glance is the name of the ore of copper and its chemical formula is Cu 2 S . It is a sulphide ore of Copper. Note: The main copper sulphide minerals are chalcopyrite ( CuFeS 2 ) chalcocite ( Cu 2 S ) , covellite ( CuS ) , bornite ( Cu 5 FeS 4 ) , tetrahedrite and enargite. The largest source of copper is from porphyry ore deposits in which one or a combination of the aforementioned minerals occurs.

Why do we apply paint on iron articles?

By painting the iron article we can prevent rusting. It prevents the contact of air and moisture with the iron that causes iron to rust. After painting iron surface does not come in contact with moisture and air which cause rusting.

Differentiate between metals and non-metals on the basis of their chemical properties.

Chemical properties of metals Chemical properties of non-metal Metals forms basic oxides. Non-metals forms acidic or neutral oxides. Chemical properties of metals Chemical properties of non-metal Metals displace hydrogen from water. Non-metals do not react with water. Chemical properties of metals Chemical properties of non-metal Metals displace hydrogen from dilute acids. Non-metals do not react with dilute acids.