Match the following columns. Column I (Alloys name) Column II(Composition) (i) Stainless steel (a) P b and S n (ii) Magnalium (b) F e , C r , N i and C (iii) Brass (c) A l and M g (iv) Solder (d) C u and Z n

(i) Stainless steel is an alloy of iron, chromium, nickel and carbon. It is used in making surgical instruments. (ii) Magnalium is an alloy of aluminium and magnesium. It is used in making metal mirrors. (iii) Brass is an alloy of copper and zinc. It is used in making parts of watches. (iv) Solder is an alloy of lead and tin. It is used in welding and soldering. Column I (Alloys name) Column II (Composition) (i) Stainless steel (b) Fe , Cr , Ni and C (ii) Magnalium (c) Al and Mg (iii) Brass (d) Cu and Zn (iv) Solder (a) Pb and Sn

Name the process by which impure ore of aluminium gets purified by using concentrated solution of an alkali.

Bayer's process is the process used for the purification of the impure ore of aluminium using concentrated solution of an alkali. In this process, finely powdered ore is treated with hot solution of sodium hydroxide.

Name the most common ore of the metal aluminium from which the metal is extracted. Write the chemical formula of the ore.

The most common ore of aluminium is the bauxite. It is an oxide ore. Bayer's process is used to obtain pure aluminium oxide from the bauxite ore. The chemical formula is A l 2 O 3 . The metal is extracted from this ore using the process called Hall-Heroult's process which involves the process of electrolysis.