Metals:
Iron :
1. Most automobiles, machine tools, building parts, the hulls of large ships, and machine parts are made out of iron. (Iron metal is strong but is quite cheap. Thus, it is the most common metal in use today.)
2. Iron in the form of steel is used in building parts, cooking pots and pans, cutlery and surgical equipment. It is used in manufacture of aircraft and automobiles. (Most of the iron is converted to steel. Iron is basic constituent in manufacture of Steel).
3. Iron catalysts are used in Haber - Bosch process to generate ammonia.
4. Iron (III) chloride is used in the treatment of sewage, as a dye for cloth, as a coloring agent for paint, an additive in animal feed, an in the manufacture of printed circuit boards.
5. Wrought iron is malleable and is mostly used in ornamental work for gates. (Pure iron is called wrought iron (<0.25% carbon).)
Copper:
1. Copper is used in making wires, electromagnets and electrical relays and switches.
2. Copper is used to pipe water supplies in refrigerators and air conditioning systems.
3. Many musical instruments, especially brass instruments, are made out of copper.
4. It is the basic ingredient of coins for many countries.
5. Copper is taken in use for roofing, plumbing, and cladding. (as it is does not corrode and is malleable and ductile )
Sodium hydroxide:
(i) Used in refining of alumina containing ores (bauxite). The alumina dissolves in sodium hydroxide leaving impurities behind.
(ii) Used in soap manufacture. Sodium hydroxide reacts with fats or oils (esp vegetable oils) to produce soap.
(iii) Sodium hydroxide was also widely used in making paper.
(iv) In the manufacture of biodiesel, sodium hydroxide is taken in use as a catalyst for the transesterification of triglycerides and methanol.
(v) Sodium hydroxide is frequently used as an industrial cleaning agent. It can dissolve grease, oils, fats and protein based deposits.
(vi) It is also used in manufacture of bleach