KERALA PSC / CHEMISTRY / METALS, NONMETALS & METALLURGY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

 

KERALA PSC / CHEMISTRY / METALS, NONMETALS & METALLURGY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / METALS, NONMETALS & METALLURGY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

·      Metallurgy is the process of extracting metal, in a pure state on a large scale from its ore by physical and chemical means

·      Ore is the mineral from which the metal is conveniently and economically extracted

·      Ore has definite composition (formula)

·      Clay is the mineral of aluminium

·      Minerals are solid, naturally occurring as deposits in the earth’s crust and contain metals in the combined state, along with associated earthly impurities (gangue).

·      Bauxite and cryolite are the main ores of Aluminium

·      Sulphide ores are purified by Froth-floatation process

·      Tinstone, Pyrolusite etc are purified by magnetic separation.

·      Calcination is the process of heating the ore below its melting point in absence of air to remove volatile impurities like, Arsenic etc..

·      Roasting is the process in which the ore is heated below its melting point in presence of air to oxidize the impurities. Eg: Carbon, Sulphar etc removed as their gaseous oxides.

·      Gangue is the impurity present in the ore

·      Generally, gangue is silica

·       Acidic flux is silica

·      Basic flux is limestone

·      Liquation is used to refine metals having a low melting point. Eg: lead and tin

·      The method used for refining metals containing volatile impurities is oxidation.

·      Distillation is used to refine volatile metals like mercury and zinc which contain non-volatile impurities.

·      Electro – refining is an economical and effective method for purifying metals Eg: Cu, Al, Pb

·      Flux is a chemical substance added to the ore during the extraction of metals by carbon reduction, which combines with the gangue and results in the formation of a fusible compound called slag.

·      In extraction of iron, calcium carbonates acts as a flux

·      Malachite is the mineral of copper

·      The most plentiful mineral is feldspar

·      Calamine is zinc carbonate

·      Monozite is an ore of thorium

·      Vermilion is made from the mercury ore, Cinnabar (Mercury-sulphide)

·      Gold and platinum occur exclusively in free state

·      Copper, mercury and silver occur partly in free state.

·      Most of the metals occur in the form of oxides, sulphides, carbonates, sulphates, chlorides and silicates.

·      Metals extracted from sea-water are magnesium and sodium

·      Metals generally accumulated in Living Organisms: Vanedium, Potassium

·      Most abundant metal present in developed animals: Calcium

·      Most abundant element present in our body: Oxygen

·      Most abundant compound present in animals: Water

·      Magnesium is concentrated in chloroplast

·      Major metals present in chloroplast are magnesium, manganese, copper and iron

·      Some elements behave chemically both as metals and non-metals. Such metals are called metalloids, Eg: Boron, Silicon, Germanium etc…

·      Major elements present in sea-water are chlorine, sodium, magnesium, Sulphur, calcium, potassium, carbon etc…

·      The halogens extracted from sea water are chlorine and bromine

·      The atmosphere mainly consists of nitrogen (78.09%) and oxygen (20.95%)

·      Lithosphere is the solid phase of the earth and is made of different types of rocks

·      Lithosphere is the major source of metals

·      Most abundant elements of earth’s crust are silicon and oxygen (about 75%)

·      Core is the central portion of earth

·      Metallic Core valuable metals like Manganese, Iron, Cobalt, Nickel, Copper, Platinum, Gold etc…

·      Sulphide Layer contains phosphorus, Sulphur, zinc, cadmium, tin, antimony, bismuth, lead, mercury etc…

·      Most abundant metal present in blood is Potassium

·      The elements which lose electrons in chemical reaction are called metals

·      A metal is an electropositive element which is hard, lustrous, malleable, ductile with tensile strength, and a good conductor of heat and electricity.

·      Metals form basic or amphoteric oxides

·      A non-metal is an electro negative element which occurs as solids, liquids and gases. They are generally poor conductors of heat and electricity.

·      Non-metallic solids are usually soft and brittle

·      Non-metals form acidic or neutral oxides

·      Silver is the best conductor of heat and electricity

·      Metals can be hammered into very thin sheets. This property is called malleability. Gold and silver are among the best malleable metals.

·      The property of metals capable of being drawn into wires is known as ductility. Gold is the most ductile of all the metals.

·      The metal, silver is an excellent reflector

·      Metals can be stretched to some degree without fracturing. This is a measure of their tensile strength. Some metals like tungsten have very high tensile strength

·      Mercury and gallium are metals which are liquids at room temperature.

·      The hardest metal is chromium

·      Heaviest metal occurring in nature is uranium

·      The first known super conductor is mercury

·      Metals like gold and copper are mostly found in old igneous rocks

·      The metal which is least affected by the exposure to the atmosphere is tin

·      Radium is used in the dials of clocks

·      Cobalt is useful in making rust resistant alloys

·      ‘King of metal’ is gold

·      Silver, platinum and gold are known as noble metals

·      Platinum metal occurs in its pure form in earth’s crust.

·      Iron rarely occurs in free state because it is very reactive

·       Mercury flows so easily and rapidly that it is sometime called quick silver

·      Metal present in the bath soap is potassium

·      Metals usually combine with oxygen to form basic oxides

·      The first metal to be used by man is copper

·      Some metals react with water. Sodium reacts violently even with cold water forming sodium hydroxide and hydrogen. Gold does not react even with steam

·      Some metals react with acid and replace the hydrogen atom in their molecules. Gold, copper, and silver are unaffected with hydrochloric acid.

·      Mercury is the metal having lowest melting point (-39ºC)

·      Wrought iron is the purest type of iron that contains least amount of carbon.

·      When iron rusts, its weight increases

·      Titanium is the metal of future

·      Sparkling and colour after the blast of fire cracker is due to the presence of strontium

·      Enamels are mixtures of silicates, backed on to iron or steel object

·      Iron coated with zinc is called galvanized iron and with tin is called tin-plate

·      Element extracted from monazite sand is thorium

·      White phosphorous is a strong poison

·      In high temperature thermometers, the space above the mercury column is filled with nitrogen to reduce its evaporation

·      White phosphorous is kept under water because it burns in air

·      Compounds of fluorine are used as cooling agents in refrigerators

·      Fluorinated polymer, Teflon, finds numerous uses as it is tough and fire-resistant.

·      Chlorine, either as liquid chlorine or chlorine water, is used for bleaching

·      Chlorine is used as an oxidizing agent.

·      Chloroform is an anesthetic, sodium hypochloride is an antiseptic, PVC is a plastic etc… are compounds of chlorine.

·      Rhombic Sulphur is the most stable form of Sulphur and exists at room temperature.

·      Element stored in kerosene to prevent oxidation is sodium

·      Commercially, aluminium is extracted from Bauxite through a combination of the Bayer’s process and the Heroult – Hall process.

·      Zinc is used in galvanization and dry cells

·      Zinc, as a reducing agent, is used in the manufacture of perfumes and synthetic drugs

·      Pig iron is used in the manufacturing of steel and cast iron

·      Phosphorous is used in the fertilizer industry

·      The element used to increase the hardness of rubber is Sulphur

·      The second most chemically active element is chlorine

·      Chlorine is used to kill germs in an indoor swimming pool

·      Silicon is used for making integrated chips used in computers, wax, greases and polish

·      In noble gases, radon is not present in air

·      Neon is used for making advertising signs

·      In a dry cell, zinc and carbon act as electrodes

·      The inert gas, which produces crimson glow when an electric discharge passes through it is, neon.

·      In the Halogen family, iodine exists as a solid and bromine as a liquid

·      The element present in the largest amount in rocks and minerals is silicon

·      Silver is the best conductor of heat

·      Lead is the poorest conductor of heat

·      Tungsten has the highest boiling point of all the elements. Hence, it is used for filaments in electric bulbs

·      Cesium is used in atomic clocks

·      Pure silicon is a semi-conductor and is used in electronic devices as the base for minute integrated circuits (ICs).

KERALA PSC / CHEMISTRY / METALS, NONMETALS & METALLURGY / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY