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Monday, 5 October 2026

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CHLORINE / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CHLORINE / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· Chlorine is a member of halogen group

· Other halogens are: Fluorine, Bromine, Iodine, Astatine, of which Astatine is a radioactive element

· It is a poisonous gas

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

· Chlorine is used for sterilizing drinking water

· Bleaching powder is used as a bleaching agent

· Sodium hypochlorite is used as an antiseptic

· Chloroform is used as an anesthetic

· Carbon tetrachloride is used as a solvent

· Poly-vinyl-chloride is an important plastic

· Chlorine is used as an oxidizing agent

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CHLORINE / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / AMMONIA / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / AMMONIA / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· Ammonia is a compound of nitrogen and hydrogen with the formula NH₃

· It is an intermediate gaseous product in the decaying process of dead organic matter

· Industrially, it is manufactured through Haber’s Process

· It is a colourless gas with a strong pungent smell and slightly alkaline taste

· It is lighter than air

· Highly soluble in water

· It is used in the manufacture of fertilizers, nitric acid and sodium carbonate

· Nylon, rayon, plastics, dyes and explosives are all made from ammonia

· Ammonia can be liquefied easily and liquid ammonia is highly volatile

· Ammonia emulsifies fats and grease so that they can be removed without leaving any residue. Thus, it acts as a cleaning agent.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / AMMONIA / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CALCIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CALCIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· Calcium phosphate is the main constituent of bones and teeth, calcium carbonate is the constituent of protective shells of marine animals.

· Main compounds of calcium are calcium oxide (quick lime), Calcium Carbonate (lime stone, marble, chalk, Dolomite, Gypsum plaster of Paris, Calcium hydroxide (slaked lime)

· Suspension of slaked lime in water is called milk of lime.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CALCIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / SODIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / SODIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· It is found in the form of sodium Chloride, Sodium Nitrate (Chile Salt Peter), Sodium Sulphate (Glauber’s Salt) and borax (Sodium tetraborate)

· Sodium Carbonate or Washing Soda and Sodium Bi Carbonate or Baking Soda are the main compounds.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / SODIUM / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / NITROGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / NITROGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· In the free states, nitrogen constitutes nearly 80% of the air.

· Nitrogen is the largest single constituent of the Earth’s atmosphere (78.082% by volume of dry air, 75.3% by weight in dry air)

· Atomic number -7

· Nitrogen obtained from air through fractional distillation is called Atmospheric Nitrogen

· Nitrogen obtained from nitrogenous compounds is called Chemical nitrogen

· Nitrogen is neither combustible nor a supporter of combustion.

· Nitrogen is a non-poisonous gas. Nevertheless animals die in an atmosphere of nitrogen for want of oxygen they need to breathe

· The Nitrogen Cycle: The sum total of the transformations undergone by nitrogen and nitrogenous compounds in nature in relation to the living organisms.

· Many industrially important compounds, such as ammonia, nitric acid, organic nitrates (propellants and explosives) and cyanides, contain nitrogen

· The element nitrogen was discovered by Scottish physician Daniel Rutherford in 1772

· It is a constituent element of amino acids and thus of proteins, and of nucleic acids (DNA and RNA)

· It resides in the chemical structure of almost all neurotransmitters, and is a defining component of alkaloids, biological molecules produced by many organisms

· It is created by fusion processes in stars, and is estimated to be the 7^th most abundant chemical element by mass in the universe.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / NITROGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CARBON / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CARBON / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· Carbon is first element of group 14 of periodic table.

· It has maximum tendency of catenation (self-linking property) in comparison to any other element in the periodic table

· It ranks 17^th in order of abundance in earth crust

· Naturally occurring carbon contains 2 stable isotopes. ¹²C and ¹³C along with traces of ¹⁴C

· The crystalline allotropes of carbon are diamond, Graphite, fullerene

· Amorphous allotropes of carbon are coal, charcoal and lamp black.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / CARBON / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / OXYGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / OXYGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY

· Oxygen is a colourless, tasteless and odourless gas

· Oxygen does not burn but helps things to burn

· Atomic number is 8

· It is a member of the chalcogen group on the periodic table

· Oxygen is the third most abundant element in the universe by mass after hydrogen and helium

· All major classes of structural molecules in living organisms, such as proteins, carbohydrates, and fats, contain oxygen

· Uses of oxygen include the production of steel, plastics and textiles; rocket propellant; oxygen therapy; and life support in aircraft, submarines, spaceflight and diving

· Smelting of iron ore into steel consumes 55% of commercially produced oxygen.

KERALA PSC / CHEMISTRY / IMPORTANT ELEMENTS / OXYGEN / NOTES / OBJECTIVE QUESTIONS / STUDY MATERIALS / GENERAL KNOWLEDGE / KERALA PSC PRELIMINARY