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

 

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

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

·      Kevlar is a material for making bullet proof dresses

·      The oil in water is an example of suspension

·      Catalyst in a chemical reaction generally helps to accelerate the reaction

·      The main use of salt in the diet is to produce hydrochloric acid to digest the food

·      Chlorination means the addition of a small quantity of chlorine in water as a germicide

·      Hydrogen has the same atomic number and mass number

·      The ultimate source of nitrogen is the atmosphere but, plants and animals cannot assimilate atmospheric nitrogen directly

·      The animals get their nitrogen supply in the form of proteins from plants which in turn get their nitrogen supply from the soil in the form of nitrates.

·      Ammonia (NH₃) is a compound of nitrogen. It can be manufactured by combining nitrogen and hydrogen at low temperature under high pressure

·      Air pollution caused by automobiles can be reduced by using lead free petrol and design alternations in automobiles

·      Carbon monoxide (CO) is most carcinogenic in nature

·      Normal Oxygen (O₂) and Ozone (O₃) are allotropes of oxygen

·      Diamond, corundum and topaz are all very hard. A scale called Moh’s scale is used to indicate the degree of hardness of minerals

·      Purest form of iron is wrought iron

·      Pure water is obtained from sea water by the process of distillation

·      Helium is preferred to hydrogen in air balloons because it does not form an explosive mixture with air

·      Oils and fats are naturally occurring compounds that belonging to lipids

·      Hydrogenation (hardening of oil) is a process of converting an oil into a fat example vegetable ghee. In which hydrogen gas is passed through the oil in the presence of nickel catalyst.

·      Batho chromic groups cause displacement to longer wavelengths, while hypsochromic groups cause displacement to the shorter wavelengths.

·      Caprolactum obtained from cyclohexane

·      Dichloro Diphenyl Trichloro ethane (DDT), Benzene Hexa chloride ie, BHC (Gammeexane) are organic insecticides

·      Sulpha drugs are used as antibacterial

·      Turpentine oil is commercially obtained from pine tree

·      CFCs are also known as Ozone Depleting Substances (ODS) for it causes depletion of the ozone layer

·      Freon (Dichloro difluoro Methane) it is used as refrigerant

·      Ozone depleting substance include, Bromine containing compounds halons and HBFCs (hydrobromo fluro carbons) both used in fire extinguishers. Methyl bromide (pesticide). Each bromine atom destroys hundreds of times more zone molecules than does a chlorine atom.

·      Alkaline solution of copper sulphate and sodium citrate is called Benedict solution, which is used to detect glucose in urine

·      The lead pencils contain graphite and clay

·      Osmosis: It is the phenomenon of flow of pure solvent from a less concentrated solution to a more concentrated solution through a semi permeable membrane.

·      Buffers: A solution which resist change in pH by the addition of small amount of acid or base.

·      Sorenson (1909) introduced the term pH to express H+ ion concentration

·      pH of important Biological fluids

Blood                     7.35 – 7.45

Tear                       7.2 – 7.4

Saliva                     6.4 – 7

Gastric Juice          1.5 – 3.0

·      Isomerism: The compounds possessing identical molecular formulae but different structures are referred to as isomers. The phenomenon of existence of isomers is called isomerism.

 

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