Railway Recruitment Board Exam For ASM SOLVED QUESTIONS
(1) 1959(2) 1965(3) 1976(4) 1982 Ans. (3) (l) heat is absorbed(2) heat is released(3) heat remains unchanged(4) None of these Ans. (2) (1) Xenon(2) Argon(3) Helium(4) Radon Ans. (4) (1)…
Momentum – Force and Laws of Motion
What is Momentum It is the quantity of motion of a moving body & may be defined as a product of mass and velocity. Its unit is ‘kilogram meter per…
Balancing Chemical Equations for beginners
Balancing a chemical equation involves a certain amount of trial and error. In general, however, you should follow these steps: Count each type of atom in reactants and products. Does…
Acids and Bases and Salts – Introduction
Acids and bases react with one another to yield two products: water, and an ionic compound known as a salt. This kind of reaction is called a neutralization reaction. All alkalis are…
ORGANIC CHEMISTRY – SOME BASIC PRINCIPLES AND TECHNIQUES
SOME BASIC PRINCIPLES AND TECHNIQUES The element carbon has the unique property called catenation due to which it forms covalent bonds with other carbon atoms. Berzilius, a Swedish chemist proposed…
Aromaticity
Benzene was considered as parent ‘aromatic’ compound. Now, the name is applied to all the ring systems whether or not having benzene ring, possessing following characteristics. (i) Planarity (ii) Complete…
CARCINOGENICITY AND TOXICITY
Benzene and polynuclear hydrocarbons containing more than two benzene rings fused together are toxic and said to possess cancer producing (carcinogenic) property. Such polynuclear hydrocarbons are formed on incomplete combustion…
Benzene – (Hydrocarbons)
Ethyne on passing through red hot iron tube at 873K undergoes cyclic polymerization. Three molecules polymerise to form benzene, which is the starting molecule for the preparation of derivatives of…