notes on merits and demerits of chemistry

In spite of the above advantages, Mendeleev's periodic table suffered defects as follows: The position of hydrogen was not correctly defined. It was placed in group I although it resembles both the group I elements - the alkali metals and the group VII elements-the halogens, in their properties...

Writing HCl 2 is incorrect since it would not be the same compound as HCl. It is observed that hydrogen is also balanced. Finally to check the correctness of the balanced chemical equation, count the atoms of each element on both sides of equation. Left Side Right Side Mg 1 1 ..

The raw materials used and the principle involved are common to both the types of biogas plant..

Residual oil is that component of petroleum, which is collected first at the bottom of the tower. It has a boiling range of over 400 o C. It can be further distilled separately to obtain lubricating oil, paraffin wax, asphalt etc. Most fractions of petroleum are fuels. Asphalt, lubricating ..

Although the SI unit of temperature is Kelvin, Celsius scale ( o C) is commonly used. K= o C + 273.15. Similarly Angstrom () is the commonly used unit but nanometer or picometer is the SI unit.1nm = 10 -9 m, 1pm = 10 -12 ..

Biopolymers include various biomolecules such as carbohydrates, proteins et..

In the E isomer above one can't determine whether they are cis or trans. The isomer is in that form because according to priority assignments, the chloro and the ethyl substituents are on opposite sides of the molecul..

Mendeleev's periodic table was one of the greatest achievements in Chemistry with some of its important contributions as follows: As the arrangements are classified into groups, it was very useful in studying and remembering the properties of a large number of elements in a systematic ..

This process gives soda of much higher purity (99.5%). It is less expensive as the raw materials are cheap and CO 2 and NH 3 are recovered to be used again. Calcium chloride is the only waste is the solution and so no pollution problems. Formation of sodium bicarbonate as an intermedia..

This classification is based on the most fundamental property of the elements - the atomic number, so it is more accurate. With the atomic number as the basis of this classification, the position of isotopes in one place is justified. The systematic grouping of elements into the four blocks..