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...

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 ..

It has enabled us to explain the laws of chemical combination. Dalton was the first person to recognize a workable distinction between the ultimate particle of an element (atom) and that of a compound (molecule)..

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..

Although the long form of the period table has been able to help in systematic studying the elements to a great extent, it has some minor defects: Hydrogen resembles both the alkali metals and halogens. But it has been placed with the alkalis. The lanthanides and actinides have not been place..

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..

Merits: 1. Mean deviation is easy to calculate. This measure is simple to understand. 2. This can be calculated from any average. 3. It is less affected by extreme observations. Demerits: 1. This is mathematically incomplete because it ign..

Merits: s is based on every item of the data. s takes care of both positive and negative deviation. Demerits: s is some what not easy to understand. The extreme values unduly affect s..

Merits:..

Merits: - Mean deviation is easy to calculate. This measure is simple to understand. This can be calculated from any average. Its value is based upon all the (observations) items of the data. It is less affected by extreme observations. It gives us an idea about how the items are situated..