Showing posts with label Chemistry. Show all posts
Showing posts with label Chemistry. Show all posts

Jul 14, 2012

Dalton's Atomic Theory and Stoichiometry

Stoichiometry is the branch of chemistry which deals with the weight relationship in chemical reaction and weight relationship that prevails in a chemical compound.
Dalton’s atomic Theory
In 1808, John Dalton gave his atomic theory and successfully explained the laws of chemical combinations. Before that philosophers were puzzled about the nature of matter. This theory is the milestone in the development of modern chemistry. The original statement given by Dalton has undergone expansion, modifications and clarification to a great extent. The main postulates of this theory are as follows.

Jul 11, 2012

Valence Shell Electron Pair Repulsion Theory

This is a theory to predict the shapes of molecules. It was given by Sidwick and Powel in 1940. VSEPR theory stands for Valence Shell Electron Pair Repulsion theory. This theory is based on the idea that electron pairs try to be as far apart as possible to minimize the repulsion. The main assumptions of VSEPR theory are as follows:

Dec 14, 2011

Acid Rain and Greenhouse Effect

What is Acid Rain? How is it Caused?

Generally, acid rain means the rain of water containing excessive amount of acids.
Oxides of Slulphur, Carbon, and Nitrogen are major gaseous pollutant of air. These oxides are produced mainly by the combustion of fossil fuels, power plants, automobile exhaust, domestic fire etc. These oxides make layers and remains in the atmosphere. During rain, they react with water to form acids like Sulphuric acid, Nitric acid, Nitrous acid which then comes to the earth surface as acid rain or remain in the atmosphere in clouds or fogs.

Nov 17, 2011

Chemistries of Some Important Compounds | Chemistry-XII

Hello all,
No need to say that, this was really a very long break. We are happy to announce that we are back again. Hope you enjoyed your holidays. Now it’s time to wake up and get back to the work. Yeah, we are already on our way typing notes for you. I am sure that you are curious about the upcoming notes. So this post is just to erase a little of your curiosity.