Chemical Reactions Chemistry Notes
Chemical Reactions :
→ On the basis of rate, reactions can be grouped into following classes : 1. lonic or Instantaneous Reactions : These reactions take place between ions so they proceed very rapidly. Their rate is very high due to which it is very difficult to measure the rate of such reaction. These reactions are called instantaneous reactions as they completed rapidly.
→ Very Slow Reactions : These reactions take place between molecules. So, these are molecular reactions. The rate of such reactions is so slow that it may be completed in months or years. No observable or measurable change takes place in these reactions.
→ These reactions are not suitable for the study under chemical kinetics. Example : Rusting of iron in presence of air and moisture, the rate of reaction for the formation of water by combination of hydrogen and oxygen in the absence of catalyst.
→ Molecular or Slow Reactions : Reactions which take place between molecules are called molecular reactions. These reactions take more time as compared to very slow reaction for completion so their rates can be determined easily by chemical kineties. Example Formation of ester by the reaction between acid and alcohol