Law of conservation of mass

Some basic concepts of chemistry  #04

Laws of  chemical combination.

1. Law of conservation of mass :  It states  that,   " Matter can neither be created nor destroyed as a result of any chemical or physical  change "
   

  

        but this law  is not absolutely true,  there is limitations of the law of conservation  of mass.

Limitations :  according to modern theory of Radiation, the thing is  mass and energy are inter convertible  according to einstein equations (E=mc²).

         A  chemical reaction which is accompanied by an emission of energy  usually in the form of heat, will be attend with loss of mass=E/c².  As c is very large, the loss of mass becomes insignificantly small. thus the law of conservation of mass holds good for ordinary chemical reactions.  but in nuclear fission/fusion enormous amounts of energy  is liberated by the conservation  of small amount of matter. 

• Modified  Law of conservation  of mass:  It can be stated as " In any reaction, the total amount of mass and energy remains constant "