How can the law of conservation of mass be applied?

2 Answers
Mar 2, 2015

The more you eat, the fatter you get!

In simple classical systems it's so obvious that it really doesn't really have a particular role at all.

However, once we realise that mass is equivalent to energy and so there can be transformations between the two, then it becomes much more interesting. When a uranium nucleus undergoes fission, we find that the masses of the products do not add up to the original mass; the difference is released as (kinetic) energy:

#E=\Delta m c^2#

An awful lot of energy!

Mar 3, 2015

The law of conservation of mass states that in a closed system, mass is neither created nor destroyed during a chemical or physical reaction. The law of conservation of mass is applied whenever you balance a chemical equation. It is also applicable to stoichiometry.