Question

It is well known that water freezes at 0°C at atmospheric pressure. The mixture of liquid water and ice at 0°C is said to be at stable equilibrium since it cannot undergo any changes when it is isolated from its surroundings. However, when water is free of impurities and the inner surfaces of the container are smooth, the temperature of water can be lowered to 22°C or even lower without any formation of ice at atmospheric pressure. But at that state even a small disturbance can initiate the formation of ice abruptly, and the water temperature stabilizes at 0°C following this sudden change. The water at 22°C is said to be in a metastable state. Write an essay on metastable states and discuss how they differ from stable equilibrium states.

 

 

Answer 1

Generally a metastable state is defined from the exited state of an atom, nucleus that have longer lifetime than ordinary exited state and that generally have shorter lifetime than the lowest..

 

Therefore a metastable state is considered to be a kind of stable intermediate stage of system of energy which is lost in discrete amounts...

 

Metastable state often loose their stored energy by collision with other atoms before they radiate it .

 

In a criteria a meta stable state looses its nuclei by reasons radioactive decay by gamma radiation etc..

 

Now in a water state system coming from above example as water being in metastable state is super cooling, when liquid water remains liqiud when cooled below the freezing point.

 

As a pure liquid reaches its metastable equilibrium state with its substrated water across an appropriate membrane..

 

The stability is depicted in figure as well.

 

HOW METASTABLE STATE DIFFER FROM STABLE EQIULIBRIUM STATES

To know the difference first know the definitions of equilibrium and stable equilibrium state..

as equilibrium states having only two constraints have the lowest energy for a given conditions..

which are stable equilibrium states...

whereas equilibrium states having more than two constraints are called as meta stable equilibrium state..

whereas equilibrium states having more than two constraints are called as meta stable equilibrium state..