In a binary system, what is the maximum number of phases that can co-exist under the equilibrium conditions? One a b Two Three C d Four

D) Four

Explanation:

Using phase rule,

F = C - P + 2

where,

C is the number of components in the system. For example, for binary systems, C=2

P indicates the number of phase of the component. It is defined as homogeneous chemical composition of the substance. Thus, two immiscible liquids with definite boundaries form 2 phases.

F is the number of variables. For example, variables like temperature, pressure, mole fraction, etc.

Thus, using this

C = 2

For P to be maximum, F has to be 0. This is the condition when all the variable of the binary system is known.

So,

F = C - P + 2

0 = 2 - P + 2

P = 4