Unary phase diagram consists of only one substance.

Given F = 0
Then p = c + 1, c = 1
.: P = 2.

The eutectic temperature for Fe-C system is 1146°C. The eutectic reaction is a reaction that transforms one liquid phase into two solid phases on cooling.

Eutectic reaction is reaction in which Liquid phase directly converts into two different solid phases at a constant temperature known as eutectic temperature.

We can solve above question by using Gibb’s phase rule. When given values are put in equation value is obtained to be zero which makes reaction invariant.

Urinary phase diagram is a phase diagram of a single component over a range of temperature-pressure. It may consist of one or more phases but its chemical composition remains same.

In Fe-C system, re is a eutectoid point at 0.8wt% C, and temp of 723°C. The phase just above eutectoid temperature for carbon steels is known as austeniteor gamma.

Let c be Carbon content. Applying lever rule
0.091 = (6.67 ? c)/(6.67 ? 0.025)
c = 0.1% C.

In figure pure substances exists at 1, 3, 5 out of which 1 is given solid so 5 is pure gas.

We can solve above question by using Gibb’s phase rule. When given values are put in equation value is obtained to be two which makes reaction bivariant.