Question

You are trying to boil water while camping in the Colorado Rockies. The surrounding barometric pressure is 0.9 bar, and the water is currently boiling. Using Gibb's phase rule, the system is O Over Specified O Under Specified O Perfectly Specified

Answer 1

Perfectly Specified

Step-by-step explanation:

Given,

Pressure = P = 0.9 atm

and the Boiling point = T

Number of phases P = 1

Number of components C = 1

According to Gibb's phase rule ,

F = C - P + 2

If

• F = 0, the system is perfectly specified

• F > 0, the system is under specified

• F < 0 the system is over specified

At P = 0.9 atm, boiling point is T i.e. Fixed equal to 96.7 °C (from steam table)

P is independent variable and T is dependent variable (depends on the value of P ).

In this case only two variables are required to fix the system pressure and temperature.

In the given problem, pressure is fixed so the temperature is also fixed. There is no requirement of any other variable.

Therefore degree of freedom,

F = 0

The system is perfectly specified.