Chapter 13, Problem 1SAQ

Determine what state this substance is in at 1 atm and 298 K by referring to its phase diagram.

a) Solid
b) Li quid
c) Gas
d) All three states in equilibrium

Interpretation Introduction

Interpretation: The state of a substance at $\text{1}\text{atm}$ and $\text{298}\text{K}$ for the given phase diagram should be determined.

Concept introduction: A phase diagram represents what phases exist at equilibrium and the phase transformation that one can expect on changing one of the parameters of the system $\left(\text{P,T,Composition}\right)$ or both. It is graphical representation of phase change with temperature and pressure.

In order to determine the phase of a substance, draw a horizontal line corresponding to given pressure and a vertical line corresponding to given temperature. The point of intersection of these two horizontal and vertical lines gives the idea in which phase the given material exist.

To determine: what state this substance is at $1$

$\text{atm}$ and $298\text{ K}$ by referring to its phase diagram

  $\left(a\right)$ Solid

  $\left(b\right)$ Liquid

  $\left(c\right)$ Gas

  $\left(d\right)$ All three state in equilibrium.

Answer to Problem 1SAQ

Solution: The phase of this substance at $1$

$\text{atm}$ and $298\text{ K}$ is gas.

Explanation of Solution

Given, Pressure $=1$

  $\text{atm}$

Temperature $=298\text{ K}$

And following phase diagram

Draw horizontal and vertical line corresponding to given temperature and pressure.

From above diagram it becomes clear that point of intersection is in gas phase so this substance at $1$

$\text{atm}$ and $\text{298 K}$ exists in gas.

Conclusion

Phase of any substance is function of both temperature and pressure.