Chapter 12, Problem 33PS

(a)

Interpretation Introduction

Interpretation:

Density of the liquid carbon dioxide is greater or less than solid carbon dioxide has to be identified.

Concept introduction:

All three phases of ${\text{CO}}_{\text{2}}$ exist simultaneously at the triple point.

${\text{CO}}_{\text{2}}$ forms a supercritical fluid at temperatures less than $31{}^{\text{o}}\text{C}$.

${\text{CO}}_{\text{2}}$ is a gas under normal conditions of temperature and pressure.

${\text{CO}}_{\text{2}}$ exists as a solid when the pressure is 4 atm and the temperature is more than $\text{-56}\text{.7}{}^{\text{o}}\text{C}$.

Answer to Problem 33PS

The density of liquid ${\text{CO}}_{\text{2}}$ is less than that of solid ${\text{CO}}_{\text{2}}$

Explanation of Solution

The phase diagram of ${\text{CO}}_{\text{2}}$ is given below,

            Figure 1

When seeing the phase diagram of ${\text{CO}}_{\text{2}}$, the density of liquid ${\text{CO}}_{\text{2}}$ is less than that of solid ${\text{CO}}_{\text{2}}$ hence the newly formed ${\text{CO}}_{\text{2}}$ is settled down to the bottom in a container of liquid ${\text{CO}}_{\text{2}}$.

(b)

Interpretation Introduction

Interpretation:

Phase at which carbon dioxide at 5tm and $0^{0}C$ has to be determined.

Concept introduction:

All three phases of ${\text{CO}}_{\text{2}}$ exist simultaneously at the triple point.

${\text{CO}}_{\text{2}}$ forms a supercritical fluid at temperatures less than $31{}^{\text{o}}\text{C}$.

${\text{CO}}_{\text{2}}$ is a gas under normal conditions of temperature and pressure.

${\text{CO}}_{\text{2}}$ exists as a solid when the pressure is 4 atm and the temperature is more than $\text{-56}\text{.7}{}^{\text{o}}\text{C}$.

Answer to Problem 33PS

${\text{CO}}_{\text{2}}$ is gas at 5 atm and $0{}^{\text{o}}\text{C}$

Explanation of Solution

The phase diagram of ${\text{CO}}_{\text{2}}$ is given below,

            Figure 1

When seeing the phase diagram of ${\text{CO}}_{\text{2}}$, the density of liquid ${\text{CO}}_{\text{2}}$ is less than that of solid ${\text{CO}}_{\text{2}}$ hence the newly formed ${\text{CO}}_{\text{2}}$ is settled down to the bottom in a container of liquid ${\text{CO}}_{\text{2}}$.

In the phase diagram of ${\text{CO}}_{\text{2}}$, the triple point of ${\text{CO}}_{\text{2}}$ occurs at 5.10 atm and $\text{-56}\text{.7}{}^{\text{o}}\text{C}$, therefore ${\text{CO}}_{\text{2}}$ is not liquid when the pressure is less than 5 atm. Therefore, ${\text{CO}}_{\text{2}}$ is gas at 5 atm and $0{}^{\text{o}}\text{C}$

(b)

Interpretation Introduction

Interpretation:

Carbon dioxide can be liquefied at ${45}^{0}C$ or not has to be determined.

Concept introduction:

All three phases of ${\text{CO}}_{\text{2}}$ exist simultaneously at the triple point.

${\text{CO}}_{\text{2}}$ forms a supercritical fluid at temperatures less than $31{}^{\text{o}}\text{C}$.

${\text{CO}}_{\text{2}}$ is a gas under normal conditions of temperature and pressure.

${\text{CO}}_{\text{2}}$ exists as a solid when the pressure is 4 atm and the temperature is more than $\text{-56}\text{.7}{}^{\text{o}}\text{C}$.

Answer to Problem 33PS

${\text{CO}}_{\text{2}}$ forms a supercritical fluid at temperatures less than $31{}^{\text{o}}\text{C}$. Therefore ${\text{CO}}_{\text{2}}$ cannot liquefied at $45{}^{\text{o}}\text{C}$

Explanation of Solution

The phase diagram of ${\text{CO}}_{\text{2}}$ is given below,

            Figure 1

When seeing the phase diagram of ${\text{CO}}_{\text{2}}$, the density of liquid ${\text{CO}}_{\text{2}}$ is less than that of solid ${\text{CO}}_{\text{2}}$ hence the newly formed ${\text{CO}}_{\text{2}}$ is settled down to the bottom in a container of liquid ${\text{CO}}_{\text{2}}$.

In the phase diagram of ${\text{CO}}_{\text{2}}$, ${\text{CO}}_{\text{2}}$ forms a supercritical fluid at temperatures less than $31{}^{\text{o}}\text{C}$. Therefore ${\text{CO}}_{\text{2}}$ cannot liquefied at $45{}^{\text{o}}\text{C}$