Chapter 13, Problem 61P

a.

To determine

To explain: The phases in which ${\text{CO}}_2$ exist.

Answer to Problem 61P

  ${\text{CO}}_2$ either exists in solid form or vapor form at atmospheric pressure.

Explanation of Solution

Given:

The phase diagram of carbon dioxide is shown below.

  

From the graph, it is observed that at atmospheric pressure, ${\text{CO}}_2$ can exist either in solid form or in vapor form. Liquid carbon-dioxide will not exist at atmospheric pressure.

Conclusion:

Therefore, ${\text{CO}}_2$ either exists in solid form or vapor form at atmospheric pressure.

b.

To determine

To calculate: The range of pressure and temperatures can ${\text{CO}}_{\text{2}}$ be a liquid.

Answer to Problem 61P

The pressure should be above $\text{5}.\text{1}\text{atm}$ and the temperature range is $-56.6°\text{C<}\mathrm{T}<31.1\text{°C}$

Explanation of Solution

Given:

The phase diagram of carbon dioxide is shown below.

  

Liquid ${\text{CO}}_2$ is a type of liquid which is formed from gaseous ${\text{CO}}_2$ that is highly compressed and cooled.But under atmospheric conditions, it does not form. From the graph, it is observed that liquid carbon-dioxide will exists after triple point. It means for the temperature that is under $31.1\text{°C}$ (temperature of a critical point) and above $-56.6°\text{C}$ (temperature of a triple point) and when the pressure is above $\text{5}.\text{1 atm}$ .

Conclusion:

The pressure should be above $\text{5}.\text{1}\text{atm}$ and the temperature range is $-56.6°\text{C<}\mathrm{T}<31.1\text{°C}$