Question

Determine the phase changes that carbon dioxide undergoes as the pressure changes if the temperature is held at −50°C? If the temperature is held at −40°C? At 20°C?

Short answer

If the temperature is constant at$\left(-50^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$will be:

- gaseous if the pressure is approximately 10-700 kPa

- liquid if the pressure is approximately$700-200,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than$200,000\mathrm{k}\mathrm{P}\mathrm{a}$

If the temperature is constant at$\left(-40^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$will be:

- gaseous if the pressure is approximately 10-1000 kPa

- liquid if the pressure is approximately$1000-400,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than$400,000\mathrm{k}\mathrm{P}\mathrm{a}$

If the temperature is constant at$\left(20^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$will be:

- gaseous if the pressure is approximately$10-9000\mathrm{k}\mathrm{P}\mathrm{a}$

- liquid if the pressure is approximately$9000-900,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than$900,000\mathrm{k}\mathrm{P}\mathrm{a}$

Step-by-step solution

To determine the phase changes held at $-50^{{}^{\circ }}\mathrm{C}$

Let us determine the phase changes that $\mathrm{C}{\mathrm{O}}_2$undergoes as the pressure changes if the temperature is −50°C

Here we can see that, if the temperature is constant $\left(-50^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$ will be:

- gaseous if the pressure is approximately 10-700 kPa

- liquid if the pressure is approximately$700-200,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than $200,000\mathrm{k}\mathrm{P}\mathrm{a}$

To determine the phase changes held at $-40^{{}^{\circ }}\mathrm{C}$

If the temperature is constant $\left(-40^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$will be:

- gaseous if the pressure is approximately 10-1000 kPa

- liquid if the pressure is approximately$1000-400,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than $400,000\mathrm{k}\mathrm{P}\mathrm{a}$

To determine the phase changes held at $\left(20^{{}^{\circ }}\mathrm{C}\right)$

If the temperature is constant at$\left(20^{{}^{\circ }}\mathrm{C}\right),\mathrm{C}{\mathrm{O}}_2$will be:

-gaseous if the pressure is approximately 10-9000 kPa

-liquid if the pressure is approximately$9000-900,000\mathrm{k}\mathrm{P}\mathrm{a}$

-solid if the pressure is higher than $900,000\mathrm{k}\mathrm{P}\mathrm{a}$