Which of the following substances can be liquefied by applying pressure at $25^{\circ} \mathrm{C}$ ? For those that cannot, describe the conditions under which they can be liquefied.

$$\begin{array}{lcl}\text { Substance } & \begin{array}{l}\text { Critical } \\ \text { Temperature }\end{array} & \begin{array}{l}\text { Critical } \\ \text { Pressure }\end{array} \\ \text { Sulfur dioxide, } \mathrm{SO}_2 & 158^{\circ} \mathrm{C} & 78 \mathrm{~atm} \\ \text { Acetylene, } \mathrm{C}_2 \mathrm{H}_2 & 36^{\circ} \mathrm{C} & 62 \mathrm{~atm} \\ \text { Methane, } \mathrm{CH}_4 & -82^{\circ} \mathrm{C} & 46 \mathrm{~atm} \\ \text { Carbon monoxide, } \mathrm{CO} & -140^{\circ} \mathrm{C} & 35 \mathrm{~atm}\end{array}$$

Anglers know that on hot summer days, the largest fish will be found in deep sinks in lake bottoms. Use the temperature dependence of the density of water and the temperature dependence of the oxygen solubility in water to explain why.

Use graph paper and sketch the phase diagram of oxygen, $\mathrm{O}_2$, from the following information: normal melting point, $-218^{\circ} \mathrm{C}$; normal boiling point, $-183^{\circ} \mathrm{C}$; triple point, $-219^{\circ} \mathrm{C}, 1.10 \mathrm{mmHg}$; critical point, $-118^{\circ} \mathrm{C}$, $50.1 \mathrm{~atm}$. Label each phase region on the diagram.

Showa here is the phase diagram for compound $\mathrm{Z}$. The triple point of $\mathrm{Z}$ is $-5.1^{\circ} \mathrm{C}$ at $3.3$ atm and the critical point is $51^{\circ} \mathrm{C}$ and $99.1 \mathrm{~atm}$.

a. What is the state of $\mathrm{Z}$ at position $\mathrm{A}$ ?

b. If we increase the temperature of the compound at position $\mathrm{A}$ to $60 \Omega \mathrm{C}$ while holding the pressure constant, what is the state of $\mathrm{Z}$ ?

c. If we take the compound starting under the conditions of part b and reduce the temperature to $20^{\circ} \mathrm{C}$ and increase the pressure to $65 \mathrm{~atm}$, what is the state of $\mathrm{Z}$ ?

d. Would it be possible to make the compound a solid by starting with the conditions of part $\mathrm{c}$ and increasing just the pressure?

The highest barrier that a projectile can clear is 13.5 m, when the projectile is launched at an angle of

$$15.0 ^ { \circ }$$

above the horizontal. What is the projectile's launch speed?

Carbon disulfide, $\mathrm{CS}_2$, is a volatile, flammable liquid. It has a vapor pressure of $400.0 \mathrm{mmHg}$ at $28.0^{\circ} \mathrm{C}$ and $760.0 \mathrm{mmHg}$ at $46.5^{\circ} \mathrm{C}$. What is the heat of vaporization of this substance?

White phosphorus, $P_4$, is normally a white, waxy solid melting at $44^{\circ} \mathrm{C}$ to a colorless liquid. The liquid has a vapor pressure of $400.0 \mathrm{mmHg}$ at $251.0^{\circ} \mathrm{C}$ and $760.0 \mathrm{mmHg}$ at $280.0^{\circ} \mathrm{C}$. What is the heat of vaporization of this substance?

Interphase in human cells takes about 23 hours. If the cell cycle is 24 hours, what percentage is interphase?

Methanol, $\mathrm{CH}_3 \mathrm{OH}$, a colorless, volatile liquid, was formerly known as wood alcohol. It boils at $65.0^{\circ} \mathrm{C}$ and has a heat of vaporization of $37.4 \mathrm{~kJ} / \mathrm{mol}$. What is its vapor pressure at $22.0^{\circ} \mathrm{C}$ ?

Why is the heat of fusion of a substance smaller than its heat of vaporization?

List the different intermolecular forces you would expect for each of the following compounds: a propanol, $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{OH}$ b (carbon dioxide see second model at left) c sulfur dioxide, $\mathrm{SO}_2$

Chloroform, $\mathrm{CHCl}_3$, a volatile liquid, was once used as an anesthetic but has been replaced by safer compounds. Chloroform boils at $61.7^{\circ} \mathrm{C}$ and has a heat of vaporization of $31.4 \mathrm{~kJ} / \mathrm{mol}$. What is its vapor pressure at $36.2^{\circ} \mathrm{C}$ ?

Steam at $100^{\circ} \mathrm{C}$ was passed into a flask containing $275 \mathrm{~g}$ of water at $21^{\circ} \mathrm{C}$, where the steam condensed. How many grams of steam must have condensed if the temperature of the water in the flask was raised to $83^{\circ} \mathrm{C}$ ? The heat of vaporization of water at $100^{\circ} \mathrm{C}$ is $40.7 \mathrm{~kJ} / \mathrm{mol}$ and the specific heat is $4.18 \mathrm{~J} /\left(\mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)$.

A quantity of ice at $0^{\circ} \mathrm{C}$ is added to $64.3 \mathrm{~g}$ of water in a glass at $55^{\circ} \mathrm{C}$. After the ice melted, the temperature of the water in the glass was $15^{\circ} \mathrm{C}$. How much ice was added? The heat of fusion of water is $6.01 \mathrm{~kJ} / \mathrm{mol}$ and the specific heat is $4.18 \mathrm{~J} /\left(\mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right)$.