Explain why we cannot use osmotic pressure to determine both molar mass and percent ionization for an unknown monoprotic acid.

Both $\mathrm{NaCl}$ and $\mathrm{CaCl}_2$ are used to melt ice on roads and sidewalks in winter. What advantages do these substances have over sucrose or urea in lowering the freezing point of water?

At $25^{\circ} \mathrm{C}$, the vapor pressure of pure water is $23.76 \mathrm{mmHg}$ and that of seawater is $22.98 \mathrm{mmHg}$. Assuming that seawater contains only $\mathrm{NaCl}$, estimate its molal concentration.

What are the normal freezing points and boiling points of the following solution: $15.4 \mathrm{~g}$ of urea in $66.7 \mathrm{~mL}$ of water?

What are the normal freezing points and boiling points of the following solution: $21.2 \mathrm{~g} \mathrm{NaCl}$ in $135 \mathrm{~mL}$ of water

Which of the following aqueous solutions has the higher freezing point: $0.35 \mathrm{~m} \mathrm{CaCl}{ }_2$ or $0.90 m$ urea? Explain. Assume complete dissociation.

Which of the following aqueous solutions has the higher boiling point: $0.35 \mathrm{~m} \mathrm{CaCl}{ }_2$ or $0.90 m$ urea? Explain. Assume complete dissociation.

What is the osmotic pressure (in atm) of a $1.57 M$ aqueous solution of urea $\left[\left(\mathrm{NH}_2\right)_2 \mathrm{CO}\right]$ at $27.0^{\circ} \mathrm{C}$ ?

A solution is prepared by condensing $4.00 \mathrm{~L}$ of a gas, measured at $27^{\circ} \mathrm{C}$ and $748 \mathrm{mmHg}$ pressure, into $75.0 \mathrm{~g}$ of benzene. Calculate the freezing point of this solution.

How many liters of the antifreeze ethylene glycol $\left[\mathrm{CH}_2(\mathrm{OH}) \mathrm{CH}_2(\mathrm{OH})\right]$ would you add to a car radiator containing $6.50 \mathrm{~L}$ of water if the coldest winter temperature in your area is $-20^{\circ} \mathrm{C}$ ? Calculate the boiling point of this water-ethylene glycol mixture. (The density of ethylene glycol is $1.11 \mathrm{~g} / \mathrm{mL}$.)

An aqueous solution contains the amino acid glycine $\left(\mathrm{NH}_2 \mathrm{CH}_2 \mathrm{COOH}\right)$. Assuming that the acid does not ionize in water, calculate the molality of the solution if it freezes at $-1.1^{\circ} \mathrm{C}$.

What are the boiling point and freezing point of a $3.12 \mathrm{~m}$ solution of naphthalene in benzene? (The boiling point and freezing point of benzene are $80.1^{\circ} \mathrm{C}$ and $5.5^{\circ} \mathrm{C}$, respectively.)

How many grams of urea $\left[\left(\mathrm{NH}_2\right)_2 \mathrm{CO}\right]$ must be added to $658 \mathrm{~g}$ of water to give a solution with a vapor pressure $2.50 \mathrm{mmHg}$ lower than that of pure water at $30^{\circ} \mathrm{C}$ ? (The vapor pressure of water at $30^{\circ} \mathrm{C}$ is $31.8 \mathrm{mmHg}$.)

The vapor pressure of ethanol $\left(\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}\right)$ at $20^{\circ} \mathrm{C}$ is $44 \mathrm{mmHg}$, and the vapor pressure of methanol $\left(\mathrm{CH}_3 \mathrm{OH}\right)$ at the same temperature is $94 \mathrm{mmHg}$. A mixture of $30.0 \mathrm{~g}$ of methanol and $45.0 \mathrm{~g}$ of ethanol is prepared (and can be assumed to behave as an ideal solution). Suggest a method for separating the two components of the solution.