Physical Chemistry Study Packet Flashcards

Practice flashcards covering physical constants, intramolecular forces, colligative properties, vapor pressure calculations, and phase diagrams.

What are the two provided values for the gas constant $R$?

$8.314 \, L \times kPa/mole-K$ and $0.008314 \, kJ/mole-K$

What is the van’t Hoff factor ($i$) for Magnesium Chloride ($MgCl_2$)?

$$2.7$$

In terms of physical properties, what is the definition of adhesion?

Attractive forces between dissimilar atoms

How does increasing intramolecular forces affect the vapor pressure of a substance?

It decreases

What is the effect of increasing intramolecular forces on viscosity and surface tension?

Both viscosity and surface tension increase

According to the transcript, what causes capillary action?

A difference in adhesive and cohesive forces

What are the freezing point ($K_f$) and boiling point ($K_b$) constants for Cyclohexane?

$K_f = 20.0 \, ^{\circ}C/m$ and $K_b = 2.79 \, ^{\circ}C/m$

What is the vapor pressure of Ethanol at $25 \, ^{\circ}C$?

$$7.87 \, kPa$$

What is the freezing point change ($\Delta T_f$) when $2.00 \, g$ of $MgSO_4$ are dissolved in $0.300 \, kg$ of ethanol?

$$0.143$$

What is the theoretical vapor pressure of a Methanol-Ethanol mixture that is $50.0 \, \%$ Methanol and balance Ethanol at $25 \, ^{\circ}C$?

$$12.4 \, kPa$$

What is the osmotic pressure of $10.0 \, g$ of $NaCl$ dissolved in $0.750 \, L$ of water at $25 \, ^{\circ}C$?

$$1070 \, kPa$$

Using the Clausius-Clapeyron equation data, if the vapor pressure is $12.5 \, torr$ at $T = 25 \, ^{\circ}C$, what is the vapor pressure at $65 \, ^{\circ}C$ given $\Delta H_{vap} = 23 \, kJ/mole$?

$$37.5 \, torr$$

What is the calculated $\Delta H_{vap}$ if the vapor pressure is $3.4 \, torr$ at $T = 11.6 \, ^{\circ}C$ and $28.8 \, torr$ at $54.9 \, ^{\circ}C$?

$$38.4 \, kJ/mole$$

Describe the phase transitions of water compressed from $22,100 \, kPa$ to $70 \, kPa$ at $0 \, ^{\circ}C$ and then heated to $200 \, ^{\circ}C$.

The water starts as liquid, transitions to a solid, then melts back to a liquid upon heating, and finally vaporizes into water vapor.

Describe the sequence for Copper oxide heated at $1 \, torr$ from $600 \, ^{\circ}C$ to $1300 \, ^{\circ}C$ followed by isothermal decompression to $10^{-4} \, torr$.

Copper starts as $CuO$, transitions to $Cu_2O$, then becomes liquid $Cu_2O$. Upon decompression, the $Cu_2O$ forms liquid copper.