$$m = \frac{\text{moles of solute}}{\text{kilograms of solvent}}$$

Question 1

Which statement best explains why water has a solid-liquid boundary line with a negative slope in its phase diagram?

Accepted Answer

Because the solid phase of water is less dense than the liquid phase.

Question 2

Which of the following best describes a colloid?

Accepted Answer

A homogeneous mixture with particles between 2 and 500 nm in diameter.

Question 3

A solution is prepared by dissolving 12.5 g of glucose in 95.8 g of water. What is the mass percent of glucose in the solution?

Accepted Answer

11.5 mass %

Question 4

Which equation correctly expresses the relationship between vapor pressure and temperature according to the Clausius-Clapeyron equation?

Accepted Answer

$$\ln P_{vap} = -\frac{\Delta H_{vap}}{R} \frac{1}{T} + C$$

Question 5

Which of the following mixtures is classified as homogeneous?

Accepted Answer

Ethanol-water mixture

Question 6

Which statement about the solubility of gases in water is correct?

Accepted Answer

Gas solubility decreases as temperature increases.

Question 7

How many grams of KBr (molar mass = 119.10 g/mol) must be dissolved in 0.500 kg of water to prepare a 1.50 m KBr solution?

Accepted Answer

357 g

Question 8

Which of the following best describes the energetics of dissolution for most solutes?

Accepted Answer

Entropy increases and $$\Delta S_{soln} \u003e 0$$

Question 9

Which of the following is true about the solubility of most molecular and ionic solids?

Accepted Answer

Solubility increases with increasing temperature.

Question 10

According to Henry's law, what is the solubility of a gas in a liquid proportional to?

Accepted Answer

The partial pressure of the gas above the liquid

Question 11

Which of the following best explains why 'like dissolves like'?

Accepted Answer

When solute-solute, solvent-solvent, and solute-solvent forces are similar in kind and magnitude, dissolution is spontaneous.

Question 12

Which of the following is NOT a correct unit for expressing solution concentration?

Accepted Answer

Density (g/mL)

Question 13

A solution in which more than the equilibrium amount of solute has been dissolved is called:

Accepted Answer

Supersaturated

Question 14

Which of the following correctly defines molality ($$m$$)?

Accepted Answer

$$m = \frac{	ext{moles of solute}}{	ext{kilograms of solvent}}$$

Question 15

Which of the following is true about the phase diagram of carbon dioxide (CO$$_2$$)?

Accepted Answer

CO$$_2$$ sublimes at 1 atm and -78.5 $$^\circC.$$

Question 16

Which of the following is a correct expression for mass percent?

Accepted Answer

$$	ext{Mass percent} = \frac{	ext{mass of component}}{	ext{total mass of solution}} 	imes 100\%$$

Question 17

Which of the following statements about phase changes is correct?

Accepted Answer

Phase changes are changes in the physical form of a substance that leave its chemical identity intact.

Question 18

Which of the following is true about the effect of pressure on solubility?

Accepted Answer

Pressure has a strong effect on the solubility of gases but little effect on liquids and solids.

Question 19

Which of the following best describes the forces involved in metallic bonding?

Accepted Answer

Delocalized sharing of electrons described as bands of molecular orbitals (MOs)

Question 20

Which of the following is the correct formula for parts per million (ppm)?

Accepted Answer

$$	ext{ppm} = \frac{	ext{mass of component}}{	ext{total mass of solution}} 	imes 10^6$

Phase Diagrams, Solutions, and Solubility: Study Notes for General Chemistry

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