Unit 6 Solutions FE Review 25

Which of the following best describes how water molecules interact with dissolved ionic compounds?

• Water molecules surround ions, separating them due to polarity.

• Water molecules push ions together, forming larger crystals.

• Water molecules bond covalently with ions, changing the chemical composition.

• Water molecules repel ionic compounds, preventing them from dissolving.

Which of the following does NOT increase the rate of solute dissolution?

• Increasing the temperature of the solvent

• Stirring the solution

• Increasing the pressure above the solution

• Crushing the solute into smaller particles

A solution contains a dissolved ionic compound. Which of the following best explains why this solution conducts electricity?

• The solute molecules move faster when dissolved.

• The dissolved ions allow the flow of electric charge.

• The solute forms new covalent bonds with the solvent.

• The solute increases the density of the solution.

Tags

NGSS.MS-PS1-1

Which of the following correctly represents the dissociation equation for Fe2(SO4)3 in water?

• Fe2(SO4)3 (s) → Fe2(SO4)3 (aq)

Tags

NGSS.MS-PS1-2

A student wants to increase the solubility of a gas in water. Which of the following will achieve this?

• Decreasing the pressure on the solution

• Decreasing the temperature of the solution

• Increasing the temperature of the solution

• Stirring the solution vigorously

A scientist performs paper chromatography on a plant extract and observes four pigment bands. What factor determines how far each pigment travels?

• The pigment’s solubility in the solvent

• The pigment’s density

• The pigment’s boiling point

• The pigment’s molecular weight

A student prepares a solution by dissolving 50 g of KNO₃ in 100 g of water at 40°C. Based on the solubility curve, only 40 g of KNO₃ can dissolve at this temperature. What type of solution is formed?

• Unsaturated solution

• Supersaturated solution

• Saturated solution with undissolved solute

• Dilute solution

Tags

NGSS.MS-PS1-2

Which of the following statements about density is true?

• A solution with a lower mass-to-volume ratio has a higher density.

• Density is an intensive property and does not change with solution volume.

• Adding more solute to a solution always decreases its density.

• Density can only be calculated for solid substances.

A student takes 5.0 mL of a 3.0 M NaCl solution and dilutes it with water until the final volume is 10.0 mL. What is the new concentration of the solution?

• 1.5 M

• 3.0 M

• 6.0 M

• 0.75 M

During the Deepwater Horizon oil spill, hydrocarbons floated on the surface of seawater, while in a freshwater spill, some components sank. Why did this difference occur?

• The oil is more miscible in freshwater than seawater.

• The density of seawater is greater than that of freshwater.

• The molecular weight of oil changes in different environments.

• The temperature of the water affects oil’s solubility.