Unit 6 FE Review 2.0

Which of the following actions would increase the concentration of a saltwater solution?

• Removing water from the solution

• Adding more water to the solution

• Stirring the solution continuously

• Lowering the temperature

A student dissolves 5.0 g of salt in 100.0 mL of water. Which change would increase the molarity of the solution?

• Adding 5.0 g more salt

• Adding 100.0 mL more water

• Filtering the solution

• Placing the solution in an ice bath

At 50°C, the solubility of KNO₃ is 80 g per 100 g of water. If 90 g of KNO₃ is added to 100 g of water at this temperature, what type of solution is formed?

• Unsaturated

• Supersaturated

• Saturated with precipitate

• Dilute

What will happen if a saturated solution is cooled without removing any solute?

• The solution becomes more concentrated

• The solution becomes unsaturated

• Excess solute may precipitate out

• The solution's molarity remains the same

What best explains why NaCl dissolves in water?

• It reacts chemically with water

• Water molecules form hydrogen bonds with the salt ions

• The polar water molecules surround and separate the ions

• The salt molecules share electrons with water

Which of the following will increase the rate of dissolution?

• Decreasing the temperature

• Increasing the volume of water

• Using larger solute chunks

• Stirring the mixture

Two liquids are poured into a beaker and do not mix. Liquid A floats on top of Liquid B. What conclusion can be drawn?

• Liquid A is more dense than Liquid B

• Liquid A is more soluble than Liquid B

• Liquid A has greater viscosity than Liquid B

• Liquid A is less dense than Liquid B

A student records the mass of a solution as 42.8 g and the volume as 16.0 mL. What is the density of the solution?

• 0.27 g/mL

• 2.67 g/mL

• 1.39 g/mL

• 0.38 g/mL

What method is best for separating colored components of ink?

• Filtration

• Chromatography

• Distillation

• Decanting

During a chromatography lab, green and yellow pigments traveled the same distance on a paper strip. What can the student conclude?

• The pigments have the same mass

• The pigments have the same solubility

• The pigments are chemically bonded

• The pigments are insoluble