Solutions (7.7D; 7.7E)

What is the term for the substance that dissolves in a solution?

• Solvent

• Solute

• Mixture

• Compound

Tags

TEKS.SCI.7.6D

Which of the following best describes a solvent in an aqueous solution?

• The substance that is dissolved

• The substance that does the dissolving

• The solid part of the mixture

• The gas in the solution

Tags

TEKS.SCI.7.6D

What happens to the concentration of a solution if more solute is added to the same amount of solvent?

• The concentration decreases

• The concentration increases

• The concentration stays the same

• The solution becomes a solid

Tags

TEKS.SCI.7.6D

Which process describes making a solution less concentrated by adding more solvent?

• Saturation

• Dilution

• Evaporation

• Filtration

Tags

TEKS.SCI.7.6D

Which factor increases the rate at which a solid solute dissolves in water?

• Decreasing temperature

• Decreasing surface area

• Stirring the solution

• Using less solvent

Tags

TEKS.SCI.7.6E

If you crush a sugar cube before adding it to water, what effect does this have on the rate of dissolution?

• It decreases the rate

• It increases the rate

• It has no effect

• It stops dissolution

Tags

TEKS.SCI.7.6E

A student wants to make a saltwater solution less concentrated. Describe a procedure the student could follow and explain why it works.

• Add more salt to the solution because it increases the amount of solute.

• Add more water to the solution because it increases the amount of solvent, which dilutes the solution.

• Heat the solution to evaporate water, making it less concentrated.

• Stir the solution to make it less concentrated.

Tags

TEKS.SCI.7.6D

How can the teacher increase the rate at which the solute dissolves?

 Choose 2 answers.

• Increase the surface area of the solute

• Agitate the solvent before adding the solute

• Increase the temperature of the solute/solvent mixture

• Decrease the surface area of the solute

• Let the solute/solvent mixture sit still until dissolved fully

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

A student is dissolving sugar in water. She wants the sugar to dissolve faster. She can either heat the water, stir the solution, or crush the sugar. Explain which combination of actions would be most effective and why.

• Only heat the water, because temperature is the only factor

• Stir and crush the sugar, but do not heat the water

• Heat the water, stir the solution, and crush the sugar, because all three increase the rate of dissolution

• Do nothing, as the rate cannot be changed

Tags

TEKS.SCI.7.6E

You are given a solid solute and want it to dissolve as quickly as possible in water. Design a step-by-step plan using temperature, surface area, and agitation, and explain how each step helps.

• Use cold water, keep the solute whole, and do not stir; these steps slow down dissolution.

• Use hot water, crush the solute to increase surface area, and stir the solution; these steps all increase the rate of dissolution.

• Use cold water, crush the solute, and do not stir; only surface area matters.

• Use hot water, keep the solute whole, and do not stir; only temperature matters.

Tags

TEKS.SCI.7.6E