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Solutes and Solubility

Investigation 2 – PreLab









This Investigation is designed to help you to answer the following Focus Questions:

  • What affects the solubility of a solute? 
  • Can the rate of solubility of a solute be changed? 

Note: These questions are located in your SDR at the beginning and end of the Investigation.



Read the Background(s) in the Investigation. When finished, discuss the following concepts as a class:

  • Forces between the particles of a solute attract each other and hold them together.
  • Forces between the particles of the solvent also attract each other and hold them together.
  • When a solute dissolves, solvent particles surround the solute particles and destroy the forces holding them together.
  • As the solvent particles surround the solute particles, the forces holding the solvent particles together are also destroyed.
  • When the solute is completely dissolved, new forces have formed between the solute and solvent particles holding them together to form a solution.
  • Different solutes require different lengths of time to dissolve. This is called the rate of solubility.
  • The rate depends on how fast the solvent particles are able to surround the solute particles. It also depends on how fast the forces between the solute and solvent particles are formed.
  • The rate of solubility is defined as how much mass of a solute can be dissolved in a certain amount of time. It is written as the mass in grams divided by the time in minutes required for the solute to dissolve.



The following list includes Key Terms that are introduced in the Investigation Background(s). They should be used, as appropriate, by teachers and students during everyday classroom discourse.

  • properties
  • rate

Note: Definitions to these terms can be found on the Introduction page to the CELL.

Note: Additional words may be bolded within the Background(s). These words are not Key Terms and are strictly emphasized for exposure at this time.


  • Complete the Recall section in your SDR. 
    • What is solubility?
    • Can you change how solute particles and solvent particles interact?
    • Will a solute always require the same amount of time to dissolve in a solvent?
  • You will be using the same compounds that were used in Investigation One to test the effect of stirring on the rate of solubility.
  • Play the video below. Remember to follow along with your SDR and make any notes that you think might be helpful in the lab.
  • After the video, divide into lab groups to discuss strategy for the lab. For example, you may assign certain group members to perform specific functions during the lab.

Note: The purpose of the video is to allow you to anticipate the laboratory experience you will soon encounter. You should leave this PreLab session with a firm idea of what to expect and how to perform in the lab.

Note: Homework is posted below the video.


You should review the Investigation and video in preparation for the Lab.