Initial Planning Reflection for - An Activity Sequence on Solutions


Solution is a substance that has characteristics / properties, such as density, a boiling point, and solubility, all of which are independent of the amount of the sample. A solution is different, but related to a mixture of substances often can be separated into the original substances using one or more of the characteristic properties.

Possible Related Concepts

  • Solution is a combination of a solvent and solute so that the solvent contains a solute distributed proportionately throughout the solvent.
  • Solvent substance that is able to dissolve a solute
  • Solute is a substance that can be dissolved by the solvent.
  • Dissolve is when a liquid has the property to distribute a substance throughout the liquid in a proportional manner.
  • Solubility is the ability of a substance to go into a solution.
  • Liquid is a state of matter where the liquid substance has the property of flowing. Particularly flowing within a container so that its shape will fit the shape of the container in such a manner that it will match the bottom and the sides with the top flattening perpendicular to the force of gravity or any other force that acts upon it.
  • Mixture a combination of different solid materials arranged in a random order depending on the solid materials interaction with other particles in the mixture and any forces acting upon them.

What instructional theory and learning theory should be used to begin to facilitate student learning for these ideas?

I would want to begin with exploration so the students will learn through their own actions and reactions in a new situation.  If they explore new materials and new ideas with minimal guidance or expectation of specific accomplishments, the new experience should raise questions they cannot answer with their present ideas and patterns of reasoning.  Having made an effort that most likely will not be completely successful, they should be motivated to ask questions and begin to look for ideas that will lead them to self-regulation. Meanwhile, I will have collected enough assessment data to begin to know what they understand and where I might begin to facilitate their learning in the second phase: invention.

What activities could be used for the first activity with students?

Activities Review a resource file or a list of possible activities that would fit the concepts and generalization.

List of possible activities

1.  Showing a video with scenes of crystals dissolving or being formed (time lapse), along with animated sequences showing the same phenomena at the atomic-molecular level, with the particles represented by small moving circles or squares of various colors being joined or separated by adding or removing lines.

2.  Arranging an activity in which you students use water to dissolve colorless and colorful substances, observe schlieren, compare cloudiness or transparency of solution, and let the solutions evaporate.

3. Providing students with rice crispies or rice chex and have them create a model for a soluti9on and a non solution and explain the difference molecular model sets so they

4.  Presenting a demonstration with explanation on the dynamic nature of liquids, how the equilibrium of a liquid changes with the addition of a solute to a liquid that is a solvent; and the changes that occur in the solution with the addition or evaporation of the solvent, and the effect of temperature changes.

5.  Arrange an activity in which students carefully measure the amounts of solvent and solute they allow to interact so as to determine the solubility of one or two substances at several temperatures.

Making a decision

Review what resources are needed for each activity and the preparation of students needed for each activity. Eliminate activities that wouldn't fit the availability of resources and the readiness of students (mixtures). Then think about how each would or would not be good to use as the first activity.choice.  When you have done that, compare the ideas below with yours, and if possible, with those of others.

1.  Videos are popular ways of introducing new topics.  In this case, the video combines observations the students might make in the laboratory with theoretical ideas derived from the kinetic theory.  The video would be better used after a direct experience.  Videos raise questions, provide inquiry, or present contradictions less effectively than first hand experiences.  Since paying attention to the video preempts the viewers’ initiative, few students watching the video for the first time would think critically about what they observe.  Additionally, seeing a picture of an object or process does not carry the impact of handling the object or influencing the process oneself.

2.  This is highly recommended.  The students have a great deal of freedom to use their own judgment, try out their own ideas, and learn from their own mistakes as they gain practical experience with materials they will study later.  The teacher can evaluate the reasoning patterns the students use and later provide more direction or extend the investigations as needed.

3.  Even though this approach involves students in concrete manipulations, they are being required to create representations of molecules or particles and themselves.  Recognizing the ways in which a model represents and the ways in which it does not, requires formal reasoning operations, or a collecting of understandable observations to associate the model that a newcomer to the topic is unlikely to have.

4.  This theoretical approach, often in the form of a lecture, would be completely inappropriate for the introduction of a new topic, because it takes for granted that he student have a good grasp of concentration, equilibrium, temperature, and density.  Also the teacher has no chance to evaluate the student’s preconceptions since the learners are passive.

5.  This type of activity discourages students from asking their own questions and taking responsibility for satisfying their own curiosity.  The reason for making the careful observations, waiting for equilibrium to be established, and varying the temperature will not be clear at this time either.  Such an activity would be more appropriate at a later stage of sequence, but even then it might focus attention on the transient processes while equilibrium is being established.

Reflect on the positives and negatives for each and make a decision as to what you believe might be the best before continuing.

  The recommended approach is number two. It is an example of an exploratory activity upon which later conceptual understandings can be built.  It can represent the exploration phase of a three-phase learning cycle based on current theories of learning and designed to encourage self-regulation.  The three phases of the entire learning cycle are called exploration, concept invention, and concept expansion (Sunal & Sunal).




Dr. Robert Sweetland's Notes ©