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Tutorials and iTRQs

Textbooks are filled with learning pathways in the form of guides, flow-charts, maps, approaches, and patterns. These learning pathways build and connect knowledge and facts in complex ways. It is this scaffolding of 'complex thinking' that allows the learner to engage in critical thinking when presented with a novel question. Unfortunately, many learners fail to accumulate this needed information at the appropriate time in the learning process. Tutorials and iTRQs are assignable online exercises that guide students along these learning pathways and assists them in building accurate and reliable mental connections.

General Chemistry I
Dimensional Analysis can be a difficult process to master in the first semester General Chemistry course. This method of solving problems by cancelling units is presented in four to five chapters in most textbooks as follows:

  1. English and Metric units of mass, length, area (length2) and volume are presented along with their conversion factors.
  2. Cubic length (length3) is presented and its conversion factor to volume is given as 1 mL = 1 cm3. In addition, density is introduced as a conversion factor between volume and mass.
  3. Moles and molecules are presented along with Avogadro's number. Also, the conversion factor of molar mass (derived from the Periodic Table) is introduced to allow the conversion between grams and moles.
  4. Students are taught how to balance equations and coefficient ratios are used in Factor-Unit problems as conversion factors between moles. At this point, a student is expected to solve a complex problem like

    If 3.45 ft3 of Hydrogen gas (DH2 = 0.0899 g/L) is burned in excess Oxygen, what volume (in nL) of water (DH2O = 1.00 g/mL) can be produced once the water vapor condenses to produce a liquid?

  5. Students are introduced to Molarity as the conversion factor between moles of a pure substance and Liters of a solution (usually aqueous) where the pure substance is the solute. At this point, a student is expected to solve a complex problem like

    If 34.5 mL of a 0.987 M NaCl is added to 30.2 mL of a 0.888 M AgNO3, how many mg of AgCl will be produced?

Some students experience difficulty with the more complex questions like the ones above because they have not constructed a "personal" concept map from information presented over several weeks and several chapters. These particular students benefit from pre-constructed HTML5-JS concept maps that are interactive and assignable. This "Learning Pathway" consists of clickable units that the student selects to "set up" a Dimensional Analysis problem. Next, the student must place the correct numbers in front of the units and label the units. The Map is also used to "set up" problems whose answers require two units, like density, molar mass, molar ratios or Molarity. It is important to note that "Learning Pathways" require students to answer a Dimensional Analysis problem exactly as they would find it answered in a textbook, answer guide or from their instructor. By forcing students to use a method that is "universally" taught in textbooks and classrooms, the learner is supplied with a guaranteed path to success that reinforces the presentation strategies used in textbooks and classrooms.

Click here to view Chem21Labs' Interactive Unit Maps.

Limiting Reagent problems present another challenge to students in the first semester of General Chemistry. An interactive TRQ (iTRQ - Limiting Reagent) has been created where students can "practice until they are successful." Either they correctly answer a limiting reagent question in a certain amount of time, or they correctly work through "x" questions by following an interactive, guided path.

General Chemistry II
Calculation of pH is probably the most difficult process to to master in the second semester of general chemistry. The Interactive pH Calculator "guides" students through this challenging maze by first having the student select the species impacting pH:

     
  • Strong Acid
  • Strong Base
  • Weak Acid
  • Weak Base
  • Strong Acid + Strong Base
  • Weak Acid + Weak Base
  • Strong Acid + Weak Base
  • Strong Acid + Weak Acid
  • Strong Base + Weak Acid
  • Strong Base + Weak Base
  • Buffer Solution + Strong Acid
  • Buffer Solution + Strong Base

Then as needed, ICE tables are filled in by the students and their calculations are checked at every stage. Students can opt to neglect "x", but if the test fails, they will have to use the quadratic equation. Finally, students are guided through the calculations of pH, pOH, [H3O+] and [OH-] with immediate feedback on their work.


Phase Diagrams and Heating Curves (open animation) is an interactive tutorial that makes a direct association between the phase changes in a phase diagram and the heat changes that occur in the solid ⇌ liquid ⇌ gas transitions. In the tutorial, students observe the impact of pressure and temperature on the phases of matter, contruct a phase diagram, name the various phase changes, and calculate the heat absorbed when water transitions through a phase change in a question similar to . . . .

64.5 g of ice at -25°C is heated to water at 89.9°C. How much energy in Joules was added?


Properties of Solutions (open animation) is an interactive tutorial where students discover that . . . .

Solute + Solvent = Solution

Additional "connections" (mass solute, moles solute, kg solvent, moles solvent, Liters solution) are introduced as drag/drop components that students place to create a map that shows the relationships of these five units to the equation above. Next, the equations to solve for Molarity, molality, mass percent, ppm, and mole fraction are connected to the newly created concept map. Finally, students must solve a problem like . . . .

12.5 g of NaCl is dissolved in 20.0 g water. Calculate the molality of the resulting solution if the density is 1.12 g/mL.

Organic Chemistry
Many students struggle when it comes to drawing organic mechanisms . . . . Chem21Labs has created re-assignable, interactive animations that, over time, will build the ability to write mechanisms for a variety of reactions. Once mastered, this same ability can be applied to any reactant containing a similar functional group. Click Writing Organic Mechanisms to draw the curved arrows in the following reactions:

  1. H2O + HCl
  2. Acetone + HBr
  3. Cyclohexene + Br2

A stereochemistry tutorial contains chiral molecules that can be rotated in 3D so students can determine R/S configuration or whether two stereoisomers are enantiomers or diastereomers.

Tutorials and iTRQs use 21st Century technology to create a "forced engagement" at a relatively high level of cognitive thought. Teacher can use this "coach-like" approach to schedule the intensity, duration and repetition schedule of academic work. Just like an athlete on a school team, some may not enjoy every part of the process . . . . but all will be thrilled with the results.