Notes
The Stoichiometry Law Breakers Concept Builder is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Concept Builder can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.
Teaching Ideas and Suggestions
For most chemistry teachers, stoichiometric conversions are reliant upon the use of the factor label method and conversion factors. Student tendency to take short-cuts, to ignore units, to post an answer without work, etc. are an annoyance as they violate the hours of classroom spent on teaching a skill that we believe to be more important than the answer itself. This Concept Builder focuses on that skill. There are no calculations. There are no numerical answers. Every question involves the evaluation of conversion factors. To answer a question, a student must inspect the conversion factor(s). They must ask questions like:
- Are the units in the correct place?
- Do the proper units cancel?
- Are the coefficients in the correct location in the mole ratio?
- Has the molar mass ratio been set up correctly?
Each question involves identifying the incorrect set(s) of conversion factors used to solve for an unknown. They have to find instances in which the law is broken. In the process of answering the questions, students will likely see their own mistakes. They will have opportunity to think thoughts like ...
- The problem doesn't start with the given quantity.
- The coeffients in the balanced equation are in the wrong place.
- The molar mass ratio should be grams over 1 mole.
- The molar mass ratio needs to be inverted as 1 mole over X grams.
Those students who understand conversion factors, will breeze right through the Concept Builder and feel like a Wizard. Those who struggle stand the chance to gain an immense amount through the exercise. "Aha" moments could be the norm for such students.
The Stoichiometry Law Breakers Concept Builder is comprised of 48 questions. The questions are organized into 12 Question Groups and spread across three different difficulty levels. Each question involves the same task - to identify any set of conversion factors that would NOT be capable of converting from the given quantity to the desired quantity. Each questions presents three reactions and a proposed conversion pathway for that reaction. Students tap to identify the pathways that are incorrect; there could be one, two, or three incorrect conversions paths. The Apprentice Difficulty Level involves mole-to-mole conversions. The Master Difficulty Level involves mole-to-mole-to-gram conversions. And the Wizard Difficulty Level involves gram-to-mole-to-mole-to-gram conversions. Each difficulty level consists of four question groups with four questions per question group. Students will be picked one question from within each question group at random. If they miss the question, then they will eventually be given two additional questions from within the group until they have answered two questions correctly in consecutive fashion.
This Concept Builder is intended as an in-class activity. Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in a separate file) in order to judge which activities would be most appropriate for their students.
The Stoichiometry Law Breakers Concept Builder is comprised of 48 questions. The questions are organized into 12 Question Groups and spread across three different difficulty levels. Each question involves the same task - to identify any set of conversion factors that would NOT be capable of converting from the given quantity to the desired quantity. Each questions presents three reactions and a proposed conversion pathway for that reaction. Students tap to identify the pathways that are incorrect; there could be one, two, or three incorrect conversions paths. The Apprentice Difficulty Level involves mole-to-mole conversions. The Master Difficulty Level involves mole-to-mole-to-gram conversions. And the Wizard Difficulty Level involves gram-to-mole-to-mole-to-gram conversions. Each difficulty level consists of four question groups with four questions per question group. Students will be picked one question from within each question group at random. If they miss the question, then they will eventually be given two additional questions from within the group until they have answered two questions correctly in consecutive fashion.
This Concept Builder is intended as an in-class activity. Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in a separate file) in order to judge which activities would be most appropriate for their students.
Health Bar
The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each question group is accompanied by a Help page that discusses the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.
Other Resources:
There are numerous resources on the site that address stoichiometry. We would like to hilight our wide collection of Calculator Pad problem sets. Calculator Pad problem sets consists of a short collection of chemistry (and physics) word problems that students must solve. Numbers within the problem are randomly generated so that each student receives a problem with a different answer. Students enter their answer in an answer blank and tap the Check Answer button. Feedback is immediate. Incorrect answers can be checked and corrected. For Task Tracker users, student results are saved. Teachers can view progress reports and scores of students. Task Tracker also allows teachers to edit the problem sets and even create their own problems and problem sets.
View Stoichiometry Problem Sets.
View Stoichiometry Problem Sets.